Medical radiation exposure and risk of sporadic retinoblastoma.

Abstract

While there is evidence that parental exposure to medical radiation is associated with increased risk of sporadic bilateral retinoblastoma in offspring, this association has not been confirmed. Additionally, the relationship between paternal and maternal exposures and sporadic unilateral retinoblastoma has not been fully investigated. Data were obtained from two large multicenter case-control studies of retinoblastoma. For the paternal analyses, 268 bilateral cases, 155 unilateral cases, and 358 controls were included. For the maternal analyses, 298 bilateral cases, 184 unilateral cases, and 404 controls were included. Logistical regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) to evaluate the associations between parental exposures to medical radiation and sporadic retinoblastoma, while adjusting for potential confounders. Paternal exposure to medical radiation was not significantly associated with sporadic bilateral retinoblastoma in offspring. However, increasing paternal exposure to gonadal radiation was associated with increased risk of unilateral retinoblastoma (P-trend=.03). Maternal history of upper and lower gastrointestinal (GI) series was associated with bilateral retinoblastoma (OR=1.9, 95% CI: 1.1-3.2 and OR=6.9, 95% CI: 2.9-16.4, respectively). However, there was no association between maternal exposure to medical radiation and unilateral retinoblastoma in offspring. Our investigation adds to the evidence that medical radiation exposure in fathers as well as mothers prior to pregnancy may increase the risk of germline alterations leading to the development of retinoblastoma in their offspring. However, our findings could point to a more complex etiological framework for this important pediatric malignancy.