FACTORS PREDICTIVE OF GROWTH AND TREATMENT OF SMALL CHOROIDAL MELANOMA - COMS REPORT NO-5

Objectives: To describe time to tumor growth of a prospectively follow ed group of patients with small choroidal melanoma and to determine ba seline clinical and photographic characteristics associated with lime to growth. Methods: The Collaborative Ocular Melanoma Study (COMS) is a set of clinical trials designed to compare radiotherapy and enucleat ion in the treatment of medium- and large-size choroidal melanoma. Fro m December 1986 to August 1989, patients with small choroidal melanoma , not large enough to be eligible for the COMS clinical trials, were o ffered participation in a nonrandomized prospective follow-up study. S mall choroidal melanomas were defined as 1.0 to 3.0 mm in apical heigh t and 5.0 to 16.0 mm in largest basal dimension. A total of 204 patien ts were enrolled in the study and were followed up annually through Au gust 1989. An assessment of current size of tumor, treatment status, a nd vital status was conducted in 1993-1994; an additional assessment o f treatment and vital status was performed in 1995-1996. Results: Of 1 88 small tumors not treated at the time of study enrollment. 46 grew d uring follow-up to a size that was large enough to be eligible for the COMS clinical trials. The Kaplan-Meier estimates of proportion of tum ors that grew were 21% (95% confidence interval, 14%-27%) by 2 years a nd 31% (95% confidence interval, 23%-39%) by 5 years. Factors signific antly associated with time to growth in a Cox proportional hazards reg ression model were greater initial tumor thickness and diameter, prese nce of orange pigment, absence of drusen, and absence of areas of reti nal pigment epithelial changes adjacent to the tumor. Conclusions: Of small choroidal melanomas initially managed by observation. 21% demons trated growth by 2 years and 31% by 5 years. The clinical and photogra phic features of these tumors confirm previous findings and are useful in identifying patients with small tumors at highest risk of short-te rm growth.