Incidence of non-Hodgkin's lymphoma in patients treated for Hodgkin's disease.

The purpose of this study was to evaluate the incidence of non-Hodgkin's lymphoma (NHL) as a second tumor in patients treated for Hodgkin's disease (HD), as well as to establish the role of different variables in its appearance. Between January 1973 and June 1988, 101 patients with HD were treated according to the stage, with chemotherapy and/or radiotherapy. Complete remission was obtained in 87 patients. Five patients developed secondary NHL between the 77th and 124th month of complete remission. The median follow up was 73 months (range 3-227 months). The incidence of second NHL in our series was, 0%, 4.6% (CI 0-11%) and 17% (CI 4-32%) at 5, 10 and 15 years respectively. Cox's stepwise regression analysis performed with all initial and treatment covariates (sex, age, splenectomy, histology, stage and treatment modality) showed that the only statistically significant variable was the treatment received (p < 0.01). Cumulative incidence of NHL at 15 years, ranged from 0% for patients treated with radiotherapy or chemotherapy alone to 39.6% for those who received combined therapy (p = 0.002). We can conclude that the use of chemotherapy plus radiotherapy for treatment of HD increases the risk for the development of second NHL.