WEDNESDAY, Aug. 12 (HealthDay News) -- Increasing tumor thickness of uveal melanoma is associated with a higher risk of metastasis and therefore may be an important indicator for patient prognosis, according to data published in the August issue of the Archives of Ophthalmology.
Carol L. Shields, M.D., of Thomas Jefferson University in Philadelphia, and colleagues performed a retrospective record review of patients diagnosed with uveal melanoma. Tumor thickness was measured as the distance of the posterior tumor margin to the optic disc margin and foveola.
The researchers found that the 10-year incidence of metastasis increased with increasing tumor thickness, from 6 percent for tumors between 0 to 1.0 mm thick to 51 percent for tumors over 10.0 mm thick. Increasing tumor diameter and tumor thickness were each found to predict metastasis in multivariate analysis, as were other clinical factors. At the 10-year follow-up, the authors note that the incidence of metastasis was 12, 26, and 49 percent in patients with small (0 to 3.0 mm), medium (3.1 to 8.0 mm), and large (>8.0 mm) melanoma, respectively.
"These data are applicable for the practicing clinician in that they are simple and useful in the clinic setting," Shields and colleagues conclude. "Knowledge of the approximate risk for melanoma-related metastasis based on accurate measurement of thickness and the added risk of each millimeter of thickness could ultimately affect the therapeutic decision."