低位直肠癌新辅助治疗后淋巴结检出数目与预后的关系研究

Correlation between the number of retrieved lymph nodes and prognosis in low rectal cancer after neoadjuvant chemoradiotherapy

目的探讨低位直肠癌患者新辅助放化疗后淋巴结检出数目(LNs)与患者预后的关系。方法纳入海南医学院第二附属医院2014年1月至2016年12月350例接受新辅助放化疗联合手术治疗的低位直肠癌患者为研究对象。分析影响患者预后的临床病理因素;通过受试者工作特征(ROC)曲线探讨评估新辅助放化疗后患者3年生存率的最佳淋巴结检出数目,将患者按照最佳淋巴结检出数目分为两组,采用Kaplan-Meier法和Log-rank检验分析3年生存情况;将患者依据直肠癌消退分级(RCRG)分组(Ⅰ级,或Ⅱ~Ⅲ级),分析患者3年生存情况。结果 350例患者共检出淋巴结数目3 987枚,平均每例检出(11.4±4.7)枚。淋巴结检出数目、肿瘤大小、肿瘤分化程度、TNM分期、术后T分期、术后N分期及RCRG与患者3年生存率有关(均P<0.05),年龄及性别与患者3年生存率无关(均P>0.05)。淋巴结检出数目、TNM分期、术后N分期及肿瘤消退分级是3年生存率的独立影响因素(均P<0.05),肿瘤大小、肿瘤分化程度及术后T分期并非3年生存率的独立影响因素(均P>0.05)。ROC曲线提示3年生存时间相关的淋巴结检出数目的最佳临界值为10枚,敏感度为84.3%,特异度为81.7%。LNs≤10枚组3年累积生存率高于LNs>10枚组(P<0.05)。RCRGⅠ级患者中,LNs≤10枚组3年累积生存率高于LNs>10枚组,差异有统计学意义(P<0.05);RCRGⅡ~Ⅲ级患者中,LNs≤10枚组和LNs>10枚组3年累积生存率比较差异无统计学意义(P>0.05)。结论淋巴结检出数目是新辅助放化疗联合手术治疗后低位直肠癌患者预后的独立影响因素,且淋巴结检出数目在10枚以下的患者3年累积生存率更高,而肿瘤消退反应为RCRGⅠ级时,可观察到同样的结果。

Objectives To investigate the correlation between the number of retrieved lymph nodes(LNs)and prognosis in pa⁃tients with low rectal cancer after neoadjuvant chemoradiotherapy.Methods The study included 350 patients with low rectal can⁃cer who received neoadjuvant chemoradiotherapy and surgery at the Second Affiliated Hospital of Hainan Medical University from January 2014 to December 2016.We analyzed the clinicopathological characteristics and their prognostic value.Receiver Operat⁃ing Characteristic(ROC)curve was used to determine the optimal LNs concerning patients’three-year survival.The patients were divided into two groups by using this cut-off.The Kaplan-Meier method and Log-rank tests were used to compare the three-year survival between these two groups.Patients were also grouped according to Rectal Cancer Regression Grade(RCRG)(RCRGⅠvs.RCRGⅡ~Ⅲ),and the three-year survival was compared between these two groups.Results A total of 3,987 lymph nodes,with a mean(SD)of 11.4(4.7)in each case,was retrieved.Three-year survival was significantly associated with the number of retrieved LNs,tumor size,differentiation,TNM stage,postoperative T stage,postoperative N stage,and RCRG(P<0.05),while age and gender did not affect the three-year survival(P>0.05).The independent factors influencing three-year surviv⁃al were the number of retrieved LNs,TNM stage,postoperative N stage,and RCRG(P<0.05).Tumor size,differentiation,and postoperative T stage were not independent factors influencing three-year survival(P>0.05).ROC showed that the optimal LNs was 10 concerning three-year survival,with a sensitivity of 84.3%and a specificity of 81.7%.Patients with LNs≤10 had signifi⁃cantly better three-year survival than those with LNs>10(P<0.05).In patients with RCRGⅠ,three-year survival was significant⁃ly better in patients with LNs≤10 than those with LNs>10.This difference was absent in patients with RCRGⅡ~Ⅲ(P>0.05).Conclusion The number of retrieved LNs was an independent prognostic factor in patients with low rectal cancer who received neoadjuvant chemoradiotherapy and surgery.Patients with LNs≤10 had significantly better three-year survival.These similar results were noticeable in patients with RCRGⅠas well.