标准淋巴结清扫及规范化取材对胰头癌淋巴结分期的影响

The effect of standardized lymphectomy and sampling of resected lymph nodes on TNM staging of resectable pancreatic head cancer

目的探讨标准化淋巴结清扫及标本规范化取材对判断胰头癌淋巴结转移及TNM淋巴结分期的影响。方法将北京医院普通外科2017年12月至2018年11月因胰头导管腺癌行标准胰十二指肠切除术的患者作为研究组,按照《胰腺癌诊治指南(2014)》行标准范围的根治性手术,由术者根据日本《胃癌处理规约》对新鲜切除标本行淋巴结分组取材,该组纳入33例,年龄(59.8±15.2)岁。同时收集2015年12月至2016年11月因胰头癌行标准胰十二指肠切除患者的病理学报告,并由病理科基于固定标本取材,共纳入29例作为对照组,年龄(57.0±13.0)岁。比较两组淋巴结清扫数量、清扫达标率及转移阳性率;结合AJCC第7版和第8版,分析规范化取材对淋巴结分期的影响。符合正态分布的计量资料应用独立样本t检验,不符合正态分布的计量资料应用秩和检验;计数资料应用χ^2检验进行统计分析。结果研究组和对照组患者的基线资料具有可比性(P值均>0.05)。研究组和对照组淋巴结清扫数量的差异有统计学意义[(23.3±8.9)枚比(12.9±5.9)枚,t=0.653,P=0.000]。研究组与对照组淋巴结清扫数量≥15枚的比例的差异有统计学意义[81.8%(27/33)比34.5%(10/29),χ^2=14.373,P=0.000]。研究组第17a+17b、14a+14b、8a+8p组淋巴结转移率分别为36.4%(12/33)、30.3%(10/33)及9.1%(3/33),第14组和第8组淋巴结转移率的差异有统计学意义(χ^2=4.694,P=0.030)。由于第8版N分期的调整,研究组有2例(6.1%,2/33)从ⅠB期升为ⅡA期,同时有7例(21.2%,7/33)从ⅡA期降为ⅠB期;有5例(15.2%,5/33)从ⅡB期升为Ⅲ期,占所有ⅡB分期的25.0%(5/20)。结论由于解剖特点和转移率高,第14组淋巴结应作为第1站淋巴结常规清扫。标准化淋巴结清扫后由术者对新鲜标本进行的规范化取材,可显著增加淋巴结检出量,有助于进行准确的临床分期。

Objective To examine the effect of standardized lymphectomy and sampling of resected lymph nodes (LN) on TNM staging of resectable pancreatic head cancer. Methods Consecutive patients with resectable pancreatic head cancer who received standard pancreatoduodenctomy at Department of General Surgery in Beijing Hospital from December 2017 to November 2018 were recruited as study group. After operation, the surgeon sampled lymph nodes from the fresh specimen following the Japanese Gastric Cancer Guidelines.Thirty-three cases were recruited in the study group and the mean age was (59.8±15.2) years.Pathologic reports from December 2015 to November 2016 were taken as control group, containing 29 cases with age of (57.0±13.0) years. Number of lymph nodes, standard-reaching ratio and positive nodes ratio were compared between two groups. According to the seventh edition and eighth edition of TNM staging, the changes of N staging and TNM staging were analysed. The quantitative data conforming to normal distribution were tested by independent sample t test, the quantitative data not conforming to normal distribution were tested by rank sum test, and the enumeration data were analysed by χ^2 test. Results The basal data of the two groups were comparable (all P>0.05). The number of lymph nodes sampled in the study group was 23.27±8.87, significantly more than in control group (12.86±5.90, t=0.653, P=0.000).Ratio of cases with more than 15 nodes was 81.8%(27/33) in the study group and 34.5%(10/29) in the control group with statistical significance (χ^2=14.373, P=0.000). In the study group, the positive lymph node ratios of No. 17a+17b, 14a+14b, 8a+8p LN were 36.4%(12/33), 30.3%(10/33) and 9.1%(3/33) respectively. The positive lymph node ratio in No.14a+14b LN was higher than in No.8 LN (χ^2=4.694, P=0.030). According to the change in N staging system in the AJCC eighth edition, 2 cases (6.1%, 2/33) changed from ⅠB to ⅡA, 7 cases (21.2%, 7/33) from ⅡA to ⅠB and 5 cases (15.2%, 5/33) changed from ⅡB to Ⅲ(25.0%, 5/20). Conclusions No.14 LN should be treated as the first station rather than second station because of the anatomic character and higher metastatic ratio. Standardised lymphectomy and sampling may increase the number of LN resected and improve the TNM staging of resectable pancreatic head cancer.