Regression of low-grade gastric mucosa-associated lymphoid tissue lymphoma after eradication of Helicobacter pylori: possible association with p16 hypermethylation.
BACKGROUND
Many reports have stated that the cure of Helicobacter pylori infection can induce a complete remission of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Although p16 hypermethylation was frequently found in MALT lymphoma, the association between this finding and the remission of MALT lymphoma has not been clarified. We performed a prospective study to evaluate the outcome of patients with low-grade gastric MALT lymphoma and the expression of p16 hypermethylation.


METHODS
We prospectively enrolled 20 patients with H. pylori-positive low-grade gastric MALT lymphoma (stage I E1). After the eradication of H. pylori, the patients were regularly followed-up with endoscopic and histological assessment. The methylation-specific polymerase chain reaction (PCR) (MSP) method was used for the serial detection of p16 hypermethylation.


RESULTS
Eighteen patients (90%) achieved complete remission, with a median duration of 15.7 months. The initial detection rate of p16 hypermethylation was 58% (7 of the 12 patients in whom p16 hypermethylation was evaluated successfully). In a serial investigation, 3 patients who were followed-up for a median 28 months showed that the p16 hypermethylation had disappeared.


CONCLUSIONS
Complete remission of low-grade gastric MALT lymphoma after the eradication of H. pylori infection can be maintained for more than 1 year. Further studies are warranted to investigate the role of p16 hypermethylation in the pathogenesis of gastric MALT lymphoma.
Kim
You Sun
YS
Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Korea.
Kim
Joo Sung
JS
Jung
Hyun Chae
HC
Lee
Chang Hee
CH
Kim
Chul Woo
CW
Song
In Sung
IS
Kim
Chung Yong
CY
D000328:Adult; D000368:Aged; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000897:Anti-Ulcer Agents / Q000627:therapeutic use*; D017291:Clarithromycin / Q000627:therapeutic use; D019175:DNA Methylation; D004359:Drug Therapy, Combination; D005260:Female; D015870:Gene Expression; D019942:Genes, p16; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy*; D016480:Helicobacter pylori; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000188:drug therapy / Q000235:genetics* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000627:therapeutic use; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D012074:Remission Induction; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000382:microbiology*; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole