The cause of Merkel cell carcinoma is unknown, according to Mayo Clinic. However, there are some things that raise a person's risk for this aggressive skin cancer, according to the American Cancer Society.
Merkel cell carcinoma is probably not hereditary, says the American Cancer Society. However, long-term exposure to ultraviolet radiation damages the DNA found in the skin. People are exposed to UV radiation by being out in the sun, from light therapy that helps treat psoriasis and from tanning beds.
People with a Merkel cell polyomavirus, or MCV, infection also seem to be at higher risk for developing Merkel cell carcinoma, says the American Cancer Society. However, MCV itself is still rather mysterious. It is a common virus, but most people who have it do not go on to develop Merkel cell carcinoma.
Other factors that put a person at higher risk for developing Merkel cell carcinoma are being light-skinned, older, male and having an immune system that is compromised, claims the American Cancer Society. People who have HIV, or people who've had organ transplants have weakened immune systems. In the case of organ transplant recipients, the immune system is deliberately weakened to lower the risk of rejection. Patients with leukemia and lymphomas also have weakened immunity and may be at greater risk from Merkel cell carcinoma.