The COMS randomized trial of iodine 125 brachytherapy for choroidal melanoma, II: Characteristics of patients enrolled and not enrolled

To describe characteristics of patients evaluated for the Collaborative Ocu lar Melanoma Study (COMS) randomized clinical trial of iodine 125 brachythe rapy for choroidal melanoma by enrollment status, and to compare characteri stics of patients enrolled with those of patients with turners of eligible size who did not enroll in order to assess the extent to which findings fro m the clinical trial can be generalized to future patients. Methods: For all patients diagnosed with choroidal melanoma and evaluated f or the clinical trial at COMS centers from November 1986 through July 31, 1 998, selected data were transmitted to the COMS Coordinating Center, Baltim ore, Md, where they were integrated and analyzed. Data included ophthalmic and medical history, examination findings, and visual acuity measurements r ecorded prior to enrollment; standardized A- and B-scan echographic examina tion findings; and wide-angle fundus photographs and fluorescein angiograms . Results: Of 8712 patients with choroidal melanoma, 5046 had turners of elig ible size; of these, 2882 (57%) were eligible for enrollment, and 1317 (46% of eligible patients, 26% of patients with tumors of eligible size) enroll ed. Most differences between eligible and ineligible patients corresponded to eligibility and exclusion criteria. However, ineligible patients were ol der and had thicker tumors than eligible patients. Eligible patients who en rolled were slightly older and had larger tumors than those who did not enr oll. Nearly half (48%) of enrolled patients had choroidal melanoma with the apex located temporal to the fovea, compared with 40% of eligible patients not enrolled and 29% of ineligible patients. Conclusions: This trial was designed to yield internally valid treatment co mparisons through random assignment to treatment at time of enrollment. Inf ormation from this and other studies document that enrolled patients were s imilar to other patients with choroidal melanoma who were treated with I-12 5 brachytherapy. These findings support the external validity of the trial and applicability of treatment findings to all patients who meet the criter ia used to judge eligibility for the trial.