The effect of standardized lymphectomy and sampling of resected lymph nodes on TNM staging of resectable pancreatic head cancer / 中华外科杂志

ABSTRACT

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 χ2 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 (χ2=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 (χ2=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.