Melanoma survivors at higher risk of other cancers

Melanoma survivors are at increased risk of other cancers as well as the return of their skin cancers, according to a new study, leading National Cancer Institute researchers to urge lifelong follow-up of such survivors.

The study included data from more than 89,500 patients collected from 1973 to 2006. There were 12,559 subsequent cancers, including 3,094 melanomas.

While not the most common form of skin cancer, melanoma is the most serious and most likely to be fatal. The American Cancer Society estimates that 68,720 Americans were diagnosed in 2009 with melanoma and that 6,850 Americans died from the disease.

Noting that most people with melanoma - more than 92 percent of white women, and nearly 87 percent of white men - survive at least 5 years after diagnosis, Dr. Portia T. Bradford and colleagues wanted to measure the risks of the disease coming back or of survivors developing a second melanoma or another type of cancer.

"The risk of subsequent cancer is important for melanoma survivors," they write in the March issue of the Archives of Dermatology.

Analyzing data collected by the Surveillance, Epidemiology, and End Results (SEER) program, they concluded that survivors had a 28 percent increased risk of a second cancer, mostly due to their 9-times greater likelihood of developing another melanoma than the general population. The most common second cancers after melanoma were breast, prostate, and non-Hodgkin's lymphoma.

Over the span of the study, doctors diagnosed 1,156 female breast cancers, 2,200 prostate cancers and 481 non-Hodgkin's lymphomas among the more than 89,000 melanoma survivors. In each case, the number of secondary cancers reported among survivors was higher than what would have been expected in the general population.

The risks of a second cancer were highest within the first year and declined somewhat over time but "remained quite elevated more than 20 years" after the first diagnosis.

Despite high survival rates for melanoma, there's no international consensus on how melanoma survivors should be followed-up.

The National Comprehensive Cancer Network, an alliance of 21 cancer centers and a respected authority on cancer practice guidelines, acknowledges that there's a wide variety of opinions about what a melanoma survivor follow-up program should look like - how long and how often survivors should be screened.

Because of the costs involved and the lack of clear data, "the optimal duration of follow-up remains controversial," they write in the 2010 version of the NCCN's melanoma practice guidelines.

Guidelines recommend exams more than once a year for anywhere from two to ten years, but they are often vague on what to do after that time. The NCCN recommends lifelong followup, but their guidelines are currently under review.