Clinical features and prognosis of double primary malignant neoplasms in patients with non-hodgkin lymphoma

To investigate the clinical features, survival, and prognostic factors of patients with double primary malignant neoplasms (DPMNs) comprising non-Hodgkin lymphoma (NHL) and malignant solid tumors. Of the 2352 patients diagnosed with NHL, 105 (4.46%) patients were diagnosed with DPMNs, 42 (40.0%) had NHL first (the NHL-first group) and 63 (60.0%) had solid tumor first (the ST-first group). Females were more frequent in the ST-first group, and the interval time between the two tumors was longer. More NHLs in early stages and originating from extranodal sites were observed in the NHL-first group. Male, age ≥ 55 years at diagnosis of the first tumor, interval time <60 months, NHL diagnosed first, NHL arising from an extranodal site, DPMNs without breast cancer, and no surgery for the first primary tumor were associated with poorer overall survival (OS). Interval time <60 months and NHL diagnosed first were independent risk factors that affected the prognosis of patients with DPMNs. Therefore, careful monitoring and follow-up are especially important for these patients. 50.5% (53/105) of patients with DPMNs did not receive chemotherapy or radiotherapy prior to the diagnosis of the second tumor. We further compared the baseline characteristics of diffuse large B-cell lymphoma(DLBCL) patients with and without solid tumors, the former had a higher proportion of extranodal DLBCL, suggesting that extranodal DLBCL is more likely to develop solid tumors than nodal DLBCL.