LY-08. First-line therapeutic strategy and clinical prognosis in the patients with marginal zone lymphoma: Pavlov University experience

Summary

Marginal zone lymphoma (MZL) is the second most common subtype of indolent B-cell non-Hodgkin’s lymphoma. MZL comprises approximately 6% of all lymphoid malignancies. Based on the World Health Organization data MZL is subdivided into 3 major categories: extranodal MZL (EMZL), MALT, nodal MZL (NMZL), and splenic MZL (SMZL). Due to the lack of established standards of therapy and the limited amount of data on the results of treatment in the Russian Federation, the analysis of the histological, clinical and epidemiological characteristics of MZL is an urgent topic for study. The aim of this work is to analyze the strategy of first-line therapy for patients with MZL in real clinical practice at the Raisa Gorbacheva Memorial Research Institute, Pavlov University.

Patients and methods

A retrospective single center study included 77 patients (25m/52f) with a histologically confirmed diagnosis of MZL. The primary endpoint was overall survival (OS) of patients with MZL, defined as the time from the start of first-line therapy to death from any cause. The secondary endpoint was progression-free survival (PFS), the time from the start of first-line therapy to disease progression, relapse, or death from any cause, PFS was censored at the time of initiation of second-line therapy. In assessing survival, data were censored according to the date of last contact if there was no event at the time of follow-up. Survival were estimated using the Kaplan-Meier method.

Results

The median age of patients was 70 (28-97). Among the morphological subtypes, SMZL occurred in 42% (n=33), MALT in 29% (n=22), NMZL in 29% (n=22). At the time of diagnosis, stage I was observed in 13% (n=10), II – in 5% (n=4), III – in 1% (n=1), IV – in 77% (n=59), in 4% (n=3) no information available. At the time of diagnosis, ECOG0-1 in 87% (n=67), ECOG2-3 in 13% (n=10). B-symptoms were detected in 40% (n=31). FISH was performed in 29% (n=22), chromosomal rearrangements involving the p53 was detected in 23% (n=5). The 1^st line therapy included: R-mono for 64%(n=49), R-CHOP for 12%(n=9), RB for 9% (n=7), surgical treatment for 5% (n=4), CHOP-like regimens for 4%(n=3), other options of the therapy 4% (n=3), observation for 3% (n=2). Maintenance therapy with rituximab was performed in 40% (n=31). Among patients who received conservative treatment, complete response after the first line of therapy was observed in 21% (n=16), partial response in 39% (n=30), disease stabilization in 13% (n=10), progression in 21% (n=16), no data in 6% (n=5). The median follow-up from the start of first-line therapy was 29 months (2-101). Median OS not reached. Three-year PFS for the entire study group – 62.2%. The median progression-free survival was 45 months.

Conclusions

Analysis of clinical characteristics and first-line treatment strategy in patients with MZL in real clinical practice was performed. The basis of MZL therapy is rituximab therapy in combination with various regimens of mono- and polychemotherapy. Patients in the study population had a favorable clinical prognosis. For reliable identification of the dependence of outcomes and the chosen treatment regimen, it is necessary to increase the number of patients and the duration of observation.

Keywords

Marginal zone lymphoma, first-line therapy.