Merkel Cell Carcinoma Causes

There are several potential causes of Merkel cell carcinoma. As with other skin cancers, most Merkel cell carcinomas develop in areas of skin that are frequently exposed to ultraviolet (UV) light. As such, exposure to sunlight – both natural and artificial (via tanning beds) -- is thought to be a potential trigger. It’s well established that UV radiation can cause substantial damage to skin cells, although researchers are still attempting to identify the pathway through which the damaged cells become cancerous.

Another potential cause of Merkel cell carcinoma is infection with the Merkel cell polyomavirus (MCPyV). This virus has been found in more than 80 percent of all Merkel cell carcinomas. However, many adults carry MCPyV and never develop cancer (or any other health problems); researchers are still working to identify the precise connection between the virus and the development of Merkel cell carcinoma. The leading theory is that MCPyV causes genetic mutations that – when the body’s immune system is compromised – can eventually cause certain skin cells to become cancerous.

While researchers are still investigating the exact causes of Merkel cell carcinoma, it is generally understood that:

  • All cells are programmed with instructions to grow at a specific rate and to die when their life cycles are complete.
  • When the DNA of a healthy cell becomes damaged, that cell may lose its ability to replicate in a controlled manner.
  • A damaged cell can produce copies of itself, leading to small clusters of abnormally functioning cells (tumors).
  • These tumors can potentially invade the surrounding cells. In the case of Merkel cell carcinoma, this growth often happens quickly. At the time of diagnosis, many Merkel cell carcinomas are found to have spread to surrounding tissues. 

Skin cancer research is one of the leading areas of focus at Moffitt Cancer Center. We are home to a designated team of clinicians, lab workers and epidemiologists (public health professionals who study the causes of cancer). Our research team works tirelessly to learn more about skin cancer each day, in turn providing our physicians with an expanding knowledge base that improves outcomes and quality of life factors for our patients.

Additional information about Merkel cell carcinoma causes can be provided by our expert oncologists. Referrals are not required to make an appointment; call 1-888-663-3488 or submit a new patient registration form online.