Primary treatment with autologous stem cell transplantation in mantle cell lymphoma: outcome related to remission pretransplant

Objective: The aim of the first Nordic mantle cell lymphoma (MCL) protocol was to study the clinical significance of an augmented CHOP induction chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) and to examine the prognostic significance of stem cell contamination rates in newly diagnosed patients with MCL. Patients and methods: Forty-one newly diagnosed patients below 66 yr were enrolled and given three series of an augmented CHOP regimen. Responders underwent stem cell mobilization with a fourth course of CHOP, stem cell harvest and ASCT. Stem cell purging was optional in the protocol and followed the routine of each participating centre. The number of tumour cells in the reinfused autografts was estimated by flow cytometry or quantitative PCR. Results: Induction therapy led to complete remission (CR) in 11 of 41 patients (27%), partial remission (PR) in 20 of 41 patients (49%) and no response in nine patients (22%), whereas one patient was not evaluable. Twenty-seven of the 31 responders underwent ASCT and 24 achieved or maintained a CR. The overall and failure-free 4-yr survival on intention-to-treat basis were 51% and 15%, respectively. Among the transplanted patients, a significantly increased failure-free (P < 0.03) and overall survival (P = 0.03) was noted among patients transplanted in CR compared with PR, respectively. By contrast, reinfusion of highly variable numbers of tumour cells with the autografts (range 0.71-80 x 10(6) tumour cells), did not affect outcome. Conclusion: In MCL, an important strategy to improve the outcome will be to intensify the induction chemotherapy