Aggressive management of second primary tumors in survivors of hereditary retinoblastoma.

Survivors of hereditary retinoblastoma are at increased risk for the development of second primary tumors, most commonly osteosarcoma. Recent molecular genetic data demonstrate that a pleiotrophic effect of the retinoblastoma gene may be responsible for the development of these sarcomas. This report describes the incidence of second nonocular malignancies among 53 infants seen at Stanford University Medical Center who have been followed a median of 11.7 years. Of these, 42 initially had bilateral disease and eleven had unilateral disease. Of 53 infants, 50 received irradiation either as part of the initial therapy or as treatment for recurrent disease. The actuarial survival for the entire group is 67% at 30 year follow-up with a median survival of 79% at 11.7 years. Eight patients developed eleven second primary tumors. All occurred in the group having hereditary retinoblastoma. Eight were within the previously irradiated field and three were at distant sites. The second tumors included seven osteosarcomas, one angiosarcoma, one rhabdomyosarcoma, one malignant fibrous histiocytoma, and one unclassifiable round blue cell tumor. The actuarial incidence of the development of a second primary malignancy was 6% at 10 years, 19% at 20 years, and 38% at 30 years. The latent period from treatment of retinoblastoma to the diagnosis of malignancy ranged from 5.2 years to 36.2 years (median 16 years). An aggressive approach with combined modality therapy including radical resection, re-irradiation and/or chemotherapy was used to treat these second primary tumors in five of eight patients. In four of the five, there was no evidence of disease at 22-72 months following treatment. In the three patients who did not receive aggressive combined treatment, there were no survivors. These data confirm the previously reported risk of developing a second primary tumor among survivors with hereditary retinoblastoma. Careful long-term follow-up for this genetically susceptible group is essential for early detection and implementation of curative therapy.