The Outcome of Mantle Cell Lymphoma patients after Treatment Failure and Prognostic value of Secondary Mantle Cell International Prognostic Index (sec MIPI)

Background: MCL is a distinct lymphoma entity with improved outcome achieved by the introduction of rituximab, high dose Ara-C and autologous stem cell transplantation (ASCT) into the first line therapy. The outcome of the relapsed patients (pts) remain however poor and there is little data on the outcome after subsequent relapses and there is no information on secondary MIPI prognostic value.

Aim: To analyze the outcome of the MCL patients after first line treatment failure and to evaluate the prognostic role of the sec MIPI which is MIPI calculated at the time of relapse/progression.

Methods: This analysis is a part of the Lymphoma project in which consecutive lymphoma patients are registered since the year 1999. Altogether 519 newly diagnosed MCL patients were registered in 5 university centers and 9 regional departments between 1999 and 2011. Patients who were treated with rituximab as part of the first line treatment (n=388) were included into the analysis. The diagnoses were confirmed according to WHO classification in the reference pathology centers. The median follow up is 4.5 years.

Results: The whole cohort consists of 261 males and 127 females (2.1:1) with median age 65 y (28-87), the majority of pts had advanced disease (CS IV in 81.6% pts), PS ECOG ≥ 2 in 23.6% pts, elevated LDH in 52.5% of pts. The MIPI risk profile was as follows: low risk 21.7%, intermediate risk 27.2% and high risk in 51.1%. All pts received rituximab as part of the induction, 48.7% pts received CHOP, 5.7% alternation of CHOP and HD Ara-C, 26.2% intensive induction with HD Ara-C, 10.3% CVP, 6.4% FC. High dose therapy with ASCT was performed in 23.9% of pts. The ORR was 89.0% with 63.8 CR/CRu, 6.3% had stable disease and 4.9% were primary progressive. The PFS and OS were 2.9 y and 5.5 y with significant impact of MIPI risk (p<0.0001) for both PFS and OS. There were observed 179 relapses/progressions (R/P) and 70 deaths not related to subsequent progression. The cohort of patients with 1^st R/P consisted out of 125 males and 54 females (2.3:1) with median age 68 years (38-89). The sed MIPI at the time of 1^st R/P was low in 12.7% pts, intermediate in 32.1% and high 59.8% pts. Rituximab was used in 69.5% of patients, DHAP or ESHAP was used in 25.1% cases, FC in 22.8% of cases, CHOP like regimen in 9.4%, HD Ara-C in 11.8%, only 4.7% were treated with targeted therapy temsirolimus or lenalidomide. Altogether 77.2% pts were treated with the polychemotherapy and 22.8 with monotherapy. ASCT and AlloSCT were performed in 5.5% and 8.7% pts resp. During follow up there were observed 74 deaths not related to subsequent progression and 53 2^nd R/Ps. The median of 2^nd PFS and 2^nd OS from the date of 1^st R/P was 1.0 and 1.3 years resp. The sec MIPI low vs. intermediate vs. high risk had significant prognostic impact on 2^nd PFS: 5.8 vs 1.7 vs 0.9 years (p<0.0001) (fig 1) as well as on OS : 5.8 vs 3.4 vs 1.1 years (p<0.0001) (fig 2). The cohort of 53 pts with 2^nd R/P had median age 68 (38-85) yers, male/female ratio was 1.4. Rituximab was used in 45.9% of treated patients and 48.3% of pts were treated with single drug. During follow up 11 pts developed 3^rd R/P and other 30 pts died due to current progression, toxicity or in remission. The median of 3^rd PFS from the time of 2^nd R/P was 6.8 m and OS 7.4 months. Pts who were treated for 3^rd R/P recieved rituximab in 50% of cases and the majority (81.2%) were treated with other single drug. The median of 4^th PFS from 3^rdR/P was 4.9 m and OS 5.5 months .

Conclusions: Our analysis of relapsed MCL patients shows that 1: Median PFS from the Dg was 2.9 y but each subsequent relapse resulted in significantly shorter PFS median 12.1, 6.8 and 4.9 months resp. 2: The median OS from Dg was 5.5y but after each relapse it became shorter - 15.7 m, 7.4 m and 5.5 months resp. 3: The sec MIPI at the time of relapse discriminates the groups with significantly different prognosis.