In March of 2023, it was reported that President Biden was found to have a skin lesion on his chest during his annual physical exam at Walter Reed Medical Center. A biopsy showed that it was a type known as a basal cell carcinoma, and it was successfully removed. The press report regarding this lesion indicated that he had a history of several such lesions several years ago. In January 2023, three basal cell carcinomas were removed from Jill Biden, one from her chest, one from above her left eye, and one from her left eyelid. I am not aware of whether there are any skin malignancies among any of the Republican presidential candidates.
OK, it is Final Jeopardy again, and the Final Jeopardy answer is, “The most frequently diagnosed cancer.” I guess if you are following the drift of this article, you will have a clue. The correct question is, “What is skin cancer?” To some degree, this reflects the fact that the skin is the largest organ in the body. But it also reflects the fact that the skin is our external barrier to the universe, and thus exposed to all the toxins and environmental exposures that this position makes possible.
The most obvious and important exposure that falls into this category is exposure to ultraviolet radiation from the sun. The risk of skin cancer is a function of the cumulative exposure to this radiation; this radiation causes DNA damage that leads to carcinogenesis. Those who utilize indoor tanning in place of actual sun exposure are still subject to increased risks of skin cancer. Of course, in current times, much of sun exposure, especially for urban dwellers, is limited to recreational activities, but many occupations involve outdoor work—agriculture, construction, maritime, and the like. And it should not take much mental effort to appreciate that sun exposure is also a function of latitude—skin cancer rates rise dramatically as one’s residence moves south and closer to the equator.
The rates are significantly higher in males than females. The occurrence of the disease is also a function of the skin pigmentation of the individual, with higher rates in fair-skinned populations from Northern Europe—Celts and Scandinavians in particular—and lower rates in those of African descent. For example, the annual incidence rate of cutaneous squamous cell carcinoma in non-Hispanic Whites in the U.S. is approximately 150/100,000 for females and 360/100,000 for males, respectively, while the rate for Blacks is 3/100,000. In those with fair skin, these malignancies tend to occur on sun-exposed parts of the body—the face, neck, back of the hands. Furthermore, these cancers are age-dependent, occurring primarily in the elderly, like the Bidens.
For the type of skin cancer known as basal cell carcinoma and for melanomas, intense intermittent sun exposure is the most important risk factor, Thus, the frequency of sunburns and extensive childhood exposure correlate with the risk. Meanwhile, for cutaneous squamous cell carcinoma, chronic cumulative sun exposure, as in occupational exposures, is the most common cause of these cancers.
There are certainly other risk factors as well. Arsenic exposure, ionizing radiation, family history, immunosuppression, a history of an organ transplant, all increase risk. There are certain genetic syndromes that also can place an individual at increased risk.
I hope that the reader is obtaining the impression that prevention is an important and key possibility for skin cancer. There are three major types of skin cancer to which we have already alluded—melanoma, the most dangerous and fatal of the three, and the non-melanotic skin cancers, basal cell and squamous cell.
The most common of the three types of skin cancer is basal cell carcinoma. It can be a flesh-colored or pearl-like bump on the skin and, while most common on the head, neck and arms, can occur anywhere on the body. Squamous cell carcinomas are more likely to look like scaling patches or spots on the skin, sometimes referred to as actinic keratoses or progress from these precursor lesions. They almost always occur on sun-exposed surfaces—the neck, face, rim or pinna of the ear, back of the hands or arms, chest and back. Melanoma, the most serious type of skin cancer, usually looks like a dark spot, and can arise in pre-existing moles.
The non-melanotic skin cancers—basal cell and squamous cell—can metastasize, but only rarely do so. However, they can penetrate deeply and be disfiguring if not treated and removed. Surgery for non-melanotic skin cancers is usually curative.
Once someone has had such a malignancy, they are at significantly increased risk of developing a new tumor. Thus, they do need to continue under the care of a dermatologist or some other health care professional for surveillance. But it is worth reiterating that these tumors are generally quite age-dependent. And prevention by limiting exposure to UV radiation should be the primary approach for these tumors.
Over 5 million non-melanotic skin cancers are treated annually in the U.S.
Alfred I. Neugut, MD, PhD, is a medical oncologist and cancer epidemiologist at Columbia University Irving Medical Center/New York Presbyterian and Mailman School of Public Health in New York. Email: [email protected].
This article is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment, and does not constitute medical or other professional advice. Always seek the advice of your qualified health provider with any questions you may have regarding a medical condition or treatment.