As a Mohs surgeon, my primary job is treating the three most common skin cancers – basal cell carcinoma, squamous cell carcinoma, and melanoma. Squamous cell carcinoma (SCC) is the skin cancer that often causes the most confusion, partially because it shares the name “squamous cell” with other squamous cell cancers that do not arise from the skin. Recently, patients have asked questions about cutaneous (skin-derived) SCC, and their questions and answers are worth repeating given how common this cancer is and how many readers are likely either affected by it or have a loved one with cutaneous SCC.
1. Q: Is squamous cell of the skin the same as squamous cell of the lung?
A: No, SCC of the skin and SCC of the lung are not directly related. The reason that they share the word “squamous” is because in both locations, these epithelial cells look similar under the microscope. Cells in these locations overlap one another similar to how scales of a fish or shingles on a roof overlap, and “squama” is latin for scale. SCC of the skin and lung differ markedly in terms of what causes cancer (for example, ultraviolet damage vs smoking), how they are treated, and prognosis.
2. Q: Why, then are cells growing in such a similar fashion in the skin and the lungs?
A: In both locations, squamous cells come in contact with air, and the overlapping design of squamous cells allows them to decrease evaporative water loss and protect underlying tissue from damage caused by outside air or irritants. In the case of the lungs, the “outside” air happens to be inside our bodies while we breath, but the same principle applies. Squamous cells offer protection and a more limited exchange of “outside” influences with deeper body tissues.
3. Q: Is squamous cell of the skin as serious as squamous cell of the lung?
A: In general, no. Because SCC of the skin arises on the skin, we usually notice it when it is not advanced, and patients and dermatologists can typically catch SCC of the skin very early. Approximately 1 million SCCs of the skin are diagnosed each year, and only about 15,000 deaths occur. In contrast, about 25-30% of lung cancers in the US are squamous cell carcinoma. According to cancer.org, there will be about 225,000 new cases of lung cancer in 2019 and about 140,000 deaths.
Mohs surgery for squamous cell carcinoma of the skin offers a higher than 99% cure rate for small squamous cell carcinomas. Often, the squamous cell carcinomas of the skin that result in death are either long-neglected and allowed to grow or occur in an immunocompromised patient such as a transplant patient who may have an SCC grow so quickly that it is able to spread before it is eliminated.
4. Q: Are there other treatments besides Mohs surgery for squamous cell of the skin?
A: Yes, for a shallow SCC called “squamous cell carcinoma in situ”, patient may often choose between Mohs surgery, a wide excision and even topical creams. Invasive squamous cell carcinoma is often best treated with either surgery or radiation. If an SCC has already spread, a multidisciplinary approach including chemotherapy and/or radiation may be necessary and will require the assistance of an oncologist.
If you or a loved one has sun-damaged skin or a history of squamous cell carcinoma (of the skin), consider Premier Dermatology and Mohs Surgery of Atlanta for your skin care needs. Dr. Brent Taylor is a fellowship-trained Mohs surgeon and board certified dermatologist offering state-of-the-art skin cancer treatments and care.
At Premier Dermatology and Mohs Surgery of Atlanta, it is our pleasure to meet your skin care needs. Board certified and fellowship-trained, Dr. Brent Taylor is a skin cancer, vein and aesthetic expert honored to be of service.