Observation is the best medicine for choroidal lesions

Nancy Groves

Outcomes from a long-term study of patients with small, suspicious choroidal melanoma suggest that observation is an effective strategy that is associated with very low melanoma-specific mortality rates and preservation of visual acuity.

Key Points

The study's melanoma-specific mortality rate of 0.7% over 10 years indicates that observation is safe when patients are watched closely for signs of change in their tumors, said Timothy G. Murray, MD, FACS, here at the annual meeting of the Retina Society.

Dr. Murray presented findings from a long-term study of patients with small choroidal melanoma, noting that the best approach to small, suspicious pigmented lesions has been a controversial subject for years. He is professor of ophthalmology with a secondary appointment in radiation oncology at the Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami.

"The majority of the patients had tumors that did not change, [and] . . . the patients didn't die from their tumors," Dr. Murray said. "This was the pivot point that changed how everybody thought about these smaller, presumed-malignant melanomas."

The Collaborative Ocular Melanoma Study (COMS) then was launched with an observational component for small tumors (1 to 3 mm in apical height and 5 to 16 mm in largest basal dimension). The study of 204 patients noted a 5-year tumor growth rate of 31% and a melanoma-specific mortality rate of 1%.

"Because those data were available to us, they suggested to me, as director of the ocular oncology service at Bascom Palmer, that a reasonable thing to do for patients with small tumors is bring them in and, if appropriate, watch them initially and not to treat them as having cancer until there is a change that suggests that the lesion is cancerous," Dr. Murray said.

Cohort followed

He and colleagues at Bascom Palmer then organized a study to follow a prospective cohort of patients undergoing plaque radiotherapy with iodine-125 after initial observation for documentation of growth in small choroidal melanomas. Patients were eligible if their tumors were 1.5 to 2.5 mm thick with a base of 5 to 16 mm and had a risk factor such as orange pigmentation or subretinal fluid.

Patients were seen every 4 months, and their tumors were documented with special high-resolution ultrasound and photography. The study enrolled 154 patients; 45 had tumor growth over the follow-up period, which was a minimum of 5 years for all patients.

Among the 109 whose tumors did not grow over the observation period, which for some patients was up to 15 years, no melanoma-related deaths occurred.

"If you watch someone with one of these high-risk tumors and the tumor doesn't change, they have essentially no risk of dying from the tumor," Dr. Murray said.

He also reported the outcomes of the 45 patients whose tumors had changed during the observation period. Only one patient died over a 10-year period from a tumor that had spread, resulting in a 2% melanoma-specific mortality rate. Another patient's tumor had metastasized, but the patient still was alive at the end of the 10-year period.

"What that suggested was that, if you looked at the entire 154 patients, the 10-year melanoma-specific mortality was approximately 1%, and in the group of patients whose tumors grew, the melanoma-specific mortality was 2%," Dr. Murray explained.