SIGNIFICANT SURVIVAL IMPROVEMENT OF THE ELDERLY PATIENTS AND WOMEN WITH LOW/INTERMEDIATE RISK MIPI MANTLE CELL LYMPHOMA OVER THE PERIOD OF 14 YEARS

ABSSUB-5588

Background: Mantle cell lymphoma (MCL) is an aggressive type of B-cell non-Hodgkin lymphoma (NHL) with poor prognosis. In recent years the outcome of patients with MCL has been improved mainly by implementation of rituximab (R), high-dose araC (HDAC) into induction regimen, consolidation with autologous stem cell transplant (ASCT) and R maintenance.

Aims: A single center retrospective analysis of MCL patients treated since 1999 to 2012.

Methods: We retrospectively analyzed 185 consecutive patients with confirmed diagnosis of MCL treated at the Charles University General Hospital since 1999 to 2012. The whole cohort comprised 71% men and 29% women with median age of 66 years (both men and women). Most patients had advanced-stage disease (stage IV= 80% patients) and adverse prognosis according to the mantle-cell lymphoma prognostic index (MIPI): MIPI high (MIPI-H)= 48.1%, MIPI intermediate (MIPI-I)= 23.8% and MIPI low (MIPI-L)= 24.9%. Out of all 185 patients, 2 were not treated. Three most common types of induction therapy included R-CHOP (n=52), Nordic protocol (alternating 3 cycles of R-Maxi-CHOP and 3 cycles of R-HDAC, n=45) and R-COP (n=26). 45 patients received ASCT. Most patients (86.9%) had rituximab as part of induction.

Results: Overall response rate for all patients was 81.9% (CR/uCR= 57.9%, PR= 24%). Median progression-free survival (PFS) and overall survival (OS) was 2.84 years, and 6.27 years, respectively. The median follow-up was 4.4 years. The analysis revealed several interesting findings. First, patients (pts) diagnosed in 2006-2012 (2006+) vs 1999-2005 (1999+) had significantly better PFS (median 2.04 vs 3.38 years, p= 0.0222) and trend toward better OS (median 7.2 vs. 4.3 years, p= 0.11). Curiously, the age-stratified analysis revealed that only elderly patients (≥ 60 years) in 2006+ group had significantly improved PFS (median 2.74 vs. 1.63 years, p= 0.0086) and trend toward improved OS (median 4.2 vs 2.3 years, p=0.0625) compared to those in 1999+ group. The younger patients in 2006+ compared to 1999+ group had similar PFS (median 5.52 vs. 5.51 years, p= 0.884) and OS (median undefined in both subgroups, p= 0.784). The reason for the improved outcome of the elderly patients in recent years is probably a consequence of introduction of rituximab maintenance. In the elderly groups 1999+ and 2006+ two of 44 and 32 of 66 pts received rituximab maintenance, respectively. The elderly pts 2006+, who received rituximab maintenance (compared to those, who did not) had higher PFS (median 4.5 vs 2.23 years, p= 0.0055) and OS (median undefined vs 3.41 years, p= 0.0018). Second, MIPI discriminated well into 3 subgroups of patients only in the whole cohort. However, in the age-stratified analysis there remained only two relevant MIPI subgroups: MIPI-I merged with MIPI-H (in younger pts) or with MIPI-L (in elderly pts). Finally we observed trend toward better OS in the subcohorts of women with MIPI-L and MIPI-I compared to men (MIPI-L median undefined vs 8.48 years, p= 0.0692; MIPI-I median 10.51 vs 4.56 years, p= 0.0657). PFS was significantly prolonged in women with MIPI-I compared to men (median 8.31 vs 5.59 years, p= 0.539), but did not differ in women with MIPI-L (median 8.04 vs. 2.44 years, p= 0.0237).

Summary/Conclusion: On the large single center cohort of unselected MCL patients we demonstrated significant outcome improvement of elderly patients but not younger patients during the last 7 years. We found that MIPI discriminated only two prognostic subgroups when used in age-defined cohorts of patients. Finally, women with low and intermediate risk MIPI appeared to have better outcome compared to man.

Financial support: PRVOUK-27/LF1/1, IGA-MZ NT/13072-4.

Keywords: Elderly, Mantle cell lymphoma, Rituximab

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