Second malignancies complicating Hodgkin's disease in remission.

The incidence of second tumours occurring in the course of Hodgkin's disease has been investigated in a series of 452 patients treated with standard chemotherapy or radiotherapy, combination chemotherapy alone, intensive radiotherapy alone, or both intensive radiotherapy and combination chemotherapy administered in sequence. 16 tumours were noted. When analysed according to mode of treatment, 6 cases occurred in a group of 62 patients who received both modalities. When analysed for age, sex, and man-years of follow-up, this group appears to have 14-5 times the risk of developing a second tumour. However, that subgroup which had a complete remission after intensive radiotherapy followed by a relapse of disease, prior to receiving combination chemotherapy, had the highest risk with 18-5 times greater incidence of second tumour than expected. It is noteworthy that, of the 16 second tumours, 2 were acute myeloid leukaemia; in both cases a similar chromosomal abnormality (45 chromosomes, C-group deletion) was noted. The mechanism of oncogenesis may represent a combination of the immunosuppressive effects and cellular effects of those forms of treatment.