Survival analysis of patients with subglottic squamous cell carcinoma based on the SEER database

Abstract Objective: This study aimed to investigate the demographic and clinicopathological characteristics, and survival outcomes of subglottic Squamous Cell Carcinoma (SCC) based on the Surveillance, Epidemiology, and End Results (SEER) database. Methods: Demographic and clinicopathological information, including age, sex, race, tumor size, histologic grade, clinical/TNM stage, tumor invasion extent, Lymph Node Metastasis (LNM) extent, size of metastatic lymph nodes, LNM ratio and treatment data, of 842 subglottic SCC patients diagnosed between 1996 and 2016 were acquired. Kaplan-Meier survival analyses were performed to assess the effects of clinicopathological characteristics, treatment modalities, surgical procedures, and adjuvant therapies on overall survival and cancer-specific survival. Results: Subglottic SCC was more frequent among males aged 60-70 years, with low-grade but locally advanced lesions without local or distant metastases. Age and several primary tumor/LNM related variables were independent risk factors for overall survival and cancer specific survival. Advanced-stage and high-grade disease led to unfavorable prognosis. The most common treatment modality and surgical procedure were surgery plus radiotherapy and total laryngectomy, respectively. Surgery plus radiotherapy provided favorable 5-year survival outcomes, while total laryngectomy had the worst. Surgery plus adjuvant therapy showed better survival outcomes than surgery alone. Conclusion: This study confirmed the rarity of subglottic SCC. Patients with subglottic SCCs suffered poor prognosis especially for those with advanced-stage or high-grade lesions. The prognosis of subglottic SCC remained poor over the years, despite recent progress in cancer therapies. Surgery plus adjuvant therapy improved the survival outcome. Although larynx preservation surgery was beneficial for early-stage disease, total laryngectomy was favored for patients with advanced tumors. Level of evidence: Level 4.

摘要
研究目的：本研究旨在基于监测、流行病学与最终结果（Surveillance, Epidemiology, and End Results, SEER）数据库，探讨声门下鳞状细胞癌（subglottic Squamous Cell Carcinoma, SCC）的人口学特征、临床病理特征及生存结局。
研究方法：收集1996年至2016年间确诊的842例声门下鳞状细胞癌患者的人口学与临床病理信息，包括年龄、性别、种族、肿瘤大小、组织学分级、临床/TNM分期、肿瘤侵袭范围、淋巴结转移（Lymph Node Metastasis, LNM）程度、转移淋巴结大小、淋巴结转移比率及治疗相关数据。采用Kaplan-Meier生存分析，评估临床病理特征、治疗方式、手术术式及辅助治疗对总生存期与癌症特异性生存期的影响。
研究结果：声门下鳞状细胞癌好发于60~70岁男性，多表现为低分级但局部进展期病变，无局部或远处转移。年龄、多项原发肿瘤/淋巴结转移相关变量为总生存期与癌症特异性生存期的独立危险因素。进展期病变及高分级肿瘤提示不良预后。最常用的治疗方式与手术术式分别为手术联合放疗与全喉切除术。手术联合放疗可获得较佳的5年生存结局，而全喉切除术患者的预后最差。手术联合辅助治疗的生存结局优于单纯手术治疗。
研究结论：本研究证实声门下鳞状细胞癌较为罕见。声门下鳞状细胞癌患者总体预后较差，尤其是进展期或高分级病变患者。尽管近年来癌症治疗领域取得一定进展，但多年来声门下鳞状细胞癌的预后仍未得到明显改善。手术联合辅助治疗可改善患者生存结局。虽然喉保留手术对早期病变患者有益，但进展期肿瘤患者更适宜行全喉切除术。
证据等级：4级。