Long-term Outcomes and Cardiac Mortality after Radiotherapy for Primary Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma.

PURPOSE:Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is a rare but indolent B-cell lymphoma, most often presenting as localized disease. Radiotherapy is a curative option, but its proximity to the heart raises concerns about long-term cardiac toxicity, which remains poorly documented. The purpose of this work was to evaluate the potential risk of cardiac toxicity following radiotherapy in patients with pulmonary MALT lymphoma. PATIENTS AND METHODS:This retrospective, population-based study used Surveillance, Epidemiology, and End Results (SEER) data (17 registries, 2000-2022; November 2024 submission). We identified patients with primary pulmonary MALT lymphoma treated with radiation. Demographic and clinical characteristics, including age, sex, Ann Arbor stage, tumour laterality, lobe involvement, and treatment modality, were collected. Outcomes included overall survival, cancer-specific survival, cardiac-specific survival, and non-cancer/non-cardiac-specific survival. Survival estimates were generated using Kaplan-Meier methods; univariate and multivariate Cox models assessed factors associated with cardiac-specific mortality. RESULTS:Among 248 patients, the median age was 70 years; 54.0 % were women and 81.9 % Caucasian. Most had early-stage disease (90.3 %) and right-sided tumours (57.3 %). Radiotherapy alone was used in 86.7 %. With a median follow-up of 59 months, median overall survival was 120 months. At 20 years, overall survival rate was 28.9 %, cancer-specific survival rate 85.5 %, and cardiac-specific survival rate 85.0 %. In competing risk multivariate analysis, age greater than 70 years (hazard ratio [HR]: 10.51; 95 % confidence interval [CI]: 1.11-99.8; p=0.040) and stage III-IV (HR: 6.52; 95 % CI: 1.17-36.4; p=0.032) were independently associated with cardiac-specific mortality. CONCLUSION:Radiotherapy for pulmonary MALT lymphoma is associated with excellent long-term outcomes and low cardiac-specific mortality. Tumour location within the lung does not influence cardiac risk, supporting the absence of significant radiation-induced cardiotoxicity.