Correlation between the immunophenotypes, treatment strategies and prognosis of gastrointestinal diffuse large B-cell lymphoma

Objective To explore the differences in the prognosis of patients with different immunophenotypes gastrointestinal diffuse large B-cell lymphoma (GI-DLBCL) who received different treatment strategies. Methods From March 2006 to January 2016, at Nanfang Hospital, Southern Medical University in Guangzhou, the clinical data of 99 patients with pathologically confirmed GI-DLBCL were retrospectively analyzed. According to treatment strategies, patients were divided into chemotherapy alone group and combination of surgery and chemotherapy group. According to immunophenotypes, patients were divided into germinal center B-cell-like (GCB) type and non-GCB type. The two-year progression-free survival (PFS) rate and overall survival (OS) rate were evaluated. Kaplan-Meier analysis, log-rank test and Cox regression were performed for statistical analysis. Results Among the 99 patients with GI-DLBCL, 51 patients were treated with chemotherapy alone, and 48 patients were treated with combination of surgery and chemotherapy. Forty-one cases were GCB phenotype and 40 cases were non-GCB phenotype. The median follow-up time was 25 months. The two-year PFS and OS rates were 70.9% and 89.5%, respectively. The two-year PFS and OS rates of chemotherapy alone group were 63.6% and 85.0%, respectively; both were lower than those of combination of surgery and chemotherapy group (79.4% and 94.7%), and the differences were statistically significant (χ2=4.232, P=0.040 and χ2=4.260, P=0.039). The two-year PFS and OS rates of GCB group were 68.8% and 93.9%, respectively. And the two-year PFS and OS rates of non-GCB group were 73.2% and 85.6%, respectively. There were no statistically significant differences between these two groups (both P>0.05). Among 41 patients with GCB type, 25 were treated with combination of surgery and chemotherapy and 16 were treated with chemotherapy alone. The two-year PFS rate of patients treated with combination of surgery and chemotherapy (83.1%) was higher than that of patients treated with chemotherapy alone (49.2%), and the difference was statistically significant (χ2=5.627, P=0.018). The results of multivariate analysis indicated that treatment strategy was not an independent prognostic factor for all the enrolled patients and in patients with GCB type (all P>0.05). Conclusions Immunophenotypes may lack evaluation value of prognosis in patients with GI-DLBCL. Although among all the enrolled patients and patients with GCB type, the prognosis of patients treated with combination of surgery and chemotherapy is better than that of patients treated with chemotherapy alone, treatment strategy is not an independent prognostic factor. Multi-factors should be evaluated before selection of treatment strategy. Key words: Gastrointestinal tract; Lymphoma, large B-cell, diffuse; Surgery; Chemotherapy; Prognosis