Development and validation of prognostic scoring in primary intestinal diffuse large B-cell lymphoma: a single-institution study of 184 patients.

Background The incidence of primary intestinal diffuse large B-cell lymphoma (PI-DLBCL) is much lower than primary gastric DLBCL, and large-scale analyses on the clinical characteristics, molecular features, therapeutic strategies, and risk stratification have been seldomly performed in PI-DLBCL. Methods To assess prognostic model development, 107 PI-DLBCL patients diagnosed before 2014 were studied for prognosis factors including different primary involved sites and treatment strategies. For internal validation, a non-random split sample set with 77 PI-DLBCL patients after 2014 was included for validation of the prognosis factors. Results Patients with an ileocecal lesion presented with better survival time than those with non-ileocecal sites, with surgical resection significantly influencing the prognosis. Non-ileocecal patients who underwent surgery with lymphadenectomy had superior overall survival (OS) and progression-free survival (PFS) compared to those receiving surgery without lymphadenectomy or those not receiving (without) surgery. For ileocecal patients, surgery with or without lymphadenectomy resulted in better OS and PFS than those without surgery. For biomarker analysis, only BCL-2 >50% or Ki67 >80% on tumor cells indicated poor clinical outcome. In multivariate analysis, age, Eastern Cooperative Oncology Group (ECOG) score, and site of origin were independent prognostic factors for inferior OS in PI-DLBCL. A prognosis model was set up based on age, ECOG score, and site of origin, and validated well. Conclusions The prognosis in patients with PI-DLBCL with ileocecal involvement showed was better than those with non-ileocecal involvement. Surgical strategy can impact the clinical outcome of PI-DLBCL patients.