Multiple primary cancer risk after therapy for Hodgkin's disease.

Forty-four antecedent, synchronous, and metachronous multiple primary cancers were identified among 41 patients who constituted 4.0% of 1028 patients initially treated for Hodgkin's disease during the years 1950-1954, 1960-1964, and 1968-1972. At 5 years post-therapy the cumulative probabilities of developing a multiple primary cancer for patients treated in 1950-1954, 1960-1964, and 1968-1972, were 1.14%, 1.48%, and 4.43%, respectively. At 10 years the cumulative probability of a multiple primary cancer was 2.54% for the 1950-1954 treatment group and 6.52% for the 1960-1964 treatment group. Among those patients 16-39 years of age, initially treated during the period 1960-1964, who had survived 6-10 years after receiving radiation plus single agent chemotherapy, we observed a significant 18-fold increase in the number of multiple primary cancers. A significant occurrence of two multiple primary cancers in a relatively small group of patients treated with chemotherapy only during the period 1968-1972 was also noted. Continued surveillance of patients extensively treated with combination chemotherapy and radiotherapy will enable assessment of the oncogenic potential of these modern therapeutic approaches to the management of Hodgkin's disease.