Strong BCL10 Nuclear Expression Identifies Gastric MALT Lymphomas That Do Not Respond to H. pylori Eradication.

Purpose: In a previous retrospective study, we have shown that 75% of gastric MALT lymphomas that did not respond to H. pylori eradication could be identified by detection of t(11;18)(q21;q21). The present study examined the value of t(1;14)(p22;q32) in prediction of the response of gastric MALT lymphomas to H. pylori eradication.

Patients and Methods: A total of 111 patients with H. pylori-positive gastric MALT lymphoma, who were treated by H. pylori eradication, were screened for BCL10 involved chromosome translocation by BCL10 immunohistochemistry, followed by interphase FISH and real-time quantitative reverse transcription PCR (qRT-PCR). The clinical presentation of 11 cases of MALT lymphoma including 6 from the stomach with known BCL10 involved chromosome translocation was reviewed.

Results: Of the 111 cases of gastric MALT lymphoma treated by H. pylori eradication, 75 including 35 from the complete regression group and 40 from the non-responsive group, had adequate specimens for BCL10 immunohistochemistry. Two cases showed strong BCL10 nuclear staining in virtually all tumor cells, similar to that seen in those with t(1;14)(p22;q32). Both were from the H. pylori eradication non-responsive group. Although interphase FISH failed to show evidence of BCL10 gene break or amplification, one case showed an IGH break. This case also showed a high level of BCL10 mRNA expression, compatible to that seen in MALT lymphoma with t(1;14)(p22;q32). 9 of the 11 cases with known BCL10 involved translocation were at stage II_E or above, with three showing agressive clinical presentations.

Conclusion: Gastric MALT lymphomas with strong BCL10 nuclear expression or t(1;14)(p22;q32) are mostly likely resistant to H. pylori eradication.