Refractoriness to rituximab-based therapy and elevated serum B2-microglobulin predict for inferior survival in marginal zone lymphoma.

Short responses to immunochemotherapy predict for an inferior OS in follicular lymphoma. We set out to determine whether this is also the case in marginal zone lymphoma. A group of 139 marginal zone lymphoma (MZL) patients treated with front-line immuno- or immunochemotherapy (I/ICT) were categorized into I/ICT-refractory (non-response or relapse/progression within six months of treatment response assessment) or I/ICT-sensitive. Twenty-three patients (17%) were refractory. Refractory patients had inferior OS (4-yr probabilities of 57% vs. 83%, p = .0003) as did those with beta2-microglobulin (B2M)>3 mg/L (4-yr probabilities of 80% vs. 100%, p = .0029). On multivariable analysis they both showed a borderline significant correlation with OS (p = .06 and .07, respectively). B2M > 3 mg/L was also an adverse prognostic factor for progression-free survival in both univariable (4-yr probability of 61% vs. 83%, p = .02) and multivariable analysis (HR 2.9, p = .02). In conclusion, B2M and refractoriness to I/ICT may identify patients with MZL at higher risk of inferior survival.