Long-term follow-up of survival in Hodgkin's lymphoma.

To the Editor: In 1992, the Cancer and Leukemia Group B (CALGB) reported the results of a prospective three-group randomized trial involving 359 patients with Hodgkin’s lymphoma. This trial compared the following regimens: doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) for 6 to 8 months, mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) for 6 to 8 months, and MOPP alternating with ABVD for 12 months.1 The trial was limited to patients with advanced disease (clinical stages III and IV). No radiotherapy was administered. The results, published in the Journal in 1992, indicated an eventfree survival advantage of ABVD over MOPP but no differences in overall survival between the ABVD and MOPP groups. These findings were reemphasized in a follow-up study of the data published in 2002.2 We report further follow-up data from a median follow-up period of 18.1 years (Fig. 1). We analyzed the results from a follow-up period of at least 20 years. The fact that overall survival was still equivalent among the three groups despite a higher failure rate associated with MOPP is a testimony to the effective salvage treatments for Hodgkin’s lymphoma. A review of the 12 consecutive series of prospective, randomized therapeutic trials involving a total of 6200 patients with advanced Hodgkin’s lymphoma that have been published since 2003 revealed only one trial in which a small statistically significant difference in overall survival was noted.3 Relatively small but statistically significant differences in event-free survival, if seen, were corrected in terms of overall survival by effective salvage therapy. Long-term results with the use of ABVD alone in the above-mentioned CALGB trial are often used to compare newer regimens. This comparison is not valid, since the trial began in 1982. The 5and 10-year rates of both event-free and overall survival have increased from 73.5% and 62.0%, respectively, between 1980 and 1984 and, more recently, from 85.0% and 80.0%, respectively, in the 2000–2004 interval as shown in the Surveillance, Epidemiology, and End Results program.4 More intensive and toxic chemotherapy may confer a statistical event-free survival advantage but, unless overall survival is improved, the greater toxicity could compromise quality of life without a survival benefit. However, the identification of high-risk patients on the basis of persistently positive findings on positron-emission tomography 4 col 22p3 Ev en tfr ee S ur vi va l ( % ) 100