Radiation treatment can help reduce the recurrence of Merkel cell carcinoma, while chemotherapy does not appear to have any impact on recurrence or survival, according to a new study published online in JAMA Dermatology.

May is Skin Cancer Awareness Month.

The new study presents one of the largest single-institution datasets on Merkel cell carcinoma, which occurs in about 1,500 people in the United States annually. Most cancers occur on the sun-exposed skin of white males and are first diagnosed at age 75, on average.

“If it is caught early, Merkel cell carcinoma has an excellent prognosis and cure rate, but if it spreads, it can be deadly,” says Maryam M. Asgari, MD, MPH, of the Kaiser Permanente Division of Research in Oakland, Calif.

Of 218 cases of Merkel cell carcinoma, those patients who had radiation treatment had a 70 percent lower risk of disease recurrence while chemotherapy did not appear to have any impact on recurrence or survival, the study showed.

Researchers used Kaiser’s electronic health record system, Kaiser Permanente HealthConnect® to evaluate the relationships between cancer recurrence and survival with demographic information (age, sex, race, immunosuppression) and tumor characteristics (extent, size and location), as well as cancer work-ups (pathologic lymph node evaluation, imaging) and treatments (surgery, radiation and chemotherapy).

Immunosuppression and more advanced tumors were associated with worse survival rates related to Merkel cell carcinoma, and that pathological evaluation of the patient’s lymph nodes also had a significant impact on outcomes, the study showed.

Of note, tumors in which the primary cancer was unknown were associated with a decreased risk of mortality, Asgari says. “You may think this is a terrible scenario, but we found the reverse. These individuals had better survival.”