Retinoblastoma Biomarker Study

Retinoblastoma is a rare pediatric ocular tumor caused by germline and/or somatic mutations in the tumor suppressor gene RB1. Survivors of retinoblastoma, particularly those with the hereditary form of the disease (germline RB1 mutations) are highly susceptible to developing additional malignancies, which are a major cause of morbidity and mortality. Since 1984, REB has followed a cohort of 2136 (including 1,995 one-year) retinoblastoma survivors to investigate the contributions of treatment and genetic risk factors to second cancer etiology. The last systematic follow-up for second cancer incidence and cause-specific mortality was completed in 2009. As the cohort ages, we now propose to conduct another interview survey to collect information on newly diagnosed second cancers. Additionally, we propose to expand collection of germline DNA for additional molecular studies in survivors. Retinoblastoma survivors have now entered adult ages when epithelial tumors would be expected to occur with greater frequency. Given that the somatic mutations in the RB1 pathway have been identified in several epithelial tumors (bladder, brain, breast, esophagus, liver, lung, prostate) in addition to sarcomas, it is important to collect new information on these epithelial tumors, and to investigate whether the previously identified high risks of sarcomas and melanoma will persist as the cohort ages. Additionally, our understanding of genetic susceptibility to second cancers is limited. Given that this is the only cohort of long-term survivors of retinoblastoma being followed in the U.S., combined with the leadership role of REB in the study of second cancers, continued follow-up of this cohort will provide unique clinical and epidemiologic data on the long-term cumulative risk of second cancers in this distinctive cohort of childhood cancer survivors.