DCEG researchers are studying retinoblastoma (Rb), a cancer that forms in the tissues of the retina (the light-sensitive layers of nerve tissue at the back of the eye). Retinoblastoma usually occurs in children younger than five years, and may be hereditary or nonhereditary (sporadic).
Despite excellent survival rates among children treated for Rb, survivors with a germline mutation in their Rb1 gene (hereditary Rb) are prone to subsequent cancers including sarcomas, melanoma, and cancers of the brain and nasal cavity. Radiotherapy appears to increase the risk, suggesting a gene-environment interaction.
DCEG researchers continue to monitor cancer incidence and mortality in the largest cohort of Rb survivors diagnosed from 1914 through 2007 in the United States. Analysis of mutations in the Rb1 gene is in progress to identify specific mutations that may be related to the risk of a second cancer. Rb patients who have developed a melanoma, and their first degree relatives, have been examined clinically for dysplastic nevi. Dysplastic nevi are moles that look different from common moles in color, shape, size, and surface texture, and have the potential to develop into malignant melanoma.
Rb survivors are interviewed periodically to obtain cancer risk factor and current health data. Newsletters and a website inform the cohort about progress of the follow-up study and their second cancer risk, and provide cancer screening recommendations.