Metachronous gastric MALT lymphoma and early gastric cancer.

In a recent paper published in this journal, Copie-Bergman et al. [1] presented four cases of metachronous early gastric cancer developing after gastric MALT lymphoma. In these patients, they found (minimal) residual lymphoma in all surgical specimens, suggesting that such patients might have an increased risk for the development of early gastric cancer. Three of their patients had undergone prolonged therapy with an oral alkylating agent and three were found to be positive for t(11;18) (q21;q21). While the presence of residual lymphoma in all four patients is intriguing, it does not necessarily implicate an increased risk for metachronous gastric cancer, and in our opinion a note of caution should be added when interpreting these findings. As opposed to the findings reported by the authors, we have observed three patients developing early gastric cancer after prolonged complete remission (CR) of gastric MALT-lymphoma, of which two have previously been published [2]. In these three cases, gastric cancer restricted to the mucosa was diagnosed at a time span of 9–56 months after treatment of the lymphoma. One patient had been treated with eradication of Helicobacter pylori and achieved a CR of the lymphoma, while the other two cases did not respond to Helicobacter pylori eradication within a time span of 12 months and were given therapy with 2CdA. Early gastric cancer was diagnosed during routine follow-up endoscopy in all three patients and histology disclosed features of signet ring cell carcinoma in two of them. All patients underwent partial gastrectomy and histologic assessment of the gastrectomy specimens disclosed no evidence of residual gastric MALT-lymphoma. Analysis of resected lymph nodes, as well as CT-scan performed prior to resection, found no evidence of carcinoma dissemination. Interestingly, both patients with signet ring cell-type had a history of underlying Sjogren’s syndrome and were negative for t(11;18) (q21;q21), while the patient with early adenocarcinoma was positive for t(11;18) (q21;q21) but had no signs of an autoimmune condition. As opposed to the findings by Copie-Bergman [1], two of our patients died from liver metastases, including one patient with signet ring cell histology. Metastases developed 25 and 12 months after resection of the early gastric cancer. These findings demonstrate that metachronous early gastric cancer does not necessarily have to be associated with residual lymphoma and that one should be cautious when suggesting residual disease as a risk factor for gastric cancer. In fact, the patients developing gastric cancer showed additional features which might constitute risk factors, such as the presence of autoimmune disease, t(11;18) (q21;q21) or prior chemotherapy. In view of the apparently excellent outcome in patients remaining in minimal residual disease after treatment for MALT lymphoma [3], clinicians should not subject patients with minimal residual disease to aggressive (over-)treatment in the absence of a clear definition of this condition as a risk factor for consecutive malignancy. M. Raderer*, B. Streubel, S. Wöhrer & A. Chott Division of Oncology and Department of Pathology, Department of Internal Medicine I, Medical University Vienna, Vienna, Austria (*E-mail: markus.raderer@meduniwien.ac.at)