As daylight's savings brings more daylight into our lives, it's a good time to start thinking about protecting your skin from the sun's rays. Though most people have heard of melanoma, and some have heard of basal cell cancer, fewer have heard of squamous cell cancer. But it's an important cancer to know aboutâ€”it's three times as common as melanoma (some 200,000 new cases each year versus 62,000) and squamous cell is more serious than basal cell because it is likely to spread (metastasize).As you'll see when you read the article below, first printed in Harvard Women's Health Watch, there is some good news about squamous cancerâ€”it can be cured much of the time. Interestingly, while most of these cancers arise on sun exposed portions of the skin, squamous cancers can also arise in other portions that are generally covered by clothes, such as the female genital labial area, the penis and scrotum in a male, and the skin surrounding the anal area and anus itself. Many of these latter type of squamous cancer can be associated with infections with viruses, such as the well know HPV (Human papilloma virus). Thus, the emphasis here is to recognize any skin abnormality as potentially being a cancer and seeking attention of a medical professional if there are new abnormalities or persistent ones.Â For the cancer that arise on the skin, prevention is important.
Treated early, the cure rate is over 90%, but metastases occur in 1%â€“5% of cases. After it has metastasized, it's very difficult to treat. Now, here's the article from Harvard Women's Health Watch.What it looks like
Squamous cell cancer involves the runaway growth of keratinocytes, cells in the outermost layer of skin, which produce the protein keratin. Squamous means scaly; in 60%â€“80% of cases, the lesions emerge on or near scaly patches called actinic keratoses that develop from sun-damaged skin.
Typically, such lesions are hard (from the keratin), well-defined, and occasionally crusty. Some you might mistake for a wart, only flatter. And there are those that are soft and fleshy. You can see examples of squamous cell carcinomas on the Medline website from the National Institutes of Health.Risk factors
Exposure to sunlight is the main risk factor for skin cancer. For melanoma, sporadic instances of intense exposure seem to be triggers. For squamous cell cancer, cumulative exposure and possibly the intensity of the sunlight may be more significant. As with all skin cancers, skin color is relevant; those with darker skin (African Americans, Africans, Asians) have lower rates of squamous cell cancer than Caucasiansâ€”and among Caucasians, lighter-skinned people are more vulnerable.
Organ transplant recipients are especially vulnerable to squamous cell cancer. European research suggests that heart and kidney recipients are 65â€“250 times more likely to get squamous cell cancer than the general population. The most likely explanation is that the drugs that transplant patients take to suppress their immune systems and prevent organ rejection also make them vulnerable to this skin cancer. A history of sun exposure before or after the transplant heightens the risk.
Chronic inflammation is another risk factor. The squamous cell skin cancers sometimes emerge from chronically inflamed scars or sores.Treatment
Treatments for squamous cell cancer all have the same goal: Get rid of the cancer cells, while avoiding unnecessary harm to surrounding skin.
Cryotherapy (rapid freezing) and radiation are used if the lesion is small and not likely to metastasize. Cryotherapy is fast and inexpensive but can leave a whitish mark. Radiation gives the doctor pinpoint control, minimizing damage to healthy skin, but it's expensive, involves many visits, and could result in a more aggressive case if the cancer recurs. Ointments are useful if there are many lesions but can cause stinging, burning, and oozing.
Surgery is the main therapy for larger lesions, and Mohs surgery is becoming the standard, especially for lesions on the face, where cosmetic results matter. Dr. Frederic Mohs, of the University of Wisconsin, developed the procedure during the 1930s and '40s. It involves shaving thin, horizontal slices from the lesion and microscopically examining each one for cancer cells.
This cut-examine-cut-examine technique has two advantages. First, it takes the guesswork out of how deep to cut, so the surgeon is less likely to remove healthy tissue while operating. Second, it's less likely to leave cancer cells behind, which may explain why it tends to have a higher cure rate than other techniques.
Drawbacks include cost and time. It's done on an outpatient basis, and patients may spend hours waiting while the surgeon inspects each slice. Some doctors believe the technique may be overused and should be restricted to high-risk or cosmetically sensitive lesions.Prevention
Sun safety is fairly straightforward. Avoid being outdoors between 11 a.m. and 4 p.m., when the sun is most intense. Remember that exposure doesn't just happen at the beach. By some estimates 80% of it is incidental to everyday activities like walking the dog, running errands, and so on. Noses, ears, and necks are especially vulnerable, so wear a wide-brimmed hat. A baseball cap offers no protection to your ears and neck (or, if it's worn backwards, your nose and face).
Sunscreen isn't a magic shield. The National Cancer Institute (NCI) says the evidence that it prevents squamous cell skin cancer is only "fair." (For basal cell cancer and melanoma, the NCI says there is inadequate evidence to know if sunscreen is preventive.) In fact, some argue that by preventing sunburn, sunscreens offer a false sense of security, encouraging people to stay in the sun too long. Sunscreen users should buy one with a sun protection factor (SPF) of at least 15. Be sure to put on enough lotion. You need almost three tablespoonfuls on your face, neck, arms, trunk, and legs per application. At least a teaspoon should go on your face and neck.
What do you do to protect yourself from skin cancer?
Marc Garnick, M.D., is an internationally renowned expert in medical oncology and urologic cancer, with a special emphasis on prostate cancer. He is a Clinical Professor of Medicine at Harvard Medical School and maintains an active oncology practice at Beth Israel Deaconess Medical Center. Dr. Garnick serves as Editor in Chief of Perspectives on Prostate Diseases, a quarterly report from Harvard Health Publications.
Time and sun are tough on your skin, and troublesome skin conditions can set in at any age. But skin treatments have changed dramatically in recent years. Skin Care and Repair, a special report from Harvard Medical School, explains the latest high-tech solutions and drug regimens available to control both cosmetic and medical skin problemsâ€”from age-related wrinkles to life-threatening cancers.