Multinational clinical and pathologic registry of retinoblastoma. Retinoblastoma International Collaborative Study report 2.
BACKGROUND: The Retinoblastoma International Collaborative Study is a multinational prospective clinical and pathologic registry designed to collect baseline clinical information, data on methods of treatment, and information on the subsequent clinical course of children with retinoblastoma. METHODS: 206 children with newly diagnosed retinoblastoma were evaluated in the participating clinical centers between 1 July 1987 and 31 December 1989. All of the children underwent comprehensive baseline assessment of multiple clinical variables prospectively according to a standard protocol. The recorded values were tabulated and analyzed. RESULTS: The 206 children with retinoblastoma included 99 boys (48.1%) and 107 girls (51.9%). The mean age at diagnosis was 21.2 mo in the total study group. One hundred twenty-seven of the 206 children (61.7%) had unilateral disease, while 79 (38.3%) had bilateral involvement. The mean age at diagnosis in the bilateral cases (14.6 mo) was substantially less than in the unilateral ones (23.5 mo). The great majority of patients (approximately 75%) had advanced disease (group V in both Reese-Ellsworth and Essen prognosis classifications) in the affected eye (unilateral cases) or the more severely affected eye (bilateral cases). CONCLUSIONS: This study shows that there is a dedicated group of international ophthalmologists and other physicians who are willing to participate in multicenter cooperative clinical studies of retinoblastoma and that a relatively large group of children with this ocular malignancy can be enrolled within this framework during a reasonably short time for the purposes of future studies.