Recurrent melanoma is more common than previously thought, with nearly 15 percent of people diagnosed with the potentially fatal skin cancer at risk of a second diagnosis within two years, a new study found.
About 6 percent of patients will develop a second melanoma within one year of the initial diagnosis, while 8 percent will be diagnosed with a second malignancy within two years, according to the researchers from Dartmouth Medical School in Hanover, N.H.
This rate is more frequent than previously thought and points to the importance of surveillance and skin screenings, according to the study in the April issue of Archives of Dermatology.
According to the new study, previous studies have put melanoma recurrence at less than 4 percent within one year.
The current study included 354 New Hampshire residents who'd had a previous diagnosis of melanoma. All participants answered questions about their medical history, sun exposure history, hair and eye color, and whether their skin tanned, burned or freckled in the sun. Then they underwent a skin examination by a physician.
Six percent of the participants developed an additional melanoma within one year of the first diagnosis, while 8 percent developed an additional melanoma within two years.
Roughly two-thirds of those who developed additional malignancies and 37 percent of those who did not had at least one atypical mole, which is a risk factor for additional melanomas. Someone with three or more atypical moles had four times the risk of developing an additional tumor. Atypical moles have at least three of the following features -- a diameter larger than 5 millimeters; redness; an irregular or ill-defined border; a variety of colors or a portion that is flat, the researchers said.
In one-third of the patients who developed another melanoma within two years, the subsequent melanoma was deeper than the first.