Watch-and-wait or immediate immunotherapy/immunochemotherapy in patients with phase IE primary pulmonary MALT lymphoma? A multicenter retrospective study.

Primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is rare, and the optimal frontline treatment has not taken shape so far. It is still debatable whether the watch-and-wait (W&W) policy is beneficial to patients, especially in the early stage. This study was to compare the efficacy of W&W with rituximab single agent or combined chemotherapy (R/R-Chemo) on primary pulmonary MALT patients with localized disease. Clinical characters and effect on 28 patients with primary pulmonary MALT (IE phase) were analyzed. Among the 28 patients, 14 were grouped into W&W cohort, and 14 were immediately treated with R/R-Chemo. The median follow-up duration was 62 months. The estimated median time to treatment failure (TTF) in the W&W cohort and immediate R/R-Chemo cohort was 29 months and 59 months, which were not significantly different (P = 0.667). The estimated median time of overall survival (OS) in the W&W cohort and immediate R/R-Chemo cohort was 78 months and 76 months, which were also not statistically significant (P = 0.696). Concerning prognosis, there is no difference between patients with primary pulmonary MALT (IE phase) treated with W&W and with timely R/R-Chemo.