Second malignant neoplasms in patients treated for Hodgkin's disease with radiotherapy or radiotherapy and chemotherapy.

The incidence of second malignant neoplasms (SMN) was assessed in 248 patient with Hodgkin's disease (HD) treated by radiotherapy alone (XRT) or in combination with chemotherapy (XRT + C) between January/1960 and June/1977. Radiation therapy was categorized as less than extended field (less than EF), extended field (EF) or total nodal irradiation (TNI). Chemotherapy was scored as single agent (SAC) or multiagent (MAC). MAC consisted primarily of either nitrogen mustard, vincristine, prednisone and procarbazine (MOPP) or cyclophosphamide, vinblastine, procarbazine and prednisone (CVPP). Ten metachronous malignancies occurred 1-21 years (median 10 years) after the diagnosis of HD. With a median follow-up of 6 years the observed-to-expected ratio (O/E) was 4.2 for XRT alone and 7.6 for XRT + MAC. For 46 patients with greater than or equal to 10 years follow-up (median 13 years) the O/E ratio was 16.1 for XRT and 26.5 for XRT + MAC. All SMN occurred in patients who had not had a splenectomy at or prior to the time of HD diagnosis. Only four of nine solid SMN were within treatment portals or near portal margins. The diagnosis of another malignant neoplasm was made prior to or simultaneous with the diagnosis of HD in four additional patients. This observation, and the occurrence of five of six SMN outside of the treatment field in the XRT alone group, suggest that there may be factor(s) associated with the incidence of SMN in HD in addition to treatment itself.