Advances Of Prognostic Factors Of Neoadjuvant Chemoradiotherapy Sensitivity In Locally Advanced Rectal Cancer

Rectal cancer(T1/2,or N0)in the early stage can be cured by TME surgery,with a 5-year survival rate of 90% or more.As for the locally advanced rectal cancer(T3/4,or N+),it is the first choice at home and abroad to conduct the preoperative concurrent chemoradiation plus TME surgery plus postoperative adjuvant treatment due to the high rate of local recurrence of direct TME surgery,failure to retain the anus,failure to do radical resection(R0),etc.The preoperative concurrent chemoradiotherapy has many advantages for locally advanced rectal cancer,such as reducing tumor volume,reducing local tumor staging,increasing the possibility of R0 resection,reducing radiation toxicity,increasing the rate of anal preserving,reducing local recurrence rate,and so on.However,we can often see in clinical practice that there are significant differences among different individuals in the efficacy of standard neoadjuvant treatment.In some treatment-sensitive individuals,the tumor can even completely subside,reaching complete clinical remission and even complete pathological remission.In some patients who are insensitive to treatment,tumor progression occurs during preoperative radiotherapy chemotherapy.For this group of patients,preoperative radiotherapy and chemotherapy make the patient miss the best opportunity of surgery.Benefits for some patients will be largely get if patients who are potentially beneficial to neoadjuvant chemoradiation can be selected in locally advanced rectal cancer patients.The sensitivity of the local advanced rectal cancer to preoperative radiotherapy and chemotherapy is affected by many factors,such as pretreatment CEA levels,EGFR levels,microsatellite status and immune microenvironment in tumor tissues.This article reviews the related factors of preoperative radiotherapy and chemosensitivity prediction in recent literature,as well as the existing problems and research progress.