Hereditary retinoblastoma survivors had increased risk for subsequent cancers

An analysis of data from the Dutch retinoblastoma registry showed that patients who survived hereditary retinoblastoma had a substantially increased risk for subsequent malignancies.

The study included 668 survivors of retinoblastoma, diagnosed between 1945 and 2005; 298 patients had hereditary disease and 370 had nonhereditary retinoblastoma. Patients were followed for a median of 21.9 years.

Patients who survived hereditary retinoblastoma had a standardized incidence ratio (SIR) for subsequent cancers of 20.4 (95% CI, 15.6-26.1), which exceeded the risk for survivors of nonhereditary retinoblastoma (SIR=1.86; 95% CI, 0.96-3.24). The risk increase was largely among epithelial cancers including lung, bladder and breast.

Among those with hereditary disease, radiotherapy treatment was associated with a further increase in the risk for subsequent malignancies (HR=2.81; 95% CI, 1.28-6.19). After 40 years of follow-up for hereditary retinoblastoma survivors, the absolute excess risk for a second malignancy had increased to 26.1 excess cases per 1,000 person-years.

According to an accompanying editorial by Anna T. Meadows, MD, and Ann M. Leahey, MD, from the Children's Hospital of Philadelphia, the data from this study can aid in targeted surveillance efforts for this population. "Studies of children with retinoblastoma provide a window into the interaction in carcinogenesis of a mutated tumor suppressor gene and environmental mutagens," they wrote.

J Natl Cancer Inst. 2008;100:1771-1779.