WAIKOLOA, HAWAII - Melanomas are more likely to be fatal when they occur in patients with a history of nonmelanoma skin cancer.
"All those patients we're seeing with squamous cell carcinomas or basal cell carcinomas that later develop melanoma do have an increased risk of developing metastatic disease, and of doing so early," Dr. James M. Grichnik (photographed on the left) said at the annual Hawaii Dermatology Seminar sponsored by Skin Disease Education Foundation.
He cited a recent University of Pennsylvania nested case-control study involving 549 patients who presented with nonmetastatic melanoma and subsequently developed metastatic disease at least 6 months after definitive surgery. Each of the patients was matched to a control subject who had melanoma that did not metastasize.
The study identified two novel risk factors for melanoma metastasis: prior nonmelanoma skin cancer and a history of malignancy other than skin cancer. In a multivariate, logistic, regression analysis adjusted for 34 variables, a past medical history of nonmelanoma skin cancer was independently associated with a 2.89-fold increased risk of metastasis. Prior cancer at a non-cutaneous site conferred a 3.68-fold increased risk.
Previously established risk factors for melanoma metastasis were reaffirmed in this study. For example, tumor ulceration was associated with a 2.85-fold increased risk, male gender had a 1.8-fold risk, a vertical growth phase tumor had a 7.67-fold risk, and the presence of microscopic satellites was associated with a 6.62-fold increased risk of metastasis, noted Dr. Grichnik, professor of dermatology at the University of Miami and director of the melanoma program at the Sylvester Comprehensive Cancer Center.
Early metastases, defined as being diagnosed within 3 years after definitive surgery, developed in 320 melanoma patients. Another 70 patients developed late metastases, arising 8 years or more post-surgery. The strongest predictor of early, as compared to late, metastasis was a history of non-melanoma skin cancer, with a 4.83-fold increased risk. Patients with early metastasis were also significantly more likely to have ulcerated lesions and thicker tumors (Cancer 2010;116:415-23).
Also useful in identifying aggressive melanomas are the American Joint Committee on Cancer Staging criteria, based largely on tumor thickness, nodal involvement, and metastases, Dr. Grichnik said. Other factors worth considering include tumor mitotic rate, the presence or absence of circulating tumor cells, and molecular marker status.
Dr. Grichnik disclosed having financial relationships with DigitalDerm Inc., Spectral Image Inc., and Electro-Optical Sciences.
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