Multiple primary malignancies in 788 Chinese patients with diffuse large B‐cell lymphoma

Background Diffuse large B‐cell lymphoma (DLBCL) is the most common histological subtype of non‐Hodgkin lymphoma worldwide. The emergence of multiple primary malignancies (MPMs) has been described as a new prognostic factor in many types of tumors. Methods To investigate the morbidity, incidence, and survival of MPM in DLBCL, we retrospectively reviewed the characteristics of 788 patients with DLBCL. Results Forty‐two patients were diagnosed with MPM, and 22 of them were diagnosed with subsequent primary malignancies (SPM) by pathologic biopsy. The incidence of SPM was associated with older age. Germinal center B‐cell‐like (GCB) subtype and earlier Ann Arbor stage DLBCL patients were more prone to SPM. MPM, age, lactate dehydrogenase (LDH) level, Eastern Cooperative Oncology Group performance status (ECOG PS), Hans classification, and international prognostic index (IPI) score were prognostic risk factors for overall survival (OS). Conclusion These data provide a comprehensive view of MPM in DLBCL. MPM was an independent prognostic factor of DLBCL in univariate analysis.