Impact of neoadjuvant therapy on the number of harvested lymph nodes in D2 radical resection of the proximal locally advanced gastric cancer / 中华消化外科杂志

ABSTRACT

Objective To explore the impact of neoadjuvant therapy on the number of harvested lymph nodes in D2 radical resection of the proximal locally advanced gastric cancer (GC).Methods The retrospective cohort study was conducted.The clinicopathological data of 319 patients with proximal locally advanced GC who were admitted to the Beijing Cancer Hospital from January 2013 to September 2016 were collected.Of 319 patients,200 underwent D2 radical resection of GC and didn't undergo neoadjuvant therapy who were divided into the surgery group,88 underwent neoadjuvant chemotherapy into the chemotherapy group,and 31 underwent neoadjuvant chemoradiotherapy into the chemoradiotherapy group.Observation indicators and evaluation criteriacomparison of postoperative pathological results among 3 groups,according to tumor staging guideline of American Joint Committee on Cancer (AJCC) (8th version) Measurement data with normal distribution were represented as x±s,comparisons among groups were analyzed using the ANOVA.Measurement data with skewed distribution were described as M (range),comparisons among groups were analyzed using the ANOVA,and pairwise comparisons were analyzed using nonparametric test.Comparisons of count data among groups were analyzed using the exact chisquare test,and pairwise comparisons were analyzed using the chi-square partition method.Results Comparison of postoperative pathological results among 3 groupsstage T0,Tla,Tlb,T2,T3,T4a and T4b of T staging were respectively detected in 0,2,10,24,99,58,7 patients in the surgery group and 5,1,2,11,41,26,2 patients in the chemotherapy group and 5,1,2,8,10,4,1 patients in the chemoradiotherapy group.Stage N0,N1,N2,N3a and N3b of N staging 56,41,34,47,22 patients in the surgery group and 29,17,27,10,5 patients in the chemotherapy group and 18,10,2,1,0 in the chemoradiotherapy group.Cases with and without lymphovascular invasion were respectively 124,76 in the surgery group and 43,45 in the chemotherapy group and 6,25 in the chemoradiotherapy group.Total number of harvested lymph nodes,number of lymph node metastases and rate of lymph node metastasis in the surgery,chemotherapy and chemoradiotherapy groups were respectively 31 (range,15-87),30 (range,15-62),21 (range,15-36) and 3 (range,0-39),2 (range,0-37),0 (range,0-7) and 9.2％ (range,0-91.3％),7.7％ (range,0-78.7％),0 (range,0-30.4％).There were statistically significant differences in the T staging,N staging,with and without lymphovascular invasion,total number of harvested lymph nodes,number of lymph node metastases and rate of lymph node metastasis among groups (x2 =35.799,32.489,21.076,Z =27.120,22.088,16.947,P ＜ 0.05).There were statistically significant differences in the above indicators between surgery group and chemoradiotherapy group (x2 =28.500,20.124,19.570,P＜0.05),and no statistically significant difference in the above indicators between surgery group and chemotherapy group (x2 =11.436,12.343,4.295,P＞ 0.05).There were statistically significant differences in the N staging,with and without lymphovascular invasion,total number of harvested lymph nodes,number of lymph node metastases and rate of lymph node metastasis between chemotherapy group and chemoradiotherapy group (x2 =14.027,8.313,P＜ 0.05),and no statistically significant difference in the T staging between chemotherapy group and chemoradiotherapy group (x2=11.742,P＞ 0.05).Conclusion Neoadjuvant chemoradiotherapy could reduce the total number of harvested lymph nodes and number of lymph node metastases after radical resection of proximal locally advanced GC.