Abstract
Purpose: :
To develop objective inclusion criteria for a randomized clinical trial of prompt treatment vs deferred treatment for small choroidal melanoma.
Methods: :
Data from the small melanoma prospective study component of the Collaborative Ocular Melanoma Study were used for this supplemental analysis. Multivariable analysis of features associated with time to growth was performed in a stratified manner. Growth was defined as an increase from small to either medium or large-sized melanoma. Kaplan-Meier estimates of time to growth to medium or large tumor size were calculated for all subgroups of patients specified by their cumulative number of baseline risk factors (1 through 5); 5-year estimates and their corresponding 95% confidence intervals were obtained and compared.
Results: :
Forty-four tumors grew during follow-up. Growth was defined as an increase from small to either medium or large-sized melanoma. Various combinations of risk factors were observed in the 188 tumors; any two risk factors were present in 179 tumors (95.2%) and none had all five factors. The risk of growth at 5 years was more than 50% when the tumor was either large (diameter 12.1-16.0 mm) or when orange pigment was present. Tumor thickness (2.0 mm-3.0 mm) by itself was not associated with increased growth rate but appeared to be significant when such tumors were larger in diameter (12.1-16.0 mm) or had orange pigment.
Conclusions: :
Since the risk of tumor growth in patients with high risk factors (50% or greater rate of growth by Kaplan-Meier estimate) exceeds the risk of non-growth, it is ethical to randomize such patients into an intervention trial.
Keywords: oncology • melanoma • uvea