Quantitative risk of second cancer in patients in first complete remission from early stages of Hodgkin's disease.

Thirty-three second cancers, excluding basal cell carcinomas of skin and in situ carcinomas of the cervix uteri, were observed among 1,084 patients in first complete remission from Hodgkin's disease treated from 1964 to 1981 by the Lymphoma Group of the European Organization for Research and Treatment of Cancer and the Groupe Pierre et Marie Curie. Five of these second cancers were acute nonlymphocytic leukemias (ANLL), and five were non-Hodgkin's lymphomas (NHL). The 15-year cumulative proportion was 7.6% for second cancers; 0.7% for ANLL; and 1.2% for NHL. For solid tumors (ST) occurring in a previously irradiated area, it was 1.0% after regional radiotherapy (RT); after extended-field RT, it was 8.2% (P = .009). The relative risk (RR) of ANLL after combined chemotherapy with mechlorethamine, vincristine, procarbazine, and prednisone plus RT (relative to the general population incidence rates) was 39 (P less than .001) during the first 4-year period; it was not significantly increased in patients treated by RT without combined chemotherapy. Similar RR was observed for NHL (RR = 31; P less than .001). Moreover, an increased RR of NHL (RR = 53; P less than .001) was observed in patients treated by RT without combined chemotherapy after 10 years. For ST, no significant increased risk was observed regardless of the treatment. There is, however, a slight tendency for the risk of ST related to extended-field RT to increase after 10 years.