Long Term Outcome of Gastric MALT Lymphoma Patients Treated with Anti-Helicobacter (Antibiotic and Proton-Pump Inhibitor) Regimens.

Background: Primary mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach is often associated with Helicobacter pylori (Hp) infection and Hp eradication therapy is widely accepted as initial treatment. The aim of this study is to report the clinical characteristics and long term outcome in a large series of patients with gastric MALT lymphoma exclusively treated with Hp eradication therapy.

Methods: 105 newly diagnosed gastric MALT lymphoma patients (54 men and 51 women) with median age of 64 years (range 20–94) referred to our institutions between June 1990 and November 2006 were eligible for the study. Staging was performed according to the Lugano staging system. All patients received anti-Hp eradication therapy as initial treatment with standard regimens combining antibiotics (usually Amoxicillin, Clarithromycin and/or Metronidazole) and proton-pump inhibitors (Omeprazole in most cases). Responses, evaluated with regular endoscopic biopsies every 3–6 months were graded according to the Wotherspoon’s histological score system.

Results: 100 patients had stage I and 5 patients had stage IIE1 disease. Hp was positive in 83 patients (79.5%) and was eradicated in all positive patients but 19 patients required a second line antibiotic therapy. Symptoms disappeared or markedly diminished and endoscopic features improved in almost all patients after Hp eradication. Histological regression of the gastric lymphoma was achieved in 78 of 102 evaluable patients (76%, 95% C.I.; 67%–84%) with histological complete response (Wotherspoon’s score 0–2) in 66 and partial response (score 3) in 12 patients. Of the 78 patients who achieved a lymphoma regression, the histological remission was consistently confirmed at follow-up endoscopies in 28 patients (36%), while 33 (42%) had histological score fluctuations (from 0–4), sometimes with transient histological relapses followed by spontaneous histological remissions. Ten patients had a frank lymphoma relapse (2 with high-grade transformation) and 7 died in remission for other causes. At a median follow up time of 6.3 years, the overall survival in the entire group is 92% at 5 years (95% C.I.; 84%–96%), 83% at 10 years (95% C.I.; 70%–91%) and 78% at 15 years (95% C.I.; 62%–88%). Only one patient died for lymphoma (after histological transformation). Additional tumors were observed in 22%. A history of autoimmune disease was present in 15% of the patients and did not affect the outcome.

Conclusions: Hp eradication usually results in long term disease control, independently of the lymphoma pathological remission status. A watch and wait policy seems safe in patients with local histological relapse with no endoscopic evidence of gross disease.