Comparison of MRI and pathology results in evaluation of T and N stage of rectal cancer

Aim. To compare MRI evaluated rectal cancer cTN stage and pathologically proven pTN stage after rectal cancer surgery. Objectives. To evaluate MRI diagnostic accuracy, sensitivity and specificity for assessment of T stage and N stage of rectal cancer. To evaluate efficiency of neoadjuvant therapy. Methods. A retrospectral investigation were made with clinical data of HLUHS Surgery clinic’s 135 patients, who were treated there in the period of 2013.01-2016.09 for rectal cancer. Statistical analysis were performed using SPSS 21.0 software. Agreement between stages was calculated using linear weighted Kappa statistics. Study participants. HLUHS Surgery clinic’s 135 patients, who were treated there in the period of 2013.01-2016.09 for rectal cancer with MRI evaluated T and N rectal cancer stages. Results. Pathology evaluation found 10.37% - pT1, 22.96% - pT2, 57.78% - pT3 and 8.88% - pT4 stage rectal cancer. pN0 stage were found in 59.83% patients, pN1 - 27.87%, and pN2 in 12.30%. MRI found 8.15% cases of T1 stage rectal cancer, 11.85% - T2, 71.85% - T3 and 8.15% of T4 rectal cancer. MRI accuracy in evaluating T stage was 73,33%. There was good stage agreement between MRI and histology results K=0,611 (95% PI 0,49– 0,73). MRI accuracy evaluating N stage was 40,98%. Conclusions. MRI is accurate diagnostic method in determining preoperative T stage and not accurate enough in evaluating N stage of rectal cancer. Recommendations. It is better to use MRT and EUS to evaluate tumors T stage. MRI is better for evaluating T stage of large, CRM possitive tumors