We generally agree with Montalban and associates' comments. We have now treated more than 40 patients with antibiotics, confirming in more cases that histologic regression of localized low-grade MALT lymphoma can be achieved in more than 60% of patients after eradication of Helicobacter pylori [1].

Histologic assessment remains, in our opinion, the pivotal method for treatment evaluation, given that molecular analysis is not yet widely available; moreover, the clinical significance of molecular remission remains controversial in other low-grade lymphomas (for example, Bcl-2 rearrangement monitoring in follicular lymphoma) [2]. However, we have done molecular studies (PCR detection of IgH gene rearrangement) in some of our patients before and after anti-Helicobacter therapy and have observed that monoclonal rearrangements of the immunoglobulin genes are no longer detectable in most patients who achieve histologic remission of low-grade gastric lymphoma (Unpublished data). The currently available information therefore seems to indicate that molecular studies should be mandatory in clinical trials of low-grade gastric MALT lymphoma, as Montalban and associates advocate. However, only time will tell whether antibiotics can achieve permanent healing and whether molecular analysis is superior to histologic studies in predicting outcome.

Uniformity in the diagnostic criteria and in the histologic assessment of response is also needed to compare different clinical trials, and we welcome a wider and more consistent use of the histologic scoring for low-grade gastric MALT lymphoma that Wotherspoon and colleagues proposed [3]. Treatment of relapses after antibiotics is one of the many open questions in the treatment of gastric lymphoma [4], and it is currently impossible to give definitive recommendations regarding the need for surgery or use of chemotherapy. Retrospective studies show that surgery can certainly be curative in patients with localized disease. We believe that total radical gastrectomy would be the only adequate surgical approach because of the known multifocality of MALT lymphoma and the risk for relapses in the gastric remnant, but this procedure carries a considerable risk for death and long-term illness. In our retrospective review of 83 cases of low-grade gastric MALT lymphoma, we observed no differences in outcome among patients treated with surgery, chemotherapy, or antibiotics [1]. However, the major cause of death in our series was additional tumors. The incidence of these tumors was unexpectedly high: 17 of 83 patients (20%). In this group, 9 of 83 patients have died, 8 of whom had a second solid tumor [5].