Effect Of Consolidation Chemotherapy On Neoadjuvant Concurrent Chemoradiotherapy For Local Advanced Rectal Cancer

Background:Neoadjuvant chemotherapy is used in the interval between neoadjuvant chemoradiotherapy(NCRT)and surgery,which is a new paradigm in the diagnosis and treatment of local advanced rectal cancer(LARC).In recent years,a number of prospective studies have shown that consolidation chemotherapy,compared with the previous standard treatment mode,can make patients with rectal cancer have better pathological complete response(pCR)and down grading,which are expected to produce clinically significant overall survival(OS)or disease-free survival(DFS)benefits.Objective:This study preliminarily explored and analyzed the efficacy and safety of consolidation chemotherapy in the interval between NCRT and surgery in patients with local advanced rectal cancer,which can provide evidence for the follow-up clinical practice.Methods:A total of 122 patients with locally advanced stage c T3-4 / N+ rectal cancer who received neoadjuvant therapy in Shanxi cancer hospital from October 2014 to January2018 were selected as the research objects,and their clinical data were collected in detail.The patients were divided into control group(n=60)and consolidation group(n=62)according to whether they were treated with neoadjuvant chemotherapy(NAC)at the interval between NCRT and TME.All the above LARC patients and their families signed the relevant informed consent before treatment.The deadline for follow-up was March 29,2021.Results:1.In terms of short-term efficacy,the pCR rate of consolidation chemotherapy group and control group was 24.2% vs 8.3%(P=0.018),the T-down rate was 69.4% vs48.3%(P=0.018),and N-down rate was 69.4% vs 46.7%(P=0.011).2.In terms of long-term efficacy,the 3-year DFS and 3-year OS of the two groups were 80.6% vs 88.3%(P=0.131)and 72.6% vs 78.3%(P=0.791),respectively.3.In terms of side effects,the comparison of severe side effects between consolidation chemotherapy group and control group during neoadjuvant chemotherapy was as follows: leucopenia 8.1% vs 3.3%,thrombocytopenia 1.6% vs 0.0%,anemia 1.6%vs 1.7%,radiation enteritis 4.8% vs 6.7%,radiation dermatitis 1.6% vs 1.7%,nausea and vomiting 4.8% vs 1.7% and radiation cystitis 3.2% vs 1.7%,there was no significant difference in the incidence(P>0.05).Conclusion:the new paradigm of consolidation chemotherapy in NCRT and preoperative interval can improve the pCR rate and phase down rate of LARC patients,and does not increase the side effects of radiotherapy and chemotherapy,perioperative and postoperative complications.