Long-term Outcomes of Early-stage Non-stomach Gastrointestinal Mucosa-associated Lymphoid Tissue Lymphoma Treated With Radiation Therapy

Non-stomach gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma is rare, and there are only a few reports regarding radiation therapy (RT) for non-stomach gastrointestinal MALT lymphoma. There has been no established cure and no reports on RT use with long-term follow-up. Herein, we report a retrospective long-term investigation of early-stage non-stomach gastrointestinal MALT lymphoma. Our aim was to evaluate whether RT is a valid treatment option for this disease.We retrospectively analyzed 6 patients who were diagnosed with early-stage non-stomach gastrointestinal MALT lymphoma and received RT. The median age was 66 years (range=38-89 years). The primary tumor originated from the duodenum in 2 patients and from the rectum in 4 patients. The RT dose was 30-34 Gy in 15-20 fractions to the involved site or field, depending on the case.The median follow-up time was 89.5 months (range=6-170). All patients had complete remission within 3 months after RT. The 5-year overall survival and progression-free survival rates were 83.3% and 100%, respectively. During the observation period, no patient had a confirmed recurrence. One patient died of causes unrelated to cancer or treatment. There were no late toxicities by RT.Our results show good long-term local control and no late toxicities requiring treatment. Moderate-dose RT was appropriate and well tolerated for early-stage non-stomach gastrointestinal MALT lymphoma.