Purpose: Before recognizing mantle-cell lymphoma (MCL) as a distinct entity, these patients were grouped into low-grade (LG) or intermediate-/high-grade categories (IGHG) according to the Working Formulation and received various therapies. This was a unique opportunity to evaluate characteristics, behavior, response to treatment, and outcome of patients with MCL from two phase III trials conducted by the European Organization for the Research and Treatment of Cancer (EORTC): EORTC 20855 IGHG and EORTC 20856 LG.
Patients and methods: After histologic review, 64 diagnosed MCL patients (29 IGHG and 35 LG) were compared with other patients in their respective trials. In the IGHG group, patients received cyclophosphamide, doxorubicin, teniposide (VM26), prednisone, vincristine, and bleomycin (CHVmP-VB) or modified doxorubicin, cyclophosphamide, etoposide (VP 16), mechlorethamine, vincristine, procarbazine, and prednisone (ProMACE-MOPP). In the LG group, after receiving cyclophosphamide, vincristine, and prednisone (CVP) induction, patients were randomized between maintenance treatment with interferon alfa-2a (IFN) or no further treatment.
Results: MCL patients compared with IGHG subtypes showed a similar overall survival and response rate, but shorter duration of response and progression-free survival. Comparing with LG patients, their response rate, duration of response, and progression-free survival showed no difference, while their overall survival was nearly twice shorter. MCL patients treated with CHVmP-VB had the longest survival. No treatment showed any significant improvement in terms of progression-free survival.
Conclusion: These data confirm that MCL represents a clinicopathologic entity. In terms of survival, it behaves like IGHG subtypes, while in terms of progression-free survival, it behaves like LG lymphoma. It is still not clear which first-line treatment offers patients with MCL the best chance to obtain both a complete response (CR) and a long-term survival.