We often associate skin cancer with the sun, and assume that we can only develop it on areas that receive the most sun exposure. However, skin cancer can develop anywhere on the body, including the feet.
Unfortunately, the skin of the feet is often overlooked, which is why checking the feet regularly for changes is so important. Skin cancers of the feet can be a little different than on other parts of the body – and even from each other. Most are painless. There is often a history of recurrent cracking, bleeding, or ulceration.
Skin cancers of the feet are often related to viruses such as human papilloma virus (HPV) and herpes; exposure to chemicals like arsenic, industrial tar, coal, paraffin and certain types of oil; chronic inflammation or irritation; or even genetics; according to the Skin Cancer Foundation, about 10% of people diagnosed with melanoma have a family member who has had melanoma at some point in their lifetime.
While malignant melanomas make up only 1% of skin cancers, they account for over 60% of skin cancer deaths. It is estimated that approximately 30% of melanomas occur in the lower extremities, and that 3% occur in the feet.
And melanomas are the most serious type of skin cancer. They commonly begin as a small brown-black spot or bump; however, roughly one third of cases lack brown pigment and thus appear pink or red. Melanomas may resemble benign moles, blood blisters, ingrown nails, plantar warts, ulcers caused by poor circulation, foreign bodies, or bruises.
Treatment of a melanoma can again involve a number of procedures, depending upon when it is detected. Caught early, it can be removed during an office visit. If the case is more advanced, radiation therapy, chemotherapy, or immunotherapy (which stimulates the immune system to attack cancer cells) may be involved.
I had a patient about 10 years ago who had seen multiple doctors for what they thought was a chronic infected ingrown toenail of his first toe. He came to see me as a consult for the same condition. I scheduled him for a biopsy and it was positive for malignant melanoma that had spread to the bone. He ended up having his first toe amputated. He was lucky that it hadn’t spread any further.
I should also mention the two other most common types of cancers affecting the skin of the feet:
Basal Cell Carcinoma: The most frequently seen type of skin cancer, this appears on sun-exposed areas as a smooth, raised bump or a sore that is not healing. It rarely metastasizes or causes death because it grows slowly and seldom spreads. It is easily treated with surgery or radiation.
Squamous Cell Carcinoma: This appears on sun-exposed areas as thick, red, scaly patches or as a bleeding ulcer. It is more serious than basal cell carcinoma because, in some instances, it may spread to other areas of the body. Radiation therapy, scraping away the cancerous tissue, or a variety of surgeries may be recommended.
Of course, overexposing your feet to the sun can also have a negative effect. Prevention of skin cancer on the feet is similar to any other body part:
- Limit sun exposure.
- Make sure to apply appropriate sunscreen when you are outdoors to your feet and ankles. Make sure to reapply sunscreen after swimming.
- Examine your feet regularly for any skin changes.
- Notify your doctor immediately if you notice any changes to your skin.
Taking care of your feet is as important as doing so with the rest of your body. If you suspect you may have developed a skin cancer on your foot, see a podiatrist as soon as possible.