Radiotherapy is associated with improved survival in stage I-II gastric MALT lymphoma after failed or inadequate eradication: a single-center retrospective study.

[OBJECTIVE] To investigate the impact of different first-line anti-tumor therapies on survival outcomes in patients with stage I-II gastric MALT lymphoma who failed or did not receive anti- () therapy.

[METHODS] Clinical data from 144 patients with anti- therapy-failed or -naïve stage I-II gastric MALT lymphoma treated at Sun Yat-sen University Cancer Center between June 1998 and July 2021 were retrospectively analyzed. Patients were divided into three groups based on first-line treatment: systemic therapy alone radiotherapy alone, and radiotherapy combined with systemic therapy. Kaplan-Meier analysis and log-rank tests were used to compare progression-free survival (PFS) and overall survival (OS) among groups. Univariate and multivariate Cox regression analyses were performed to identify independent prognostic factors.

[RESULTS] Significant differences were observed among the three groups regarding staging, H. pylori status, prior anti-H. pylori therapy, elevated LDH, Ki67%, and CD20+ expression (p < 0.05). With a median follow-up of 59 months (IQR: 35-101 months), the radiotherapy-alone group (n = 56) demonstrated superior PFS (p = 0.001), and OS (p = 0.031) compared to the systemic therapy-alone group (n = 39). No significant differences in PFS (p = 0.358) or OS (p = 0.386) were observed between the radiotherapy-alone and combined therapy groups (n= 49). Stratification by radiotherapy dose (≤30 Gy, 31-35 Gy, 36-42 Gy) revealed no survival differences (p > 0.05). Univariate analysis identified low LDH, low MALT-IPI score, prior anti-H. pylori therapy, and radiotherapy (alone or combined) as protective factors against recurrence (p < 0.05). However, multivariate analysis confirmed only radiotherapy (alone or combined) as independent predictors of reduced recurrence (p < 0.05).

[CONCLUSION] Radiotherapy remains the highly effective option for anti-H. pylori therapy-failed or -naïve stage I-II gastric MALT lymphoma. Combined therapy provided no additional survival benefit over radiotherapy alone. Notably, prior (even failed) anti-H. pylori therapy may reduce recurrence risk, warranting further validation.