Clinical Predictors Of Short Term Efficacy After Neoadjuvant Chemoradiotherapy In Locally Advanced Rectal Cancer

Research background and purposeIn the past two decades,the incidence of colorectal cancer(CRC)has been increasing in China due to economic development,westernized diet and lifestyle,lack of exercise and other risk factors.Rectal cancer is the most common.The incidence of rectal cancer accounts for one-half of the incidence of colorectal cancer,and most patients in the local advanced stage at the time of consultation.Total mesorectal excision(TME)after neoadjuvant chemoradiotherapy(nCRT)has been widely used in locally advanced rectal cancer.About 13%-27%of patients achieve pathological complete response(pCR)after neoadjuvant chemoradiotherapy,and about 50%of patients achieve tumor downstaging(ypT0-2N0M0).Good pathological response is related to increasing the rate of surgical resection,increasing the rate of anus preservation,increasing disease-free survival,reducing the rate of local recurrence and distant metastases.However,due to individual differences,some patients may not be sensitive to chemoradiotherapy and therefore delay the time of surgery.Therefore,this study retrospectively analyzes clinical factors and explores the factors related to the short term efficacy of neoadjuvant chemoradiotherapy for locally advanced rectal cancer in order to guide the selection of individualized treatment options for patients.Materials and MethodsRetrospective analysis of clinical data of 65 patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy at Zhujiang Hospital from April 2011 to May 2019.All patients underwent neoadjuvant radiotherapy and concurrent chemotherapy based on fluorouracil.The efficacy of neoadjuvant chemoradiotherapy before surgery was evaluated by tumor downstaging and pathological complete response.SPSS20.0 statistical software was used for statistical analysis,and univariate analysis and Logistic regression model were used to analyze clinical predictive factors related to efficacy.ResultsAll patients had completed treatment,of which 13 patients(20%)achieved pathological complete response and 33 patients(50.8%)achieved tumor downstaging.Univariate analysis showed that pretreatment serum CEA level(P=0.028)and clinical T stage(P=0.044)were significantly associated with tumor downstaging after neoadjuvant chemoradiotherapy in rectal cancer and pretreatment serum CEA level(P=0.011)and pretreatment serum CA199 level(P=0.004)were significantly correlated with tumor pathological complete response level after neoadjuvant chemoradiotherapy in rectal cancer.Multivariate analysis showed that the level of CEA(P=0.038)before treatment was the independent factor of downstaging.CEA level(P=0.035)and CA199 level(P=0.015)before treatment were independent factors of pCR after neoadjuvant chemoradiotherapy in rectal cancer.Conclusion1.For patient with locally advanced rectal cancer,tumor downstaging and pathological complete response could be achieved after neoadjuvant chemoradiotherapy.2.Pretreatment CEA level,pretreatment CA199 level,and clinical T staging were factors influencing the short term efficacy of neoadjuvant chemoradiotherapy for locally advanced rectal cancer.3.Low level of CEA before treatment maybe was predictor of tumor downstaging after neoadjuvant chemoradiotherapy in locally advanced rectal cancer.4.Low level of CEA and CA199 before treatment maybe were predictor factors of pCR after neoadjuvant chemoradiotherapy in locally advanced rectal cancer rectal cancer.