Xin Liu

Department of Radiation Oncology, Cancer Hospital and Institute, Peking union   Medical College (PUMC) and Chinese Academy of Medical Sciences (CAMS)

Objective:Few studies have directly compared the efficacy and safety of radiotherapy with other therapeutic approaches in early-stage gastric mucosa-associated lymphoid tissue (MALT) lymphoma. This retrospective study compared treatment outcomes and toxicities between radiotherapy and other oncological treatment modalities for early-stage gastric MALT lymphoma. Method: From June 2000 to December 2012, 61 consecutive patients with newly diagnosed stage I (n=29) and II (n=32) gastric MALT lymphoma were reviewed. Twenty patients (33%) received initial radiation therapy: 12 had chemotherapy followed by radiotherapy, 5 patients had radiotherapy alone, 2 patients had surgery and chemotherapy followed by radiotherapy, and 1 patient had surgery followed by radiotherapy. Forty-one patients did not receive radiotherapy: 25 had surgery plus chemotherapy, 8 had chemotherapy alone, and 8 had surgery alone. The median radiation dose was 36 Gy (range, 22.4-45 Gy). The first-line chemotherapy was RCHOP/CHOP or CHOP-like regimens (median, 5 cycles; range, 1-7). Overall survival (OS), progression-free survival (PFS), and locoregional control (LRC) rates were calculated using the Kaplan-Meier method and compared using log-rank test. The clinical features and treatment toxicities of the different subgroups were compared using chi-square analysis. Result: The median follow-up time was 88 months (range, 5-169 months). Initial radiotherapy significantly improved complete response (CR) rate compared with initial chemotherapy (92.3% versus 40%, P=0.003). The 5-year OS, PFS, and LRC rates were 83.6%, 66.7% and 78.7%, respectively. Patients treated with initial radiotherapy had higher 5-year OS (100% versus 74.8%, P=0.009), PFS (85% versus 57.3%, P=0.024) and LRC (95.0% versus 69.9%, P=0.040) rates than those treated without. Rates of grade 4 or higher acute toxicities were statistically lower in radiotherapy group (0% versus 26.0%, P=0.029). No serious late complications were observed in all patients during the long-term follow up. Conclusion:Considering long-term efficacy and safety, moderate-dose radiotherapy should be suggested as an optimal nonantibiotic treatment for early-stage gastric MALT lymphoma.

Key Words: Mucosa associated lymphoid tissue lymphoma  radiotherapy