Background & objective: Primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL) is difficult to be distinguished from other gastrointestinal tumors because of its onset sites and clinical features, which results in frequent misdiagnoses. The standard chemotherapy regimen for PGI-DLBCL is uncertain. This study was to analyze the clinical characteristics, cell origin, and prognosis of PGI-DLBCL, and explore effective combined chemotherapy for PGI-DLBCL.
Methods: Clinical data of 40 PGI-DLBCL patients, diagnosed and treated in Peking University Third Hospital from 1998 to 2007, were analyzed by Kaplan-Meier method, log-rank test, and Cox regression model. The cell origins of PGI-DLBCL in 34 patients were analyzed by immunohistochemistry. The patients were treated with combined chemotherapy, surgery plus combined chemotherapy and/or radiotherapy, or surgery alone. The combined chemotherapy included CHOP and CHOP-like regimens.
Results: The median age of the 40 patients was 56.5 years. The ratio of sex (male:female) was 1.86:1. The ratio of onset sites (gastric versus intestinal) was 1.05:1. Among the 38 patients who had been followed up, 12 (31.6%) died, both the 3-and 5-year overall survival rates were 64.7%. Of the 9 patients with multiple sites involvement, 8 (88.9%) died within 3 years after diagnosis. Of the 34 patients received immunohistochemical examination, 9 (26.5%) had lymphomas of germinal center origin, and 25 (73.5%) had non-germinal center origin. Log-rank test revealed that International Prognostic Index (IPI) score and B symptom were important prognostic factors of PGI-DLBCL. Cox multivariable analysis showed that the death risk of the patients with high level of LDH was 2.87 times higher than that of the patients with normal level of LDH.
Conclusions: PGI-DLBCL is often seen in male patients at middle ages. Multiple sites involvement is an important death cause of these patients. Tumor cell origin, IPI score and B symptom are important prognostic factors of PGI-DLBCL. The serum level of LDH at diagnosis is an independent prognostic factor.