Abstract: Objective To investigate the expression of c-Myc in gastric mucosa associated lymphoid tissue (MALT)lymphoma and its implications on prognosis. Methods The clinical data of 79 patients hospitalized in our hospital from 2009 to 2015 were retrospectively analyzed. In these patients, 38 patients were low- grade MALT lymphoma, 20 patients were high-grade MALT lymphoma, 21 patients were diffused large B cell lymphoma (DLBCL). Real-time PCR was used to detect the levels of c-Myc expression in gastric MALT tissues and pair-matched adjacent normal tissues. The relationship between the expression of c- Myc and prognosis of patients was evaluated combing with the clinical data. Results Compared with the normal tissues, the expression levels of c-Myc protein were 15.7% (6/38), 25% (5/20) and 28.5% (6/21)in patients with low-grade MALT lymphoma, high-grade MALT lymphoma, and DLBCL. The relative expression levels of cMyc mRNA were gradually elevated in low-grade MALT lymphoma, high-grade MALT lymphoma and DLBCL. The tumor size and depth of invasion can influence the expression level of c-Myc. Survival analysis found that the overall survival rates and relapse-free survival rates were lower in patients with c-Myc positive expression than those of patients with negative expression (P＜0.05). Conclusion C-Myc plays a key role in the malignant transformation of gastric MALT lymphoma.

Key words: lymphoma, B-cell, marginal zone, stomach neoplasms, genes, myc, prognosis, c-Myc