Abstract: Objective　To investigate the clinical characteristics and prognosis of patients with B-cell secondary non-Hodgkin lymphoma (sNHL). Methods　From January 2007 to May 2018，among the NHL patients treated in our hospital, 1.65% (47/2 853) appeared in the form of a second malignant tumor, of which 44 cases were B-cell sNHL. The treatment of the first primary malignant tumor in 44 sNHL: 29 cases accepted surgical resection, 10 cases received surgery combined with chemotherapy, 2 cases received surgery combined with radiotherapy, and 3 cases received surgery combined with chemotherapy and radiotherapy. The treatment of secondary lymphoma: 34 patients received chemotherapy, 5 patients received chemotherapy combined with surgery, 4 patients received radiotherapy for extranodal primary sites or massive masses, one patient received the treatment of anti-helicobacter pylori eradication since the extracellular nodal marginal zone B-cell lymphoma and mucosa-associated lymphoid tissue lymphoma (gastric type). The median time of chemotherapy was 6 (2, 8) months. Patients with CD20+ DLBCL or CD20+ FL that were stage Ⅲ to Ⅳ were infused with rituximab (375 mg/m2) intravenously one day before chemotherapy. The median follow-up time was 11.4 (0.5, 145.3) months. Results　For the 44 sNHL patients, breast cancer (n=10) was the most common type of primary malignancies before NHL. The most common type of NHL was diffuse large b-cell lymphoma (DLBCL, n=29). For 44 sNHL patients, 65.9% (29/44) patients were diagnosed the first primary tumor at age ＜60 years, and 59.1% (26/44) patients were diagnosed with sNHL at age ≥60 years. The median survival time without a second tumor was 63.4 (25.2, 146.9) months. The median follow-up time of 44 sNHL was 11.4(4.2, 28.8) months, and the average disease-free survival (DFS) time was 9.6 (4.1, 26.0) months. The 3-year overall survival (OS) was 73.5%. The complete remission rate (CR) was 38.6% after first-line treatment, and the overall response rate (RR) was 63.6%. The 3-year overall survival rates were 81.1% and 66.5% for patients received rituximab and patients without rituximab (Log-rank χ2=2.026, P＞0.05). Univariate analysis showed that the diagnosis age of the first primary malignant tumors was ≥60 years old (Log-rank χ2=7.562, P＜0.05) and the diagnosis age of sNHL was ≥60 years old (Log-rank χ2=4.887, P＜0.05) suggesting a poor prognosis. Multivariate analysis further demonstrated that the diagnosis age of the first primary malignant tumors ≥ 60 years old (HR=4.745，95%CI：1.405-16.020) was an independent risk factor affecting the survival rates of sNHL patients. Conclusion　The diagnosis age of the first primary cancer ≥ 60 years old will increase the risk of death in sNHL patients. 

Key words: lymphoma, non-Hodgkin, lymphoma, B-cell, neoplasms, multiple primary, neoplasms, second primary, survival analysis, prognosis