Prospective Study of Frontline H Pylori Eradication in the Treatment of Early-stage Extragastric MALT Lymphoma

Gastric low-grade mucosa-associated lymphoid tissue lymphoma (MALToma) is associated with Helicobacter pylori (HP) infection, and around 70% of these tumors can be cured by HP eradication therapy (HPE). However, the role of antibiotics in the frontline treatment of extragastric MALToma remains unclear. In addition to anecdotal case reports showing histologic regression of extragastric MALTomas after antibiotics, our explorative study found that frontline HPE (clarithromycin, amoxicillin, and omeprazole) resulted in complete remission (CR) in this subgroup patients (2 salivary gland, 1 lung, 1 colon, and 4 ocular adnexal MALToma \[OAML\]). Interestingly, two patients with OAML who do not respond to Chlamydia psittaci (CP) eradication using doxycycline achieved CR after HPE. These findings suggest that bacterial infections, including HP, may be involved in the lymphomagenesis of these extragastric MALTomas. Our preliminary results also revealed that 5 (23.8%) of 21 HP-negative gastric MALToma patients achieved CR after HPE, indicating that antibiotics may also have ability to eradicate non-HP bacteria. Based on our preliminary findings and the indolent biologic behavior of MALToma, it is reasonable to use frontline HPE in the treatment of early-stage low-grade extragastric MALToma.