PURPOSE/OBJECTIVE Radiation-induced lymphopenia has been associated with poor survival outcomes in certain solid tumors such as esophageal, lung, cervical and pancreatic cancers. We aim to determine the effect of treatment-related lymphopenia during radiotherapy on outcomes of patients with oropharyngeal cancer. MATERIALS/METHODS A retrospective analysis of all patients who completed definitive radiotherapy for oropharyngeal cancer at The University of Texas MD Anderson Cancer Center and had blood counts taken during radiotherapy from 2002 to 2013 were included. Patient, tumor and treatment characteristics, clinical outcomes and lymphocyte counts during radiotherapy were recorded. Lymphopenia was graded according to the CTCAE v4.0. Survival rates were estimated using the Kaplan-Meier method and compared with log-rank tests. RESULTS 850 patients were evaluated. The median age was 57 years. The majority of the cohort had p16/HPV-positive disease (71%), 8% had HPV-negative disease and 21% were unknown. The median radiation total dose was 70 Gy. 45% of patients had induction chemotherapy, and 87% had concurrent chemotherapy. 703 (83%) patients developed ≥grade 3 (G3) lymphopenia and 209 (25%) had grade 4 (G4) lymphopenia during radiotherapy. The median follow-up was 59 months; the 5-year overall survival rate was 81%. There were no significant differences in overall survival rates nor in disease control rates, in those who developed G3/G4 lymphopenia compared with those who did not. No significant effect of lymphopenia on survival was observed when analyzed according to p16/HPV status. CONCLUSION In this large cohort of patients with oropharyngeal cancer, the development of lymphopenia during radiotherapy did not impact outcomes.

中文翻译：

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口咽癌患者放疗期间淋巴细胞减少

目的/目的 放射诱导的淋巴细胞减少与某些实体瘤（如食道癌、肺癌、宫颈癌和胰腺癌）的不良生存结果有关。我们旨在确定放射治疗期间治疗相关淋巴细胞减少对口咽癌患者预后的影响。材料/方法 对 2002 年至 2013 年在德克萨斯大学 MD 安德森癌症中心完成口咽癌根治性放疗并在放疗期间采集血细胞计数的所有患者进行回顾性分析。记录放疗期间的患者、肿瘤和治疗特征、临床结果和淋巴细胞计数。淋巴细胞减少症根据 CTCAE v4.0 分级。使用 Kaplan-Meier 方法估计存活率并与对数秩检验进行比较。结果 评估了 850 名患者。中位年龄为 57 岁。大多数队列患有 p16/HPV 阳性疾病 (71%)，8% 患有 HPV 阴性疾病，21% 是未知的。中位辐射总剂量为 70 Gy。45% 的患者接受了诱导化疗，87% 的患者接受了同步化疗。703 (83%) 名患者在放疗期间出现≥ 3 级 (G3) 淋巴细胞减少症，209 (25%) 名患者出现 4 级 (G4) 淋巴细胞减少症。中位随访时间为 59 个月；5 年总生存率为 81%。与未发生 G3/G4 淋巴细胞减少症的患者相比，总体生存率和疾病控制率均无显着差异。当根据 p16/HPV 状态进行分析时，未观察到淋巴细胞减少对存活率的显着影响。结论 在这个大型口咽癌患者队列中，