general discussion on cancer
prostate cancer
Skin Cancer and Melanoma

Introduction and Background

Cancer is not a single disease. There are over 200 types of cancer afflicting individuals of all ages. It is also not necessarily a fatal disease. Depending on the type, some cancers are completely curable in over 95% of the cases, whereas other types of cancers are nearly always fatal.

Overall, cancer is the second leading cause of death in the U.S. for all ages, accounting for 22% of all deaths. The percentage of deaths due to cancer tends to peak in the years of early childhood and then again in mid to late adult life. According to the American Cancer Society, this year 563,100 Americans will die of cancer—more than 1500 people per day.

Despite these statistics, relative survival rates for cancer have been steadily climbing over the past several decades. According to the National Cancer Institute, 53% of individuals diagnosed with cancer now survive at least 5 years from their diagnosis. Although certainly a serious condition, the diagnosis of cancer is clearly no longer a hopeless one.

What is Cancer?

Cancer is an uncontrolled proliferation of certain abnormal cell types in the body that invade surrounding normal tissue. The cell type and location determine the type of cancer. Cancers can be found in solid tissue or in tissues of the bone marrow, blood or lymph tissues. Cancer does its damage to the host by growing rapidly and robbing normal cells of nutrients. Additionally, cancer can spread to other areas, a process called metastasis. Cancers can cause secondary problems by obstructing organs, eroding tissue, causing swelling or seizures when found in the brain, or preventing the normal development of different types of blood cells.

Common Forms of Cancer

The most common form of cancer in the U.S. for both men and women, is non-melanoma skin cancer, with about 700,000 new cases annually. The majority of these are basal cell carcinomas (80%), while the remainder are predominantly squamous cell carcinomas. Cumulative exposure to ultraviolet sunlight radiation is the principal risk factor associated with this form of cancer. Fortunately, such cancers are amenable to surgical treatment, with relatively high success rates.

Each year about 1.3 million new cases of other cancers (besides non-melanoma skin cancers) are diagnosed in the U.S. The most common of these in men are prostate, lung, colon, bladder, and rectal cancer. For women, the most common new cancers in order of decreasing frequency, are breast, lung, colon, uterine, and ovarian cancers.

If ordered according to the cancers that cause the most deaths, the lists change slightly because some cancers have a greater potential for response to treatment than others. When forms of cancers are viewed in this manner, the top three most lethal cancers for men remain the same: lung, prostate, and colon, but pancreatic and stomach cancers now appear as fourth and fifth on the list. For women, the most common causes of cancer deaths are due to lung, breast, colon, ovarian, and pancreatic cancers, in that order.

Studies of Cancer in Pilots

Although several long-term studies have reviewed the occurrence of cancers in pilots, there is no broad consensus that has emerged within the aerospace medicine community regarding those forms of cancers that may occur more frequently in aviators. Results have varied depending on the size of the study, the number of years spanned, the comparison groups used, and the type/reliability of data available for use.

In studies that have focused on aviator deaths due to cancer, one review of 1538 U.S. commercial pilots and navigators suggested that deaths due to kidney cancers might be occurring more frequently than in the general population. Another large British study of 6209 pilots did not confirm the finding of increased kidney cancer deaths, but instead found that the occurrence of deaths attributed to melanomas was significant.

Some studies that looked at frequency of occurrence, rather than death reports, have shown higher rates of urologic cancers like prostate (Canadian study), bladder, and testicular (US Air Force study) cancers. Other studies suggest that pilots actually have decreased rates of certain cancers and other diseases. These findings may perhaps be related to their higher socioeconomic status, frequency of medical surveillance, availability of early medical care, and pre-selection for health. As more data accumulates with time, more reliable conclusions will no doubt become available, and allow for more definitive assessments of cancer risk in commercial pilots.

Although not available online, an excellent review article and synopsis of all scientific studies of cancer in aircrew members to date (meta-analysis) can be found in the journal Aviation, Space and Environmental Medicine, 2000; 71:216-24 "Cancer Incidence and Mortality Among Flight Personnel: A Meta-Analysis" Ballard et al. It concludes that there were slight increased incidence of cancers of the brain and melanoma in male pilots, who also had an increased mortality risk from prostate and brain cancer. The risk of other types of cancer was lower in pilots. Female flight attendants had higher risks of melanoma and breast cancer. The cause for these findings is not clear since it is difficult to separate occupational exposures from routine exposures such as potential for more sun with increased access to travel and potentially increased leisure time.

Stages of Cancer

"Staging" of cancer is a means to help categorize the severity of the disease, establish a prognosis for the individual, and determine a recommended treatment for the condition based on the location and severity of the disease.

A current standard format for staging includes the TMN classification. "T" refers to the size or location of the tumour at its original (or "primary") site, and whether it has extended to local tissue. "N" refers to the involvement of any lymph nodes. "M" refers to the presence of tumour cells in more distant metastatic sites.

Alternatively, a four-staged, Roman numeral classification is often used. The stages in this system reflect the extensiveness of the cancer, with Stage I being the least extensive and Stage IV being the most extensive. Colon cancer uses a "Duke's" classification with the earliest stage term "Duke's A" and the most advanced being a "Duke's D". Using these forms of staging does not preclude also categorizing cancer in the TMN classification.

Additionally, cancers can be categorized as to how closely they resemble the original tissue from the primary site. "Well differentiated" cancers resemble the original tissue fairly closely and are considered less severe. "Moderately differentiated" tissues are intermediate in severity and "poorly differentiated" cancers indicate a more serious and aggressive disease. Prostate cancer uses a "Gleason" scale to characterize the differentiation of the cells with higher numbers indicating more poorly differentiated cancers.

Screening for Cancer

Some types of cancer have well-developed screening tests, which attempt to detect disease before it is fully established or at an early enough stage where a cure is likely. Examples include the Papanicolaou smear (PAP) for cervical cancer. Tests such as the prostate specific antigen (PSA) for prostate cancer, a mammogram for breast cancer, or colonoscopies and stool sampling for colon cancers are examples of screening to detect early disease at a hopefully curable stage. An article in American Family Physician contains a very useful discussion of cancer screening benefits and pitfalls. A follow-up article gives a superb outline of Cancer Screening Guidelines.

Other types of cancers do not have effective screening tests but do have chemical indicators possibly indicative of the presence of a tumour. One such example is the carcinoembryonic antigen (CEA) level for colon cancer. Many other proxies for cancer detection exist. Lung cancer is the leading cause of cancer deaths in both men and women. Unfortunately, there is no effective screening test available to detect early stages of lung cancer. By the time lung cancer is visible on a chest x-ray, the chances for curing the disease are minimal. Likewise, there is no effective serum tumour marker for lung cancer. New treatment protocols and clinical studies at research institutions may offer improved survival and quality of life in some cases of cancer discovered in later stages.

Other than PAP smears and mammography, most screening tests for cancer do not have broad acceptance or scientific evidence to support their routine use in all populations. Colon cancer screening is slowly gaining acceptance, particularly with a variety of testing methods available. See American Family Physician "Recent Developments in Colorectal Cancer Screening and Prevention" for more information. An additional article, "Virtual Endoscopy: A Promising New Technology", discusses potential future technology for cancer screening.

Positive screening tests generally lead to definitive follow-up evaluations, some of which can involve relatively invasive procedures. This can result in a risk of complications and increased cost for an individual who does not have the disease, but instead simply had an initial test that was a false positive.

Causes of Cancer

Many different factors are considered to place individuals at increased risk for cancer, and each specific type of cancer has its own unique set of risk factors. The strongest associations between risk factors and cancers appear to occur with smoking, radiation exposures, and other lifestyle factors such as diet, alcohol use, and others. A strong family history of a particular type of cancer may also lead an individual to seek early screening for this type of disease.

The use of tobacco, in particular, is felt to be responsible for the development of more cancers than all other causes combined. Those people who knowingly choose to use tobacco products are placing themselves and those around them at increased risk for a significant number of cancers. Exposure to radiation in the form of occupational hazards, natural hazards ( radon and cosmic radiation) and man-made exposures (primarily medical diagnostic tests and treatments), can also pose significant hazards. Recent public education about the hazards of radon in homes causing lung cancer and the role of ultraviolet light in causing skin cancer may reduce the upward trends in these specific diseases. The National Cancer Institute is constantly researching for conducting research to determine avoidable causes of cancer in the general population.

From an aeromedical perspective, the windscreens and metallic skin of aircraft shield flight crews from ultraviolet radiation. Studies are underway to determine if aircrew are exposed to significantly elevated levels of cosmic radiation, and if so, whether aviators are at a resulting increased risk for any form of cancer.

Diagnosis of Cancer

The diagnosis of cancer is usually made by obtaining a piece of tissue to be studied under a microscope. A physician with specialized training in pathology determines whether the tissue is normal or has changes indicative of cancer. This piece of tissue is called a biopsy specimen may be obtained through the skin using a hollow-core needle, by direct surgical excision, or with the aid of various forms of fiberoptic scopes and biopsy forceps.

Possible indications of cancer may also be detected with laboratory studies, testing for tumour markers in the blood, or revealing abnormalities in the function of organs, which may be the site of metastases, such as the liver. Nuclear medicine scans using radioisotopes can also reveal primary and metastatic cancers. Scanning techniques using MRI or CT technology and ultrasound may also reveal the presence of tumours. The screening techniques are constantly being evaluated as noted in the recent US Preventive Services Task Force report on ovarian cancer.

Treatments for Cancer

There are a number of possible treatments for cancer. Each type of cancer has its own specific set of medically accepted treatments. Additionally, experimental treatments for cancer are continually being developed. Western medical treatments for cancer include surgical excision or debulking, radiation therapy, chemotherapy, immunotherapy, thermal therapy, hormonal therapy, and the newly evolving gene therapy. Complimentary and alternative medicine practitioners have a host of alternate recommendations for cancer. All medical models encourage optimum nutrition and emotional well being. Additionally, since cancer survivors are susceptible to recurrence of the disease, continued close medical follow up is essential. Finally, some individuals with cancer elect not to undergo treatment at all, for individual reasons.

Surgery

Surgical treatments of cancer are generally designed to remove all of the primary cancer. If a particular type of cancer is slow growing and confined to a specific area, surgical removal of the primary cancer may represent a cure. Common examples include early forms of prostate, colon, thyroid, cervical and endometrial cancers. Surgery might also be used to remove metastatic lesions in attempt to slow the progress of the disease, or alleviate symptoms caused by their particular location. For example, surgical excision is used to debulk or reduce the size of the primary tumour or a metastasis that may be affecting other organs, such as an abdominal cancer that is blocking the small intestine.

Radiation Therapy

Radiation therapy uses high dose, focused radiation beams to kill rapidly growing tumour cells. "Local radiation" uses x-ray beams from two different sources to focus on tumour cells in a circumscribed area.

"Whole body radiation" is often used in certain types of cancer of the blood-forming organs, such as leukemias. This type of treatment may require a subsequent bone marrow transplant procedure to restore the individual’s capacity to produce blood cells.

Another form of radiation treatment, called brachytherapy, makes use of implanted radioactive "seeds" within cancerous tissue to kill the tissue locally. Prostate cancer is an example of where such implants are commonly used.

Chemotherapy

Chemotherapy employs a variety of different pharmaceuticals and chemicals that can adversely affect normal cells, while targeted cancer cells are being destroyed. For this reason, people often get very sick when undergoing treatment with chemotherapy. Because cancer cells are growing more rapidly than normal cells, the cancer cells presumably take up the chemotherapeutic agents faster than surrounding cells and will be killed sooner. Unfortunately, to ensure adequate kill rates for cancerous cells, normal cells may also be affected, and as a result, normal body functions can be interrupted. For example, the rapidly reproducing cells such as those of the hair and lining of the gastrointestinal tract are frequently injured causing the symptoms of nausea, vomiting, diarrhoea, and hair loss.

Immunotherapy

A newly evolving field of cancer treatment involves injecting the individual with proteins and other compounds that bind specifically to tumour cells and kill the cells through a variety of mechanisms. An example of this technology has been applied to the treatment of malignant melanomas. Antibodies against the tumour cells are genetically spliced into non-pathologic micro organisms that are injected in the body, where they produce the antibodies that seek out and kill malignant cells.

Thermal Therapy

Another new technique for treating cancer is the use of heat or cold focused on the tumour to kill the malignant cells. Temperature changes may be induced by physical, chemical or microwave energies.

Hormonal Therapy

Hormonal therapy is frequently used when tumour cells are sensitive to levels of hormones in the body. By depriving the tumour cells of the hormone, the growth of the tumour is slowed, arrested or reversed. Examples include the use of tamoxifen for breast cancer and the use of Lupron for prostate cancer.

Gene Therapy

The newest area of research and cancer treatment involves gene therapy. In this technique, genes specific for cancer are substituted within the tumor chromosome with more benign genes, using a technique similar to gene splicing.

Observation

Finally, some individuals elect to not undergo any treatment for cancer. The reasons for this decision are varied. In some cases, the cancer grows slowly enough that it is not likely to cause significant illness or discomfort before the individual’s expected death from other causes. Examples include chronic lymphocytic leukemia and prostate carcinoma in older individuals. Some individuals have cancer that has progressed far enough at the time of discovery that any intervention is unlikely to significantly alter quality of life or longevity. In such cases, further treatment can inflict more pain and discomfort than symptomatic treatment alone. Pancreatic carcinoma is frequently in this category. The third possible reason for not undergoing treatment for cancer by traditional Western means would include a lack of confidence in conventional cancer treatment versus alternative treatments, or dissatisfaction with the toxicity of traditional treatments.

Determinants of Prognosis

Prognosis for any given type of cancer is dependent on many factors. These factors include the type of cancer, the stage of disease when discovered, the aggressiveness of the individual cancer, cell type, the types of treatment available, co-existing diseases and the general health of the individual. Any individual with cancer should remember that a prognosis is simply medical sciences’ best guess based on a large population with similar diseases. Any single individual can behave quite differently than the generally accepted prognosis. Individuals having experiences outside the standard prognoses are often termed as "having beat the odds", "having experienced a miracle" or "having a surprisingly rapid demise."

FAA Policy on Cancer

Cancer is a disqualifying condition according to current FAA policy. Pilots diagnosed with cancer are obligated under FAR Part 61.53 to ground themselves until their case is reviewed by the FAA. Exceptions to this rule involve certain superficial, non-melanoma skin cancers that have been completely excised. In such cases, pilots may return to flight duty and report the condition at the time of their next physical.

Most other cancers, however, require documentation of successful removal of the tumour, completion of any therapy, and the absence of metastatic disease before the FAA will favourably consider an airman’s application for a medical certificate. In some cases, the pilot may still be undergoing treatment for disease and be certified. A common example is the use of hormonal suppressive therapy in prostate carcinoma.

The current FAA policy for metastatic cancer requiring intravenous chemotherapy is for a one-year observation period to pass following surgical removal of the tumour. The chemotherapy course must be completed before the case will be considered for certification. Distant metastases not involving the central nervous system may require a three year observation period before recertification consideration. Because of the increased risk of brain involvement with metastatic breast cancer, lung cancer, and malignant melanoma, the resulting potential for seizures or cognitive dysfunction with these metastatic cancers require specific protocols for mandatory observation periods following their treatment. If spread to the central nervous system does occur, a five-year observation period is mandatory before recertification is possible. The FAA formalized this policy in October 1999.

In general, pilots with a history of cancer will be granted a Special Issuance medical certificate allowing the pilot to fly for a limited period of time under their medical certificate. Controllers are granted Special Consideration in the same fashion. Instead of the certificate lapsing to a lower class of certificate, the medical will expire for all classes pending resubmission of updated medical information and a current status report from the treating physician regarding the controller or pilot’s continued freedom from cancer. You may also want to read our article regarding Aeromedical Certification for more details on this process.

Recommendations

Numerous world and national scientific health organizations recommend a variety of lifestyle modifications to lower an individual’s risk of cancer. The most widely recommended and accepted measure is avoidance of tobacco products. Some estimates state that the rate of new cancer cases would be cut in half by avoidance of tobacco use. An additional protective measure against some types of skin cancer is provided by the use of sunscreens that block harmful UV rays. Homes that are found to have elevated radon levels should have effective abatement equipment installed to lower the risk of non-tobacco related lung cancer.

One of the simplest interventions involves changing an individual’s diet to one rich in fruits, vegetables, anti-oxidants, and fibre. Decreasing high dietary fats, which have been associated with colon cancer, is an added protective step. See a patient handout from the American Academy of Family Practice on Food Choices to Help Reduce Your Risk of Cancer.

The American Cancer Society has published 2002 Guidelines for Nutrition and Physical Activity for the Prevention of Cancer. This document gives excellent advice of proven, postulated, unproven and harmful interventions for many types of cancer. Of note, moderate regular physical activity is beneficial for nearly every type of cancer.

Finally, each individual should discuss cancer-screening techniques with their attending health care provider to determine which tests may be most appropriate for them.

Sources of Information

Many reputable sources of information on cancer prevention, detection, treatment, and recovery are widely available. These include the American Cancer Society (1-800-ACS.2345) and the National Cancer Institute of the National Institutes of Health (1-800-4-CANCER). See our Links section below.

Prostate Cancer

Introduction

Prostate cancer is a very common condition that increases in frequency as men grow older. Although the disease may be very serious and lead to death, most cases are curable if detected early and treated. Many pilots and controllers fear losing their FAA medical certification if they are diagnosed with prostate cancer and put off regular examinations to avoid the requirement to report this to the FAA. We encourage regular evaluations with your physician for this treatable disease.

Approximately 200,000 cases of prostate cancer are diagnosed in American men annually. Nearly 32,000 men will die of this disease each year. However, if detected early, the cure rate for prostate cancer is almost 100%.

The primary risk factor for prostate cancer is increasing age, particularly over age 50, with half of all cancers occurring after age 65. African-American men have twice the rate of prostate cancer as do white American men.

Screening Tests

Two primary tests screen for prostate cancer: the Digital rectal Exam (DRE) or "finger wave" and the Prostate Specific Antigen (PSA) blood test. Neither is adequate alone; the tests are complementary. Most men should be screened by age 50, or sooner if they have a history of prostate cancer in the family. An editorial in American Family Physician describes the risks and benefits of various types of screening for prostate cancer "Counselling Patients about Prostate Cancer Screening".

If a nodule (lump) is detected on DRE or if PSA levels are elevated and/or rising on repeat testing, your physician may recommend a transrectal ultrasound (TRUS) to further define any irregularities that may be prostate cancer.

If a nodule is confirmed or there are other indications of prostate abnormalities, the next step is a biopsy of the prostate. The biopsy is obtained by using a needle inserted in the prostate gland to remove a sample of tissue. This sample is studied by a pathologist who determines if the prostate is normal or if it contains cancer cells. If cancer is found, it is "classified" according to how aggressive it appears using the Gleason scale. Most men describe the biopsy as uncomfortable but not seriously painful.

Other Causes of PSA Elevation

Another common cause of mildly elevated PSA tests and enlargement of the prostate is Benign Prostatic Hypertrophy (BPH). This is a universal condition in older men who may notice a less forceful urine stream, prolonged urination and waking up at night to urinate.

There is some controversy over the relative risks and benefits of screening low risk men for prostate cancer with PSA alone. Please see the Health Technology Assessment Committee report on Prostate Specific Antigen as a Routine Screening Test for Prostate Cancer in Asymptomatic Men, June 1995 (Executive Summary). A more recent review of the potential benefits and risks of prostate cancer screening is available in the May 3, 2001 issue of the New England Journal of Medicine.

Cancer Treatment Options

If prostate cancer is diagnosed, your physician will discuss treatment options with you. One option is watchful waiting with frequent DRE and PSA testing. In many cases, pilots may fly after appropriate reporting to the FAA while under careful observation. Controllers will require specific clearance from the Regional Flight Surgeon.

Surgical Options and Staging

Many men with prostate cancer elect to have the prostate removed. The procedure is called prostatectomy. It can be done by several techniques. The major complication from prostatectomy is the possibility of impotence or impaired sexual functioning. A new technique called the "nerve sparing prostatectomy" may decrease this complication rate. At the time of surgery, the surgeon and the pathologist will determine if the cancer is confined to the prostate or has spread to surrounding areas. This process is called "staging". If the cancer has grown beyond the prostate, but not to isolated and distant areas, this is called local extension. If the prostate has spread to distant areas, the term is "metastatic" cancer. Frequently, if a surgeon suspects distant spread, they may recommend additional blood tests or diagnostics scans, (CT, MRI, radionuclide studies). The results of these tests determine treatment recommendations.

In most cases, the cancer is confined to the prostate and surgery cures the condition. After a recovery period of several weeks, the individual may return to full activity with continued periodic monitoring. Monitoring is frequently done with periodic measurement of PSA levels. At this point, reporting the condition to the FAA may begin so that the pilot can obtain clearance to resume flying. Controllers have to get clearance through the Regional Flight Surgeon. An article in JAMA describes the prognosis for men with elevated PSA levels after prostate surgery.

Alternatives to Surgery

Several alternatives to surgical treatment exist. Microwave treatment of the prostate is a very new treatment option . A probe inserted into the penis can "cook" the cancer in the prostate. Because it is a new treatment, long term success and complications are not yet well documented. A similar investigational treatment is cryosurgery which freezes the prostate using a penile probe similar to the microwave therapy. Both types of treatment may not be covered by insurance companies since they are not yet widely accepted. Both are a viable treatment options when reporting to the FAA.

Radiation Therapy - External Beam

Radiation to the prostate cancer is a third treatment option. Frequently radiation is recommended as an adjunct to surgery if the cancer has spread beyond the prostate. Two forms of radiation delivery exist. The first is External Beam radiation (EBR) . This uses radiation "guns" to shoot the prostate through the skin with doses spread over weeks to months. The FAA will not certify pilots to fly or controllers to work while they are undergoing EBR. The major complications are skin irritation and breakdown (painful sitting) and delayed impotence. Proton irradiation may decrease these complications.

Radiation Therapy- Seed Implantation

The second form of radiation delivery, also known as brachytherapy, is radium seed implantation. These are "splinters" of a radioactive material that are inserted into the prostate similar to a biopsy technique. They deliver radiation to the prostate over extended periods of time. Again, impotence is a potential complication but skin breakdown is less common. The FAA has certified pilots to fly while the have Radium seed implants to treat an otherwise controlled cancer. Controllers require specific clearance from the Regional Flight Surgeon.

High-Dose Rate Brachytherapy

A third form of radiation delivery is high-dose rate (HDR) brachytherapy. In this form of treatment, a highly radioactive Iridium-192 source is welded to a wire used inside of a catheter. The Iriduim source is advanced in half centimetre increments directly within the tumour. Because of the high dose, only a few minutes of exposure are required in 3-10 sessions for treatment. The wire is withdrawn at the end of each treatment, thus the individual has no permanent radiation source as with radium seed implants. Radiation damage to surrounding healthy tissues is minimized.

Chemotherapy

Chemotherapy used toxic medications to attempt to kill cancer cells. Chemotherapy is not very successful in prostate cancer and is not used as the only treatment for the condition. It may be used as an "adjunct" or additional therapy to surgery or radiation. Because it is not tolerated very well by those who are candidates for this treatment, the FAA generally does not waive pilots to fly or controllers to control when they are on this treatment. Other forms of medications are better tolerated in prostate cancer and potentially more effective. They are directed at manipulating hormone levels that may slow the progression of prostate cancer.

Hormone Therapy

The final therapy for prostate cancer involves hormone therapy. Hormones that inhibit testosterone block a stimulus for prostate growth. They include Casodex (bicalutamide) and Eulexin (flutamide). Other hormones inhibit the release of hormones that stimulate testosterone. They include Lupron (leuprolide) and Zoladex (goseralen). Usually hormones from each category are given simultaneously. The major side effects include hot flashes and sweating. The FAA will recertify airmen and controllers taking hormones for this condition.

Watchful Waiting

Prostate cancer is the most common cancer in adult men, but is not the most common cause of cancer deaths. Some cases are relatively slow growing and pose little immediate risk to an individual. These cases may not require immediate treatment, but can be followed with careful monitoring. This approach, termed “Watchful Waiting”, is sometimes recommended in early stages of low grade, slow growing prostate cancer and in older gentlemen. This may reduce the risk of impaired sexual function and loss of bladder control some men experience with other treatments for prostate cancer. Monitoring of the PSA level on a frequent basis is critical for this approach. A rise in the PSA may signal a transition to a more aggressive type of cancer or spread of the cancer.

A liberalization of the FAA’s earlier policy on prostate cancer now allows pilots and controllers to continue to fly and control with a confirmed diagnosis of prostate cancer, even with out treatment, in some circumstances. The FAA policy authorizes individuals to fly/control, after FAA review and approval, if the prostate cancer is well documented as low grade (not aggressive and growing rapidly) and confined to the capsule of the prostate. Regular reports to the FAA are required.

Other Treatment Options

New treatment options are being being considered. Some involve a probe introduced through the penis to freeze or microwave the cancerous tissue and destroy it. Clinical trials are often being conducted to evaluate new treatment options.

FAA Certification

FAA certification after diagnosis of prostate cancer generally requires the operative report and hospital discharge summary (if any), pathology and laboratory reports, the results of any scans or tests for metastatic disease and a statement from the treating physician that the pilot may return to full activity. The physician statement should mention what follow-up evaluations are scheduled and the dosages of any medications.

This documentation can be submitted directly to the FAA, but pilots and controllers are cautioned that most clinical specialists are not trained to recognize all of the aeromedically relevant aspects of a case. Erroneous or incomplete information can result in significant delays in certification. Once an airman or controller is returned to duty, the FAA will generally require a Current Status Report from your treating physician at the time of your next FAA medical examination.

An excellent summary of prostate cancer is published in the Spring 2005 issue of the Federal Air Surgeon's Medical Bulletin.

Skin Cancer and Melanoma

Introduction


Over 1,350,000 new cases of skin cancer will be diagnosed in Americans in 2001. Most cases are preventable and for those that do occur, many are treatable. One type of skin cancer, malignant melanoma, is often lethal. Reducing exposure to the sun and ultraviolet radiation is the cornerstone of prevention. Regular skin examination is the key to early detection and cure. FAA policy on medical certification of pilots with skin cancer depends on the type of cancer and extent of disease.

Types of Skin Cancer

Skin cancer is generally divided into two major categories: melanoma and non-melanoma skin cancers. There are several sub-groups of malignant melanoma, and two major types of non-melanoma skin cancers: basal cell carcinoma and squamous cell carcinoma. Bowen’s Disease is considered an early form of squamous cell carcinoma. Other non-melanoma skin cancers make up less than 1% of all skin cancers.

Statistics

One in six Americans will have some form of skin cancer in their lifetime. Of the 1.3 million cases of skin cancer projected in Americans in 2001, approximately 75% (one million) will be basal cell carcinoma. The five-year survival rate for basal cell carcinomas is near 99%. In other words, only 1% of people diagnosed with basal cell carcinoma will die of the disease within five years of the diagnosis.

Nearly 250,000 cases of squamous cell carcinoma will occur in 2001, about 20% of all American skin cancers. The five-year survival rate is 95%. The number of deaths from both basal cell and squamous cell carcinoma is 2,000 per year. Approximately 80% of skin cancers are caused by sun exposure.

Melanomas, though relatively small in number, are the most serious type of skin cancers. Approximately 54,000 cases of melanoma will occur in Americans in 2001, only 4% of all skin cancers. Melanoma is the 8th most common cancer in the United States. The incidence of melanoma is rising rapidly with a nearly 15-fold increase in incidence between 1935 and 1993. However, the 7,800 deaths make up over 80% of the total number of fatalities from skin cancer. Two thirds of the deaths will be in men and one third in women. The five-year survival rate for all melanomas is 88% and nearly 96% in “localized” melanoma.

Risk Factors

Numerous risk factors exist for all types of skin cancer. Some factors are controllable, while others are not. Those not modifiable are gender, natural skin pigmentation, age and immune system status. Males have 2-3 times the risk of all types of skin cancers than females. Over half of all skin cancers occur in people over age 50. Persons with fair skin have significantly higher risk than those with dark skin. Fair skinned white individuals have four times the risk as olive skinned Caucasians and twenty times the risk of African Americans.

Modifiable risk factors include sun exposure and UV radiation doses, cigarette smoking, sexual contact with human papillomavirus, chemical exposures and certain medications. The easiest to control is sun exposure and UV radiation.

Non-melanoma skin cancers (basal cell and squamous cell carcinoma) are related to cumulative sun exposure over a lifetime. Therefore, incidence increases with age. Fair skinned people living near the equator are at highest risk. Recently, individuals of higher income and more leisure time have documented increased risks for these cancers, presumably due to increase time exposed to the sun. Many of these individuals will have pre-cancerous changes in their skin.

Melanomas are not directly related to chronic sun exposure, but rather to a history of brief, intense, blistering sun exposure, particularly as a child or adolescent. Over 80% of most individuals' total body exposure to sun occurs by age 18 years.

Location and Spread (Metastasis)

The non-melanoma skin cancers are most commonly found on the face, ears and neck. The backs of the hands are another common location. These areas are most often sun exposed on a chronic basis, particularly in men. People exposed to human papillomavirus may get cancers of the genital and anal skin.

With respect to the skin, basal cell carcinomas arise from the bottom layer of the epidermis, the basal cell layer. Growth of basal cell carcinomas is primarily confined to the local skin area. They rarely spread to other areas of the body (metastasize), but if left untreated, can cause damage to local structures. Invasion of adjacent bone is possible in untreated basal cell carcinomas. If resected, these cancers tend to recur in the same location as the original cancer, though new basal cells can occur in other locations of the body.

Squamous cell carcinomas also tend to invade local areas and can recur in the same location as an original lesion. They are more likely to spread to other areas of the skin, but tend not to spread through the lymph nodes. Squamous cell carcinomas arise from the more superficial layers of the skin.

Melanomas are found anywhere on the body, but most commonly on the upper back of men and women and the backs of legs of women. Unusual locations for melanomas include under the fingernail bed and in the retina of the eye. These cancers originate in the pigmented cells of the skin, called the melanocytes. Because of their cells of origin, melanomas are nearly always pigmented with a brown, black or bluish color.

Unlike non-melanotic skin cancers, melanoma is much more likely to spread to distant areas of the body. The cancer may extend to deeper layers of tissue like the other skin cancers. However, non-contiguous spread to other areas of the skin, termed “satellite lesions”, is common. Melanomas may also spread through the lymph nodes to distant parts of the body. Finally, metastases to the brain and distant organs is common in more advanced melanomas

Appearance and Characteristics

Basal cell carcinomas have a similar appearance to pale moles or are described as smooth, usually symmetric, wart-like bumps. They may be flesh coloured, pale or reddish, often with fine blood vessels visible. Occasionally, there may be ulceration of the basal cell carcinoma. A definite edge to the carcinoma is usually visible with stretching of the lesion.

Squamous cell carcinomas generally begin as flat areas of scaling and redness of the skin. Pre-cancerous lesions, called actinic keratoses, will have a hard white scale over a red base. The scale may be scratched off, but tends to recur in the same location. As squamous cell carcinomas grow, they tend to become a deeper red colour, increase in diameter and may develop central ulceration. The edge is less distinct than that of basal cell carcinomas. Squamous cell carcinomas may also develop a nodular appearance.

Melanomas are much more variable in appearance. The commonly used mnemonic for remembering melanoma appearance is “ABCDE”. “A” stands for “Asymmetry” represented by one side of the lesion not matching the other side. “B” represents “Borders” which are irregular and notched. “C” indicates that the “Color” is variable, often with multiple shades in the pigmented lesion. “C” may also stand for changing appearance or size. “D” represents “Diameter” of greater than 6 mm, or ¼ inch. “E” represents “Elevation” as most benign moles tend to be flat, melanomas will develop a raised surface.

The above distinguishing features are general guidelines only--of course, any suspicious skin lesion should be checked by your physician. Persons with large numbers of moles are at greater risk for melanoma and careful personal and professional examinations are important for early detection. For excellent photographs of each of these types of cancer, see the American Family Physician articles on “Early Detection and Treatment of Skin Cancer” and prevention and “Early Detection of Malignant Melanoma”.

Treatment

Skin cancers may be treated in several ways. The optimum treatment depends on the type of cancer, its depth and its circumference. Location of the cancer, particularly if on the face, and patient preference also are determining factors.

Basal cell carcinomas may be treated with cryotherapy (freezing), excisional biopsy (surgically removing the tumour) or by curettage (scooping out the cancer) with electrodessication (cauterization). Mohs micrographic surgery involves progressively shaving off layers of the tumour until microscopic analysis indicates that the deepest layers are tumour free. Other less common treatments involve oral medications, radiation therapy and lasers.

Squamous cell carcinomas are often preceded by pre-cancerous actinic keratoses (AKs) described above. AKs are usually frozen off with liquid nitrogen applied weekly for several weeks. A medication applied to the skin, called 5-FU, is often used on the face. Surgical excision is usually not necessary in early squamous cell carcinomas. When necessary, Mohs micrographic surgery is usually appropriate. More advanced lesions or those that have metastasized may require extensive surgery or chemotherapy. Metastatic squamous cell carcinomas only have a 34% 5-year survival rate.

Malignant melanomas are much more aggressive tumours that demand a wider range of treatments depending on the circumstances. The simplest treatment is excision, or surgical removal of the cancer. Generally, a wide margin of surrounding normal tissue is also removed to decrease the chances of leaving any microscopic melanoma cells.

In melanomas found on the fingers and toes, particularly those of deeper penetration, amputation of the finger or toe may give the patient the best chance of survival. Deeper lesions found anywhere on the body may dictate an extensive regional lymph node removal to determine the extent of spread and to decrease the risk of missing a metastatic “seed” in the lymph nodes.

If the melanoma has spread to a distant organ, usually the liver, lung or brain, the 5-year survival drops to 5%. Although surgical removal of the metastasis will not result in a cure, it may improve patient comfort and quality of life. Metastatic melanoma also can be treated with chemotherapy and radiation therapy, but survival is not significantly extended.

Immunotherapy is the newest form of routinely practiced treatment for advanced melanoma. Two types of immunotherapy include cytokine and vaccine therapy. Both of these treatments are designed to boost the individual’s immune system in an attempt to kill quickly growing melanoma cells. Cytokine therapy uses compounds called interferon-alpha and interleukin-2. A variety of antiviral vaccines may be used to stimulate the body’s immune system.

Clinical trials are being conducted at many research institutes to investigate experimental forms of therapy. One resource for information is the Clinical Trials Watch.

Prevention

The key to prevention is avoidance or protection from sun exposure and ultraviolet radiation. The most intense sun is found from 10 AM until 4 PM. Outdoor activities during these times should be minimized. People participating in outdoor activities during these times should consider wearing long sleeves and pants with sun glasses and a broad brimmed hat that shades not only the face, but also the ears and neck. This is especially true for sun exposures in lower latitudes and higher altitudes.

Ultraviolet Radiation and Skin Damage

When complete protection from the sun in the form of clothing or shade is not possible, sunscreen use provides the best protection from the damaging radiation from the sun that can cause skin cancers and premature aging. To be able to determine which sunscreen product is most appropriate, an understanding of the sun’s skin-damaging electromagnetic radiation spectrum is in order.

The ultraviolet (UV) portion of the sun’s electromagnetic spectrum causes damage to the skin. The UV portion is divided into the UVA and UVB, with the UVA being further divided into UVA I and the UVA II. The most damaging portion is the UVB, followed by UVA II and least damaging is UVA I. Skin damage and cancer is caused by damage to the DNA in skin cells. Changes in DNA are cumulative. DNA damage can lead to abnormal growth of cells which, over time, may cause cancer. This damage may also cause premature wrinkling and aging of the skin. The UV spectrum also stimulates the skin to produce more melanin from melanocytes. This dark coloured melanin is responsible for a tan. Tanning booth lamps give off large amounts of UVB radiation to give a quick tan.

Individual sensitivities to sun exposure varies, primarily with natural skin pigmentation. Medications and some medical conditions may temporarily increase an individual’s sensitivity. Sensitivity is quantified by noting the amount of redness, known as “erythema”, of the skin following an exposure to UV radiation. Sunburns are erythema of the more superficial skin cells, primarily caused by UVB radiation. The infrared (IR) spectrum gives the sensation of heat. Therefore, the perceived outside temperature plays no role in sunburn or tan, as evidenced by skiers getting severe face burns on very cold days.

Sunscreens

Sunscreens are designed to block the damaging UV radiation. The degree of protection is measured in units of SPF, or Sun Protection Factor. The SPF is measured by determining the multiple of time exposed to the skin to produce the same amount of erythema in unprotected skin. For example, if an individual gets a certain amount of erythema within 24 hours after 10 minutes of exposure to the sun, the same individual using an SPF 15 product could remain in the sun 150 minutes, or 2 hours and 30 minutes (15 times 10 minutes) to get the same amount of erythema.

SPF is only quantified for UVB radiation protection. UVA protection is difficult to measure because the UVA spectrum does not significantly contribute to erythema. The FDA will allow manufacturers to claim UVA protection if the product blocks any of the UVA II spectrum. Factors such as wind, water, perspiration and others may reduce the effective SPF. Insect repellents with DEET may reduce the effective SPF.

Sunscreens claim a broad range of SPFs, from 2 to 65. SPFs of higher than 30 have essentially no additional protective effect than an SPF of 30 does. An SPF of 15 only allows 6.4% of UVB to reach the skin, while an SPF of 30 allows 3.3% of UVB to penetrate. An SPF of 60 would only block another 1.7% of the UVB radiation.

New FDA recommendations may require a nominative scale of SPF ratings. A “Minimal” designation equates to SPFs of 2 to 11, a “Moderate” designation ranges from SPFs of 12 to 29 and SPFs of 30 or higher are termed “High”.

The June 2001 issue of Consumer Reports has an excellent article testing many features and prices of 23 different brand name sunscreens.

Sunscreen should be applied at least 20 minutes prior to sun exposure for maximal effectiveness. People tend not to apply sunscreen evenly to all areas of the skin. Therefore frequent applications provide more uniform protection. Exposure to water and towelling off reduces sunscreen protection. Reflective surfaces such as water, sand, snow and concrete will increase intensity of UV radiation. Clouds shield IR radiation and lower temperatures, but allow significant UV penetration. As a general rule, if a shadow is visible, UV radiation is reaching exposed skin.

Aircraft windscreens and canopies generally do not allow UV radiation to penetrate. Therefore pilots are not at risk for increased exposure to UV radiation when piloting an aircraft, although time spent on the tarmac certainly can be associated with exposure to harmful UVB radiation.

Tips for Reducing Risk from UVB

These tips are collected from a variety of sources noted in the references below.

1) Stay out of the sun between 10 AM and 4 PM

2) Use covering clothing, hats and sunglasses when outdoors

3) Use sunscreen of SPF 15 –30 that is water resistant

4) Be aware of reflected sunlight off water, sand, concrete and snow

5) Apply sunscreen at least 20 minutes before sun exposure

6) Reapply sunscreen often, particularly when exposed to water or perspiration

7) Avoid sun lamps and tanning booths

8) Read medication labels for possible skin sensitizing side effects

9) Don’t smoke

10) Protect yourself every time you are out in the sun

11) Protect children from intense sun exposure as they are at highest risk


FAA Policy on Melanoma and Skin Cancer

Pilots and controllers with a diagnosis of skin cancer may not fly or control until the cancer is removed. Those with basal cell carcinomas and squamous cell carcinomas may return to aviation duties after surgery which completely removes the cancer and treatment is complete. Controllers will need to obtain specific Regional Flight Surgeon clearance before returning to controlling. For pilots, reporting to the FAA may be accomplished at the time of the next medical application on FAA Form 8500-8. Pilots are advised to bring documentation from their treating physician regarding the cancer to their AME. Those rare basal cell and squamous cell carcinomas that can not be completely resected, require ongoing therapy or that have metastasized are disqualifying for flight duties until the medical documentation has been reviewed and cleared by the FAA.

Melanomas are disqualifying for aviation duties. The length of disqualification depends on the depth and stage of the melanoma. Pilots/controllers with melanomas may have their cases reviewed by the FAA for return to flying/controlling as soon as treatment is complete, if there is no evidence of metastasis or if metastases are confined to regional lymph nodes until treatment is complete. Metastases to distant organs (besides the brain) are disqualifying for a minimum of three years following completion of treatment. Brain metastases disqualify an individual for at least five years following completion of treatment. Each of these cases requires reporting and clearance by the FAA before returning to flying or controlling. A Special Issuance Authorization will be issued to pilots cleared to fly after more extensive melanomas are diagnosed and successfully treated. Controllers would receive a Special Consideration to return to safety sensitive duty.