As many as 80% of gastric MALT lymphoma patients achieve remission after Helicobacter pylori eradication, yet these patients remain at a significantly increased risk for second gastric cancers and lymphomas, reported Dr. Thomas Wündisch and his colleagues in Gastroenterology.
"The clinical consequence of this should be yearly lifelong endoscopic follow-up in all patients with a history of GML [gastric MALT lymphoma] to detect gastric cancer as early as possible," they wrote.
Dr. Wündisch, of Heinrich-Heine-Universität in Düsseldorf, Germany, and his colleagues studied 120 patients (63 female, mean age 62 years) recruited between June 1993 and July 1999 with stage EI1 gastric mucosa–associated lymphoid tissue (MALT) lymphoma according to the Ann Arbor system, where lymphoma is limited to the mucosa and submucosa of the stomach with no lymph node involvement.
Patients in this multicenter study underwent H. pylori eradication therapy consisting of a 2-week course of amoxicillin (750 mg three times daily) and omeprazole (40 mg three times daily).
Endoscopy was performed monthly until complete histologic remission, defined as macroscopic disappearance of lymphoma and absence of lymphoma on biopsy in two consecutive analyses, and then every 6-12 months. Patients were followed for a median of 122 months after H. pylori eradication (range, 1-171 months).
Dr. Wündisch and his colleagues reported that 96 of the 120 patients with complete follow-up (80%) achieved complete GML remission between 1 and 28 months after eradication therapy began, and 80% of them (77/96) remained disease free (Gastroenterology 2012 [doi: 10.1053/j.gastro.2012.06.035]).
Histologic residual disease was seen in 16 out of 96 patients; indeed, it was likely "ongoing histological residual disease rather than complete remission, as the microscopic lesions were small and often found only upon examination of serial sections of one of multiple biopsies."
A "watch and wait" approach was used in these cases, and all but one patient showed complete remission again at the last time point, with a median second remission duration of 46 months. There was also no progression.
"We strongly support this strategy," the investigators wrote.
Overall, the 96 patients with complete GML remission had a 5-year survival rate of 94%, and a 10-year survival of 87%.
Nevertheless, the researchers observed a morbidity ratio of 8.567 for gastric cancer among these patients (95% confidence interval, 3.566-20.582; P less than .001) and 18.621 for non-Hodgkin’s lymphoma (95% CI, 8.365-41.448; P less than 10–6), compared with the general population. The morbidity rate for all cancers was also elevated, at 1.689, but this was not statistically significant.
According to the researchers, although treatment-related factors often contribute to the development of second cancers in patients with lymphoma, the 2-week-long H. pylori regimen employed was unlikely to cause long-term toxic effects.
"Patient-related factors, such as gene polymorphisms, might play a more important role in the development of GML and second cancers in our patients, but these factors have yet to be identified," they said.
In any case, "currently, follow-up of patients without significant comorbidities should extend beyond 5 years for detecting reinfection, relapse, second lymphoma, and early gastric cancer."
The authors stated that the study was funded by a grant from Deutsche Krebshilfe, and they had no personal disclosures.
