Prognostic impact of the neoadjuvant rectal score as compared with the tumor regression grade and yield pathologic TNM stage in patients with locally advanced rectal cancer after neoadjuvant chemoradiotherapy

Background/Aim: The present study compared the prognostic value of the yield pathologic (yp) stage, tumor regression grade (TRG), and neoadjuvant rectal (NAR) score in patients with locally advanced rectal cancer (LARC) who received neoadjuvant chemoradiotherapy (nCRT). Patients and Methods: For the assessment of tumor regression, the Dworak grading system was used. The NAR score was calculated using the following equation: (5ypN-3[cT-ypT]+12)²÷9.61. Results: In univariate analysis, the NAR score and ypTNM stage were significantly associated with DFS [hazard ratio (HR)=2.514, p<0.001 and HR=3.200, p<0.001] and OS (HR=2.292, p=0.001 and HR=2.859, p<0.001), whereas the TRG was significantly associated with only DFS (HR=2.008, p=0.017). In multivariate analysis, the ypTNM stage was the only independent prognostic factor for DFS (HR=3.796, p<0.001) and OS (HR=3.591, p=0.0034). Conclusion: Only the ypTNM stage was significantly associated with survival outcomes in multivariate analysis, suggesting that it is the most powerful prognostic factor of nCRT in patients with LARC.