Chin Med J (Taipei) 1998;61:S119.

High-grade Gastric MALT Lymphoma - Can It Be Controlled by Anti-H. Pylori Therapy?

Ann-Lii Cheng, M.D., Ph.D.

Associate Professor, Department of Internal Medicine and Department of Oncology, National Taiwan University Hospital. No. 7, Chung-Shan South Rd., Taipei, Taiwan.

Abstract

Although it has been documented that eradication of H.pylori (HP) results in regression of 60-80% of low-grade gastric MALT lymphoma (MALToma), the situation in high-grade gastric MALToma (HGGM) is less clear. In-vitro study by Hussell et al indicated that lymphoma cells from HGGM do not respond to H.pylori stimulation. A clinical study by Bayerdorffer et al revealed that most anti-HP-refractory gastric low-grade MALTomas contain occult high-grade components. These evidence suggested that HGGM is an autonomously growing tumor which is very unlikely to respond to HP eradication therapy. However, we and other investigators have observed in HGGM patients who refused chemotherapy sporadic but unequivocal tumor regression after HP eradication. A prospective study is mandatory.

In the past 3 years, 8 patients with stage IE HGGM who had consented to a brief trial of antimicrobial therapy were enrolled onto this pilot study. HGGIVI was diagnosed as a predominance of high-grade lymphoma with residual low-grade foci, or the presence of clusters or sheets of transformed blast cells within the low-grade centrocyte-like cell infiltrate. Standard antimicrobial therapy for HP were given. Patients were followed up by endoscopic examination every 4-6 weeks. On each occasion, at least 4 biopsies were taken from antrum and body for evaluation of HP, and at least 6 biopsies were taken from the tumorous and suspicious areas for evaluation of the tumors.

Eradication of H.pylori was achieved in 7 patients, of whom 5 (71.4%) were then followed by complete histologic remission (<= grade 11 of Worthorspoon's scoring system) of their HGGM. Four of the 5 responders showed first evidence of tumor regression within 6 weeks of the completion of anti-HP therapy. The depth of tumor invasion, as documented by endoscopic ultrasound examination, and the proportion of large-cell component, did not affect the response. All 5 responders remain in remission at this resport (27, 12, 7, 6, and 6 months after starting anti-HP therapy, respectively).

We conclude that a substantial portion of early-stage HGGM can still be controlled by HP eradication therapy. However, the quality of remission remains to be determined by longer duration of follow-up.

[Chin Med J (Taipei) 1998;61:S119.]