Short Term Efficacy Of Total Neoadjuvant Therapy For Locally Advanced Rectal Cancer

Objective:To investigate the short-term efficacy of total neoadjuvant therapy(TNT)for locally advanced rectal cancer.Methods:A total of 81 patients with locally advanced rectal cancer who had completed treatment in the same treatment group of the First Affiliated Hospital of Kunming Medical University from May 2017 to December 2020 were selected and divided into long-course radiotherapy TNT group(n=35),short-course radiotherapy TNT group(n=30),and NAC group(n=16)who refused radiotherapy and had negative MRI evaluation of CRM and EMVI.The long-course TNT group was given 8 cycles of mFOLFOX-6 chemotherapy one week after the end of radiotherapy,the short-course TNT group was given 10 cycles of mFOLFOX-6 chemotherapy one week after the end of radiotherapy,and the NAC group was given 11 cycles of mFOLFOX-6 after the treatment plan was developed.All the three groups received surgical treatment two weeks after the end of chemotherapy.Collect baseline data,treatment data,surgical data,postoperative pathological data,and toxic data of all patients,and compare and analyze the treatment efficacy,perioperative safety and the acute toxicity etween the two TNT groups and between the two TNT groups and the NAC group.Results:The operation time(P=0.007),intraoperative blood loss(P=0.006),T down-staging rate(85.7%,73.3%,37.5%,P=0.002),N down-staging rate(91.4%,86.7%,62.5%,P=0.029)and the rate of preventive ileostomy(84.8%,80.0%,43.8%,P=0.006)were statistically significant in the long-course radiotherapy TNT group,short-course radiotherapy TNT group,and NAC group.The tumor complete response rate(cCR+pCR)was 25.7%,20.0%,and 6.3%,respectively(P=0.269).In the long-course radiotherapy TNT group,2(5.7%)patients refused surgery due to clinical evaluation of cCR,and chose the wait-and-watch strategy.More than 82.9%of the patients completed all neoadjuvant chemotherapy.The toxicity above grade 3 was 42.9%,33.3%and 31.3%,respectively(P=0.633).The most common toxicity was neutropenia(11 cases)and gastrointestinal reaction(13 cases).Compared with the TNT group,the NAC group had shorter operation time,less intraoperative blood loss and lower the rate of preventive ileostomy,but the rate of tumor regression was also lower(P<0.025).There was no significant difference between the long-course radiotherapy TNT group and the short-course radiotherapy TNT group in short-term treatment efficacy,perioperative safety,and acute toxicity of radiotherapy and chemotherapy(P>0.05).Conclusions:1.TNT with radiotherapy can increase the tumor complete response rate of locally advanced rectal cancer,allowing more patients to choose a waiting-and-watch strategy to preserve anal function;2.Compared with the long-course radiotherapy TNT mode,the short-course radiotherapy TNT mode does not increase the surgical difficulty and postoperative complications,the tumor response is equivalent,and the toxicity is relatively low;3.Compared with TNT with radiotherapy,NAC alone can effectively reduce the operation time,blood loss and the rate of preventive ileostomy.4.The new adjuvant treatment which advanced postoperative chemotherapy to preoperative can improve the compliance of patients.