Prognostic Significance Of The Depth Of Mesorectal Invasion (DMI) On Preoperative High-resolution Magnetic Resonance Imaging In Pathological T3NO Rectal Cancer

Purposes The aim of this study was to evaluate the association between the depth of mesorectal invasion(DMI)on high-resolutionmagnetic resonance imaging(MRI)and the prognosis of patients with pathological T3N0 rectal cancer.Methods sixty-four patients with pathological T3N0 rectal cancer who were treated in Fujian Medical University Union Hospital were investigated using high-resolution MRI.Those patients was assigned into two subgroups by measuring the depth of mesorectal invasion(mr DMI≤5,and DMI>5mm),and according to the circumferential resection margin(mr CRM)divided into mr CRM>1mm group and mr CRM≤1mm group,according to mr CRM combined with mr DMI divided into mr CRM≤1 mm and mr DMI>5mm and comparative group,Compare the prognosis of the two groups.The Kaplan–Meier method and the log-rank test were used for the survival analysis.To investigate independent predictors of the OS,RFS in clinical T3 rectal cancer,a Cox multivariate regression model was constructed.Statistical significance was determined to exist at P < 0.05.Results :1.For all the p T3N0 patients,The five-year OS rate was 81.6% overall,The 5-year RFS rate was 76.5%.2.A survival analysis showed that patients with mr CRM≥1mm patients had a significantly poorer prognosis in the RFS(74.4% vs.89.7%,P<0.05)and OS(62.1%vs.87.6%,p<0.05).3.Patients with mr DMI>5mm revealed a significantly poorer prognosis than those with mr DMI ≤5 mm in the RFS(P=0.012).4.The OS and RFS of the patients in mr CRM≤1 mm and mr DMI>5mm were significantly worse than for patients in comparative groupgroup(62.3% vs.89.9%,P<0.05;43.5% vs.88.7%,P<0.05).5.the univariate and multivariate analysis indicated that CRM is an independent impact factor in the RFS and OS(P=0.005,P =0.001).Conclusion:The mr DMI,as well as the mr CRM,may be an important preoperative prognostic factor for patients with clinical T3 rectal cancer.