Treatment of Parotid Non-Hodgkin Lymphoma: A Meta-Analysis

PURPOSE: This meta-analysis aimed to review the published outcomes of parotid non-Hodgkin lymphoma (NHL) pertaining to different treatment modalities. MATERIALS AND METHODS: A total of 48 journal articles published between 1993 and 2015, comprising 742 cases of parotid NHL, were initially evaluated. In total, 108 patients from 12 studies who had sufficient data for analysis, including age, tumor histopathology, treatment modality, and outcome at final follow-up, were included. Patients were randomly assigned to different categories on the basis of histopathology and treatment modality. Groups were compared using Kaplan-Meier survival curve analysis and the Mann-Whitney U test. RESULTS: Log-rank tests demonstrated that for early-stage (I and II) parotid NHL of all histopathology variants, radiation therapy significantly improved the survival rate versus chemotherapy (P = .043), as well as combined treatment with chemotherapy and radiation therapy (P = .023). For early-stage diffuse large B-cell lymphoma, combined treatment significantly improved survival versus single treatment (P = .028). No treatment was received by seven patients with early-stage mucosa-associated lymphoid tissue lymphoma after undergoing parotidectomy. When the clinical outcomes of these patients were compared with those of other patients with the same histology who underwent further treatment, no significant differences were noted in survival outcomes. CONCLUSION: Radiation therapy seems to be a valid treatment of early-stage parotid NHL. However, for diffuse large B-cell lymphoma, survival was higher with combined treatment versus single treatment. For early-stage parotid mucosa-associated lymphoid tissue lymphoma, complete excision of the tumor through superficial parotidectomy may have similar survival outcome.