Metachronous gastric cancer following complete remission of gastric MALT lymphoma

Recently, there have been some reports on the long-term clinical outcome of gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma) [1]. Localized gastric MALT lymphoma generally has a favorable prognosis; however, metachronous gastric cancers developed during our long-term follow-up. Two men were diagnosed with Helicobacter pylori-positive gastric MALT lymphoma and were classified as grade I and grade II1 according to the Rugano classification. Both patients achieved complete remission in 3 months after eradication therapy and have maintained this state. However, yearly followup endoscopy showed early-stage depressed-type gastric cancer at 5 and 8 years after remission of the lymphoma. Both carcinomas were resected by endoscopic surgery. One woman received radiation therapy (whole dose 30 Gy) to treat localized gastric MALT lymphoma, classified as grade II1. She was negative for H. pylori infection since she had been diagnosed as having MALT lymphoma 11 years ago. At the fifth year after radiation therapy, regular endoscopy revealed an early gastric cancer in the corpus, which was cured by endoscopic surgery. All three cases have maintained complete remission of the gastric MALT lymphoma but developed intestinal-type gastric cancer in the same areas where the MALT lymphoma had been eradicated. It is controversial whether gastric cancer risk is increased in patients with gastric MALT lymphoma, and there have been few reports on metachronous gastric cancer in patients, following remission of gastric MALT lymphoma [2].