Comparison of survival outcomes of different treatment modalities for patients with primary splenic diffuse large B cell lymphoma

Primary splenic diffuse large B cell lymphoma (DLBCL) is one of the most common primary tumors in the spleen, while its prevalence is relatively low. Recently, there has been an increase in the incidence rate of primary splenic DLBCL; however, the effectiveness of various treatments for it has not been adequately described previously. The purpose of this study was to compare the effectiveness of various treatments on survival time in primary splenic DLBCL. A total of 347 patients with primary splenic DLBCL were enrolled in The Surveillance, Epidemiology, and End Results (SEER) database. These patients were subsequently divided into four subgroups according to the treatment modalities: non-treatment group (patients who had not received chemotherapy, radiotherapy, or splenectomy, n=19), splenectomy group (patients who had received splenectomy only, n=71), chemotherapy group (patients who had received chemotherapy only, n=95), and the splenectomy combined with chemotherapy group (patients who had received splenectomy and chemotherapy, n=162). The overall survival (OS) and cancer specific survival (CSS) of four treatment groups were evaluated. Compared to the splenectomy group and the non-treatment group, the OS and CSS of the splenectomy combined with chemotherapy group was extremely significantly prolonged (P<0.01). Compared with the chemotherapy group, the OS and CSS of the splenectomy combined with chemotherapy group were longer, but there was no statistical difference (P>0.05). The Cox regression analysis showed that the treatment modality was identified as an independent prognostic factor for primary splenic DLBCL. The landmark analysis shows that the overall cumulative mortality risk was significantly lower in the splenectomy combined with chemotherapy group than in the chemotherapy group within 30 months (P<0.05), and the cancer-specific mortality risk was significantly lower in the splenectomy combined with chemotherapy group than in the chemotherapy group within 19 months (P<0.05). Splenectomy combined with chemotherapy may be the most effective treatment modality for primary splenic DLBCL.