Chemorasistance as a function of the pretherapy tumor burden and the chemotherapy regimen administered: differences observed with 2 current chemotherapy regimens for advanced Hodgkin Lymphoma

BACKGROUND: The mature results from trials comparing ABVD (Adriamycin [doxorubicin], bleomycin, vinblastine, dacarbazine) and BEACOPP (bleomycin, etoposide, Adriamycin [doxorubicin], cyclophosphamide, Oncovin [vincristine], procarbazine, prednisone) chemotherapies in advanced Hodgkin lymphoma will be available in some years. An early comparison of their curative potential can however be obtained from an assessment of initial tumor burden and chemoresistance.PATIENTS AND METHODS: Less than a complete remission after treatment and relapse occurring within 12 months thereafter were assumed to be clinical expressions of chemoresistance. The tumor burden was calculated from the measurements of all the lesions documented by staging computed tomography (CT) and was normalized to body surface area to give the relative tumor burden (rTB). Using logistic regression analysis, the relationship between initial rTB, chemoresistance, and chemotherapy regimen administered was retrospectively studied in 222 patients selected from those enrolled in 2 similar randomized trials.RESULTS: The median rTB volumes were 157.9 cm(3)/m(2) in the 115 patients treated with ABVD vs. 154.6 cm(3)/m(2) in the 107 patients treated with BEACOPP, and the distribution of the volumes was identical in the 2 groups. The rTB was confirmed as the best predictor of early treatment failures (22 less than complete responses plus 21 early relapses). For the same rTB, the risk of chemoresistance to BEACOPP was about half that of the chemoresistance to ABVD or, for a given risk of chemoresistance, BEACOPP cured patients with an rTB 89.1 cm(3)/m(2) greater than that cured by ABVD (ie, more than 50% of the median tumor load of patients with advanced-stage disease).CONCLUSION: This account of rTB allows an early comparative evaluation of the curative ability of different chemotherapy regimens.