Tumour burden at diagnosis as the main clinical predictor of cell resistance in patients with early stage, favourable Hodgkin lymphoma treated with VBM chemotherapy plus radiotherapy

Abstract

We verified whether early resistance to treatment can be predicted in a subset of patients with very favourable, early stage Hodgkin lymphoma, treated with VBM (vinblastine, bleomycin and methotrexate) chemotherapy and involved-field radiotherapy, an effective combination with very low early and late toxicity. The relative tumour burden (rTB) was volumetrically measured from the staging computed tomography and analysed together with the parameters of pre-therapy evaluation in 61 patients enrolled into the protocol MH-1b of the Gruppo Italiano Studio Linfomi between 1996 and 2003. Early failure, codified by either less than complete remission (i.e. partial/null response or progression) or early relapse (within 12 months from the end of therapy), was considered as clinical expression of resistance to treatment. Logistic regression and failure-free survival were the statistical tools for the analysis. The rTB demonstrated to be the best predictor of early failure, outperforming every other pre-treatment parameter, International Prognostic Score included. With a mean rTB value of 44.964 ± 34.788 cm(3)/m(2) in the 53 patients successfully treated and of 130.185 ± 63.993 cm(3)/m(2) in the eight with early treatment failure, the risk of resistance showed fivefold and 10-fold increases at rTB of 52.002 and 74.497 cm(3)/m(2), respectively. Only two patients relapsed more than 12 months after the end of therapy; both had a high initial rTB. The rTB is the best predictor of resistance also in the subset of patients with very favourable, early stage disease. Safe rTB limits are proposed for successful administration of VBM chemotherapy plus involved-field radiotherapy.

Keywords: Hodgkin lymphoma; cell resistance; chemotherapy; radiotherapy; tumour burden.