Fifteen year experience in Hodgkins' Disease: Role of combined modality treatment and splenectomy in the incidence of secondary acute leukemia

BACKGROUND: Following irradiation alone, secondary acute leukemia is extremely uncommon; following chemotherapy alone, the risk is increased, but not as much as when continued maintenance chemotherapy or combined modality treatments are used. PATIENTS: The risk of secondary acute nonlymphocytic leukemia (ANLL) was assessed in 552 patients with Hodgkin's disease (HD), who were diagnosed at the Hematology Institute of Bologna from 1970 through 1984 and followed-up through July, 1990. Median follow-up time was 12 years. RESULTS: ANLL developed in 14 of 328 patients treated with the combined modality of extended-field radiotherapy (RT) plus chemotherapy (CT). All ANLL was observed in patients who had received the mechlorethamine-vincristine-procarbazione-prednisone (MOPP) regimen. No ANLL was documented among 115 patients treated with RT alone, nor among the 109 given CT alone. Leukemia, which developed 34-184 months after diagnosis of HD, was always preceded by a preleukemic phase and was fatal (after 1-12 months) to 13 patients. The karyotype of the leukemia cells was studied in 11 of the 14 patients and was always abnormal. CONCLUSIONS: A Cox's Linear Logistic Model that was performed did not demonstrate that the treatment categories, age, sex, and splenectomy were prognostic factors. Because all ANLL was observed in patients who were treated with extended-field RT plus MOPP and who had undergone splenectomies at diagnosis of HD, further research with larger numbers of patients and longer follow-up should be pursued. Thus with such additional data, clinicians could come to appreciate fully the statistical significance of our interesting observations.