Analysis Of Safety And Oncological Effect About Laparoscopic Surgery Of Local Advanced Rectal Cancer After Neoadjuvant Therapy

Objective:Comparison of the safety and oncologic effect of laparoscopic surgery after neoadjuvant therapy with direct laparoscopic surgery for locally advanced rectal cancer by propensity score matching.Methods:From November 1,2015 to November 30,2021,636 patients who underwent rectal cancer surgery in the First Affiliated Hospital of Gannan Medical University were selected.According to the inclusion criteria and exclusion criteria,505 patients performing laparoscopic rectal cancer surgery who were 50 patients with laparoscopic surgery after neoadjuvant therapy and 455 patients with direct laparoscopic surgery were included.According to propensity score matching method,50 patients selected from the patients undergoing direct laparoscopic surgery matched with the patients who undergoing laparoscopic surgery after neoadjuvant therapy in a 1:1 ratio.The matched 100 patients were divided into experimental group（50 cases of laparoscopic surgery after neoadjuvant therapy）and control group（50 cases of direct laparoscopic surgery）according to whether they received neoadjuvant therapy or not.The basic data,surgical data and pathological data of the enrolled patients were retrospectively collected and followed up by inpatient system,outpatient system or telephone until November 30,2022.SPSS 26.0 statistical software was used to perform propensity score matching,and the differences in surgical safety and oncological effect between the two groups after matching were compared.Results:The datas of 100 patients with 50 cases in the experimental group and 50 cases in the control group were statistical analysed after propensity score matching.There were 72 males and 28 females,with an average age of 60.9 years and an average body mass index of 21.58 kg/m².The average distance from tumor to anal verge was5.86cm.The clinical TNM staging of all patients was stageⅡ～Ⅲ,including 20patients with stageⅡand 80 patients with stageⅢ,86%of laparoscopic surgeries were performed by chief physicians.The operation time（223.0min VS 214.7min,P=0.197）,blood loss（151.1ml VS 129.6ml,P=0.271）,conversion rate（8%VS 0%,P=0.117）,postoperative hospital stay（15.9d VS 15.6d,P=0.813）,time to removal of urinary catheter（6.9d VS 5.7d,P=0.189）,time to first flatus（3.1d VS 3.5d,P=0.157）,time to first food intaking（5.4d VS 5.7d,P=0.539）,postoperative complication rate（20%VS 16%,P=0.603）,and reoperation rate within 30 days after operation（8%VS4%,P=0.678）were no significant difference in two groups.Temporary stoma（66.7%VS 35.1%,P=0.006）and the time from surgery to postoperative adjuvant chemoradiotherapy（43.2d VS 34.8d,P=0.03）were significantly difference between with groups.Moreover,the incidence of side effects in the experimental group was significantly lower than that in the control group（58.0%VS 79.6%,P=0.021）.There were no intraoperative complications and no positive circumferential resection margin in either group.The positive distal resection margin was higher in the experimental group（6%VS 0%,P=0.242）,but not statistically significant.The number of lymph nodes detected（10.16 VS 15.76,P<0.001）and positive lymph nodes（0.78 VS 3.98,P<0.001）were less in experimental group,meanwhile,pathological T stage（<T₂/T₃/T₄:26%/26%/8%VS 2%/20%/78%,P<0.001）,and N staging（N₀/N₁/N₂:80%/12%/8%VS 16%/44%/20%,P<0.001）were lower.Median follow-up of 33 months,the experimental group had a lower 3 years local recurrence rate（4%VS 18%,P=0.025）,a higher 3 years disease-free survival rate（74.6%VS57.3%,P=0.042）.3 years distant metastasis rate（16%VS 26%,P=0.220）and overall survival（89.1%VS 85.9%,P=0.616）were similar between the two groups.Conclusion:Neoadjuvant therapy can bring significant tumor downstaging and reduce the side effects of chemoradiotherapy for locally advanced rectal cancer,at the same times,it does not increase the risk of laparoscopic surgery.Compared with direct laparoscopic surgery,laparoscopic surgery after neoadjuvant therapy can significantly reduce local recurrence and prolong disease-free survival,and there is no difference in distant metastasis and overall survival,which has good oncological effect.