Armando López Guillermo

There are no widely accepted prognostic indices for extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT). This study aimed to develop and validate a specific prognostic tool to personalize and optimize treatment of patients with MALT lymphoma. A prognostic index was built by Cox regression (stepwise selection) using data from 401 patients enrolled in the international randomized International Extranodal Lymphoma Study Group 19 (IELSG-19) trial (NCT 00210353). A validation set, including 633 patients, was obtained by merging 3 independent cohorts of MALT lymphoma patients. The 3 individual features maintaining the greatest prognostic significance for event-free survival (EFS, the main endpoint of the IELSG-19 trial) were age ≥70 years (hazard ratio [HR], 1.72; 95% confidence interval [CI], 1.26-2.33), Ann Arbor stage III or IV (HR, 1.79; 95% CI ,1.35-2.38), and an elevated lactate dehydrogenase level (HR, 1.87; 95% CI, 1.27-2.77). The prognostic index (MALT-IPI) constructed using these 3 parameters identified 3 groups: low, intermediate, and high risk (corresponding to the presence of 0, 1, or ≥2 of these factors, respectively). The 5-year EFS rates in the low-, intermediate-, and high-risk groups were 70%, 56%, and 29%, respectively. The MALT-lymphoma International Prognostic Index (MALT-IPI) also significantly discriminated between patients with different progression-free, overall, and cause-specific survival. The prognostic utility was retained in gastric and nongastric lymphomas, in each treatment arm (chlorambucil, rituximab, and rituximab plus chlorambucil), and was confirmed in the validation set. The new index, MALT-IPI, is a simple, accessible, and effective tool to identify MALT lymphoma patients at risk of poor outcomes. It may help define appropriate treatment approaches for individual patients.

Purpose There is no consensus on the optimal systemic treatment of patients with extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. The IELSG-19 phase III study, to our knowledge, was the first such study to address the question of first-line treatment in a randomized trial. Patients and Methods Eligible patients were initially randomly assigned (1:1 ratio) to receive either chlorambucil monotherapy (6 mg/m 2 /d orally on weeks 1 to 6, 9 to 10, 13 to 14, 17 to 18, and 21 to 22) or a combination of chlorambucil (same schedule as above) and rituximab (375 mg/m 2 intravenously on day 1 of weeks 1, 2, 3, 4, 9, 13, 17, and 21). After the planned enrollment of 252 patients, the protocol was amended to continue with a three-arm design (1:1:6 ratio), with a new arm that included rituximab alone (same schedule as the combination arm) and with a final sample size of 454 patients. The main end point was event-free survival (EFS). Analysis of chlorambucil versus the combination arm was performed and reported separately before any analysis of the third arm. Results At a median follow-up of 7.4 years, addition of rituximab to chlorambucil led to significantly better EFS (hazard ratio, 0.54; 95% CI, 0.38 to 0.77). EFS at 5 years was 51% (95% CI, 42 to 60) with chlorambucil alone, 50% (95% CI, 42 to 59) with rituximab alone, and 68% (95% CI, 60 to 76) with the combination ( P = .0009). Progression-free survival was also significantly better with the combination ( P = .0119). Five-year overall survival was approximately 90% in each arm. All treatments were well tolerated. No unexpected toxicities were recorded. Conclusion Rituximab in combination with chlorambucil demonstrated superior efficacy in mucosa-associated lymphoid tissue lymphoma; however, improvements in EFS and progression-free survival did not translate into longer overall survival.

Abstract Background. The salivary gland is one of the most common sites involved by nongastric, extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT). A large series of patients with long-term follow-up has not been documented. This multicenter, international study sought to characterize the clinical characteristics, treatment, and natural history of salivary gland MALT lymphoma. Methods. Patients with biopsy-confirmed salivary gland MALT lymphoma were identified from multiple international sites. Risk factors, treatment, and long-term outcomes were evaluated. Results. A total of 247 patients were evaluated; 76% presented with limited-stage disease. There was a history of autoimmune disorder in 41%, with Sjögren disease being the most common (83%). Fifty-seven percent of patients were initially treated with local therapy with surgery, radiation, or both; 37 of patients were treated with systemic therapy initially, with 47% of those receiving rituximab; and 6% of patients were observed. The median overall survival (OS) was 18.3 years. The median progression-free survival (PFS) following primary therapy was 9.3 years. There was no difference in the outcomes between patients receiving local or systemic therapy in first-line management. On multivariate analysis, age <60 years and low to intermediate international prognostic index were associated with improved OS and PFS; Sjögren disease was associated with improved OS. Conclusion. Salivary gland MALT lymphoma has an excellent prognosis regardless of initial treatment, and patients with Sjögren disease have improved survival. Risks for long-term complications must be weighed when determining initial therapy. Implications for Practice: Patients with salivary gland extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) have an excellent prognosis, particularly those with associated Sjögren's disease. A wide range of available therapies may provide similar durable rates of disease control and survival. Therefore, an important goal in selection of therapy should be to minimize morbidity from treatment. When determining initial therapy for these patients, practitioners should consider the potential side effects and long-term toxicities of treatment.

Early progression of disease (POD) within two years from diagnosis is linked with poor overall survival (OS) in follicular lymphoma but its prognostic role is less clear in extranodal marginal zone B-cell lymphoma (EMZL). We sought to identify prognostic factors associated with early POD and to determine whether is associated with inferior OS. We analyzed the impact of early POD in the IELSG19 clinical trial dataset (training set of 401 patients randomly assigned to chlorambucil or rituximab or chlorambucil plus rituximab). Reproducibility was examined in a validation set of 287 patients who received systemic treatment. In both sets, we excluded from the analysis the patients who, within 24 months from treatment start, died without progression or were lost to follow-up without prior progression. OS was calculated from progression in patients with early POD and from 24 months after start of treatment in those without (reference group). Early POD was observed in 69 of the 384 (18%) evaluable patients of the IELSG19 study. Patients with high-risk MALT-IPI were more likely to have early POD (p=0.006). The 10-year OS rate was 64% in the early POD group and 85% in the reference group (HR= 2.42, 95%CI, 1.35-4.34; log-rank P=0.002). This prognostic impact was confirmed in the validation set, in which early POD was observed in 64 out of 224 (29%) evaluable patients with 10-year OS rate of 48% in the early POD group and 71% in the reference group (HR= 2.15, 95%CI, 1.19-3.90; log-rank P=0.009). In patients with EMZL who received front-line systemic treatment, early POD is associated with poorer survival and may represent a useful endpoint in future prospective clinical trials.