Abstract: Background and purpose: Head and neck diffuse large B-cell lymphoma (HN-DLBCL) is one of the most common aggressive non-Hodgkin's lymphoma involving this anatomical site. With the clinical application of rituximab-containing immunochemotherapy and local radiotherapy as well as cellular immunotherapy, treatment outcomes of HN-DLBCL patients, including not only rates of response, but also progression-free survival (PFS), have been dramatically improved. However, a number of patients become relapsed/refractory cases. Previous clinical studies showed that risk-adapted treatment strategies could allow prompt and tailored intervention for high-risk patients thereby significantly reducing probabilities of being relapsed or refractory cases. The present study aimed to systematically analyze clinical features and their prognostic values in HN-DLBCL patients and compare stratification efficacies of different prognostic models. Methods: A total of 134 patients with HN-DLBCL in Shanghai Ninth People’s Hospital from Jan. 2010 to Dec. 2018 were retrospectively identified and systemically analyzed. Survival curves were estimated by using Kaplan-Meier survival methodology. The prognostic influences of clinical factors on survival were studied by univariate log-rank test and multivariate Cox proportional hazards regression models. Three prognostic models including International Prognostic Index (IPI), National Comprehensive Cancer Network-IPI (NCCN-IPI) and Spanish Lymphoma/Autologous Bone Marrow Transplant Working Group-IPI (GELTAMO-IPI) were applied for risk stratification to compare 3-year survival rates among patients in different risk groups. Results: Univariate analysis identified prognostic factors for HN-DLBCL patients, including Ann Arbor stage, non-germinal center B-cell (non-GCB) subtype, serum lactate dehydrogenase (LDH) and β2 microglobulin value, while multivariate Cox regression analysis revealed that serum LDH level was the independent prognostic indicator. The predicted 3-year overall survival (OS) of high-risk HN-DLBCL patients stratified by IPI, NCCN-IPI and GELTAMO-IPI were 44.7%, 36.8% and 32.8%, while their 3-year PFS were 44.3%, 20.7% and 16.3%, respectively. NCCN-IPI and GELTAMO-IPI demonstrated enhanced discrimination compared with IPI for high-risk HN-DLBCL cases ［3-year PFS (IPI vs NCCN-IPI vs GELTAMO-IPI): 44.3% vs 20.7% vs 16.3%］. Conclusion: In immunochemotherapy era, LDH level was an independent prognostic factor in HN-DLBCL patients. Modified prognostic models including NCCN-IPI and GELTAMO-IPI might be more powerful than IPI in predicting high-risk patients.

Key words: Diffuse large B-cell lymphoma, Head and neck, Prognosis, Survival rate