Second primary malignancies in patients treated for gastric mucosa-associated lymphoid tissue lymphoma.

To assess the risk of second primary malignancy (SPM) in patients with gastric mucosa-associated lymphoid tissue (MALT) Lymphoma (GML), we included 175 patients with GML in the present study. The incidence of SPM in the general population, used for reference, was determined from the French network of cancer registries. During the 1442.9 patient-years of follow-up, 29 patients were diagnosed with incident SPM, including five patients diagnosed with gastric cancer (20.1/1000 patient-years). An increased incidence of SPM was observed in patients with GML (standardized incidence ratios [SIR]: 1.71 [1.14-2.45]) compared to the general French population especially for gastric cancer (SIR: 16.1 [5.19-37.56]). This elevated risk of SPM was significantly increased only in patients treated with immuno/chemotherapy but not in patients treated with Helicobacter pylori eradication alone. Long-term follow-up of patients with GML is mandatory even in patients who have achieved complete remission.