Second cancer following cutaneous melanoma and cancers of the brain, thyroid, connective tissue, bone, and eye in Connecticut, 1935-82

Abstract

The risk of second primary cancers developing was evaluated in individuals with 6 rare tumors in Connecticut between 1935 and 1982. Small but significant excesses of all second cancers occurred in patients with cutaneous melanoma (42%), and cancers of the brain (59%), thyroid (49%), connective tissue (23%), bone (66%), and eye (40%). In individuals with cutaneous melanoma, the highest risks were for subsequent cutaneous melanomas [relative risk (RR) = 8.5] that persisted throughout all intervals of observation. The risk for second melanomas was higher in persons under age 40, consistent with a heritable component. Connective tissue tumors and breast cancers also occurred in excess. Among patients with brain cancer, an increase of melanoma was observed that may represent an underlying neural crest abnormality, although no excess of brain cancer was seen after melanoma. Reciprocal increases of bone cancer after connective tissue cancer and connective tissue cancer after bone cancer point to shared risk factors, such as high dose radiotherapy or genetic susceptibility states. An anticipated high risk of osteogenic sarcoma following Ewing's sarcoma was not seen. An excess of breast cancer (RR = 1.9) after thyroid cancer indicates common etiologic factors. Expected excesses of bilateral retinoblastoma and bone cancer after retinoblastoma were seen. Tumors commonly treated with alkylating agents or nitrosoureas (melanoma, brain, connective tissue) showed slightly elevated risks of acute nonlymphocytic leukemia. Prostate cancer was frequently found to be in excess, but this is likely an artifact due to ascertainment bias.