Therapy of IIIA Hodgkin's disease

Abstract

The treatment of Hodgkin’s disease is a complicated affair with many guidelines for management of a variety of clinical presentations but also considerable controversy regarding the treatment of different subsets. Perhaps the most controversy surrounds the management of “intermediate” stages of Hodgkin’s disease, IIIA and IIB. The former is a subject of a report by Dr. Powlis and his colleagues in this issue of the Int. J. Radiat. Oncol. Biol. Phys. Before addressing some of the issues raised by that report, it is well to remember that Hodgkin’s disease is an uncommon disorder with an estimated 7,300 new cases for the United States in 1 98718 (compared with 130,900 for breast carcinoma, for example) and that Stage IIIA is an uncommon subset, comprising about 15% of all Hodgkin’s disease.’ When one starts to ask questions about the management of subsets of IIIA disease, it is evident that the answers will not be forthcoming from prospective randomized trials and that any answer from retrospective data analysis is likely to be incomplete. With that introduction, let’s examine the Powlis report from the Joint Center for Radiation Therapy at Harvard and the University of Pennsylvania with respect to how it agrees with prior studies, how it differs, and what the reasons for the differences might be. We will also try to establish some unifying principles from the data to guide the clinician who, in the last analysis, has to make some hard decisions and may have difficulty putting the patient in precisely the right pigeonhole. Powlis et al. have looked specifically at the subset of III, Hodgkin’s disease patients which they have labelled “minimal” IIIA disease and examined the impact of three different kinds of treatment, combined modality therapy (CMT), total nodal irradiation (TNI), and mantle and para-aortic irradiation (MPA). It is evident from the paper that the three groups are not entirely comparable with respect to the patients receiving these treatments and that the MPG group is a more favorable one in several respects, and additionally has been followed for considerably less time than the other two groups. Nevertheless, the CMT group has the best results with all 22 patients alive and only 1 relapse. Result with TN1 or MPA are very similar to one another with about half of the patients relapsing in each group and about 80% of patients alive in each group. About 90% of the III1 patients had splenic involvement and the authors examined the influence of the number of splenic nodules on outcome, as suggested by Hoppe et d7 Patients getting CMT all did very well no matter what the number of splenic nodules. With TN1 patients with greater than 5 splenic nodules relapsed considerably more often than those with less than 5; furthermore, patients with nodular sclerosis/lymphocyte predominant histologies seemed to do better than those with mixed cellularity or lymphocyte depletion disease. For patients treated with MPA irradiation, the number of splenic nodules did not appear to matter, but the histology of the disease did. The authors concluded that: 1. Within the group of III1 patients, only the subset of patients with less than 5 splenic nodules and with nodular sclerosing/lymphocyte predominant histology were suitable for radiation therapy alone. 2. That MPA irradiation was as good as TNI. 3. All other IIIA patients should be treated with combined modality therapy.