Prognostic factors in oropharyngeal squamous cell carcinoma in the state of São Paulo, Brazil: 10-year follow-up

Abstract Objective: To descriptively analyze the epidemiological data, clinical stage, and outcomes of oropharyngeal squamous cell carcinoma in the state of São Paulo, Brazil, and to estimate the influence of clinical stage and treatment type on overall and disease-free survival. Methods: We retrospectively analyzed epidemiological data from the São Paulo Cancer Center Foundation database relative to patients with oropharyngeal squamous cell carcinoma diagnosed between 2004 and 2014 in the state of São Paulo. Univariate and multivariate Cox regression analyses were performed to assess factors associated with the outcomes. A forward stepwise selection procedure was used. Survival curves were estimated by the Kaplan-Meier method and compared by the Gehan-Breslow-Wilcoxon test. Results: A total of 8075 individuals with oropharyngeal squamous cell carcinoma were identified. Of these, 86.3% were diagnosed at an advanced stage and 13.7% at an early stage. Only 27.2% of patients were treated surgically, whereas 57.5% were treated medically. Patients undergoing surgery had longer overall survival than those receiving medical treatment in both early- and advanced-stage oropharyngeal squamous cell carcinoma. However, there was no significant difference in disease-free survival between surgical and medical treatment. Conclusion: No significant difference in disease-free survival between medical and surgical treatment suggests similar complete remission rates with both approaches. Patients receiving medical treatment had shorter overall survival, which may be due to complications from chemotherapy and radiotherapy. However, we cannot confirm this relationship based on the data provided by the São Paulo Cancer Center Foundation. Prospective studies are warranted to assess whether the lower overall survival rate in patients receiving medical treatment is secondary to complications from chemotherapy and radiotherapy. Level of evidence: 2C.

摘要：
研究目的：对巴西圣保罗州口咽鳞状细胞癌（oropharyngeal squamous cell carcinoma）的流行病学资料、临床分期及预后结局进行描述性分析，并评估临床分期与治疗方式对总生存期（overall survival）及无病生存期（disease-free survival）的影响。
研究方法：本研究回顾性分析了圣保罗癌症中心基金会（São Paulo Cancer Center Foundation）数据库中2004年至2014年于圣保罗州确诊的口咽鳞状细胞癌患者的流行病学资料。采用单变量及多变量Cox回归（Cox regression）分析评估与预后结局相关的影响因素，分析过程采用向前逐步筛选法。通过Kaplan-Meier法（Kaplan-Meier method）绘制生存曲线，并采用Gehan-Breslow-Wilcoxon检验（Gehan-Breslow-Wilcoxon test）进行组间比较。
研究结果：本研究共纳入8075例口咽鳞状细胞癌患者。其中86.3%的患者确诊时处于晚期阶段，13.7%处于早期阶段；仅27.2%的患者接受手术治疗，57.5%接受内科治疗。无论在早期还是晚期口咽鳞状细胞癌患者中，接受手术治疗的患者总生存期均长于接受内科治疗的患者。但手术治疗与内科治疗患者的无病生存期无显著差异。
研究结论：内科治疗与手术治疗患者的无病生存期无显著差异，提示两种治疗方案的完全缓解率相近。接受内科治疗的患者总生存期更短，这可能与化疗及放疗所致并发症相关，但基于圣保罗癌症中心基金会提供的数据，本研究无法证实这一关联。未来需开展前瞻性研究，以明确接受内科治疗的患者总生存期较低是否继发于化疗与放疗的并发症。
证据等级：2C。