老年与非老年直肠黏液腺癌患者对不同放疗策略的受益可能不同：一项基于SEER数据库的回顾性研究

目的探讨老年与非老年直肠黏液腺癌患者对于新辅助放疗、辅助放疗的受益情况，并分析影响直肠黏液腺癌患者预后的因素。 方法应用美国国家癌症研究所的监测、流行病学和结果数据库（SEER），收集2000~2016年，病理诊断为直肠黏液腺癌的患者共3 997例，根据年龄分为老年组（≥60岁）和非老年组（<60岁），分析比较两组接受新辅助放疗联合手术、单纯手术和术后辅助放疗患者的预后情况，对两组患者的三种治疗方式分别进行倾向得分匹配，比较不同治疗方法对预后的影响，应用Kaplan-Meier法分别绘制生存曲线，应用Log-rank检验分析各组生存差异，应用COX比例风险模型分析影响直肠黏液腺癌患者预后的因素。 结果三种治疗方案的总生存率，新辅助放疗总生存率最高，其次为术后放疗，最后为单纯手术组，组间比较差异有统计学意义（χ²=13.117，22.541；P<0.05）。但三种治疗方案的肿瘤特异性生存，仅新辅助放疗显著高于术后放疗（χ²=4.023，P=0.045）。对各种治疗方案进行倾向得分匹配后，老年患者新辅助放疗的总体生存率显著高于单纯手术（χ²=4.874，P=0.027），非老年患者单纯手术的总体生存率（χ²=5.530，P=0.019）和肿瘤特异性生存率（χ²=4.825，P=0.028）均显著高于术后放疗。高龄（≥60岁）、男性、未化疗和高TNM分期是直肠黏液腺癌患者总生存率较差的影响因素，其HR分别为1.689（95% CI=1.524~1.871）、1.110（95% CI=1.007~1.223）和1.549（95% CI=1.338~1.792），Ⅱ期HR=2.675（95% CI=1.191~6.008），Ⅲ期HR=3.617（95% CI=1.612~8.115），Ⅳ期HR=10.835（95% CI=4.797~24.474）；高龄（≥60岁）、未化疗和高TNM分期是直肠黏液腺癌患者肿瘤特异性生存率较差的影响因素，其HR分别为1.297（95% CI=1.156~1.456），1.344（95% CI=1.129~1.601），Ⅲ期HR=6.365（95% CI=1.582~25.614），Ⅳ期HR=20.957（95% CI=5.189~84.637）。 结论老年直肠黏液腺癌患者可能从新辅助放疗中获益，而对于非老年患者，放疗的预后并不优于单纯手术治疗。

Elderly and non-elderly patients with rectal mucinous adenocarcinoma may benefit from different radiotherapy strategies differently: a retrospective study based on SEER database

ObjectiveTo investigate the benefit of neoadjuvant radiotherapy and adjuvant radiotherapy in elderly and non-elderly patients with rectal mucinous adenocarcinoma, and to analyze the factors influencing the prognosis of patients with rectal mucinous adenocarcinoma. MethodsBased on the Surveillance, Epidemiology, and End Result s database (SEER) of the National Cancer Institute of the United States, 3 997 patients with rectal mucinous adenocarcinoma diagnosed pathologically from 2000 to 2016 were collected. According to the patient′s age, the patients were divided into the elderly group (≥ 60 years old) and the non-elderly group (< 60 years old). The prognosis of the two groups was analyzed and compared. Three treatment methods of the two groups were matched by the propensity score matching method, and the influence of different treatment methods on the prognosis was compared. Kaplan-Meier method was used to draw the survival curve, Log rank test was used to analyze the survival difference of each group, and Cox proportional risk model was used to analyze the factors affecting the prognosis of patients with rectal mucinous adenocarcinoma. ResultsThe overall survival (OS) rate of neoadjuvant radiotherapy was the highest, followed by postoperative radiotherapy, and finally by operation only, there were significant differences between each two groups (χ²=13.117, 22.541; P<0.05). However, the cancer-specific survival rate of the neoadjuvant chemoradiotherapy was significantly higher than that of postoperative radiotherapy (χ²=4.023, P=0.045). After propensity score matching for all data, the overall survival rate of neoadjuvant chemoradiotherapy was significantly higher than that of surgery only (χ²=4.874, P=0.027). The OS (χ²=5.530, P=0.019) and CSS (χ²=4.825, P=0.028) of non-elderly patients after surgery alone were significantly higher than those of postoperative radiotherapy. Elder (≥60 y), male, unchemotherapy, and high TNM stage are the influencing factors of poor OS of patients with rectal mucinous adenocarcinoma. Their HRs are 1.689 (95% CI=1.524~1.871), 1.110 (95% CI=1.007~1.223), 1.549 (95% CI=1.338~1.792), StageⅡ HR=2.675 (95% CI=1.191~6.008), StageⅢ HR=3.617 (95% CI=1.612~8.115), PhaseⅣ HR=10.835(95% CI=4.797~24.474); elder (≥60 y), unchemotherapy, and high TNM stage are the influencing factors of poor CSS in patients with rectal mucinous adenocarcinoma, and their HRs are 1.297 (95% CI=1.156~1.456), 1.344 (95% CI=1.129~1.601), stageⅢ HR=6.365 (95% CI=1.582~25.614), stageⅣ HR=20.957 (95% CI=5.189~84.637). ConclusionElderly patients with rectal mucinous adenocarcinoma may benefit from neoadjuvant radiochemotherapy. For non-elderly patients, the prognosis of radiotherapy is not better than that of surgery alone.