The Effect And Clinical Significance Analysis Of Local Advanced Rectal Cancer To Neoadjuvant Chemoradiotherapy Combined With Laparoscopic TME Surgery

Background:Neoadjuvant chemoradiotherapy combined with radical TME surgery has been the standard regimen for patients with locally advanced mid and low rectal cancer.Neoadjuvant chemoradiotherapy can reduce the tumor stage,decline the regional lymph nodes and reduce the recurrence rate.It has been an important topic to evaluate the long-term prognosis of these patients and it is reported that the effect of preoperative chemoradiotherapy in mucinous adenocarcinoma is not so favorable as non-mucinous adenocarcinoma.The present study was to represent the effect of clinical and pathological factors to the long-term prognosis of the patients with advanced mid and low rectal cancer after neoadjuvant chemoradiotherapy and laparoscopic radical surgery.Methods:Clinical and pathologic data were recorded and analyzed of 324 patients with advanced mid and low rectal cancer after neoadjuvant chemoradiotherapy from June 2010 to July 2016.The tumor and lymph node downstaging of the two groups were analyzed.Disease-free survival(DFS)were also assessed.The relationship between clinicopathologic factors and disease free survival(DFS)was analyzed.Results:Mucinous adenocarcinoma was present in 28 patients(MA group)and non-mucinous adenocarcinoma in 296(NMA group).There were more patients under the age of 50 years in the MA group(50%),compared with NMA group(26.4%)(p=0.014).The MA group had significantly lager tumor diameter and more positive lymph nodes compared with NMA group(p<0.001).The MA group had significantly poorer T-stage(p=0.035)and N-stage than the NMA group(p<0.001),and the N-downstaging was significantly less frequent in the MA group than in the NMA group(32.1%vs 62.5%,p=0.002).The estimated 3-year DFS was 67.7%and 79.6%(p=0.575).3-year expected DFS in patients with positive lymph nodes were 75.4%,which was significantly lower than those with negative node(88.8%,p<0.001).Patients with tumor less than 3cm,Pathological complete remission,downstaging of lymph nodes,lower pathological TNM stage,lower tumor regression grade(TRG)or without local invasive factors such as vascular tumor embolus,perineural invasion and cancer nodules had a better DFS.Cox regression analyze showed that the postoperative lymph nodes status,mean tumor diameter,TRG and local invasive factor were independent risk factors to DFS.In the subgroup analyze of 112 patients with positive lymph nodes,the ratio of positive lymph nodes and TRG were independent risk factors of DFS.Conclusions:Our study showed preoperative chemoradiotherapy had limited effect in patients with rectal mucinous adenocarcinoma compared with those with rectal non-mucinous adenocarcinoma,especially in those with lymph node metastasis.But the limited effect was not associated with worse long-term prognosis in our study,so perspective randomized controlled trials are expected to confirm our results.Pathologic positive lymph nodes,TRG,lager size of tumor and contained invasive factors such as vascular tumor embolus,perineural invasion and cancer nodules were associated with worse long-term oncologic prognosis for patients with locally advanced mid and low rectal cancer after neoadjuvant chemoradiotherapy.When estimating the long-term oncologic prognosis of patients with positive lymph nodes,the positive rate of lymph nodes may be a better predictive index than postoperative lymph nodes status.