Efficacy of high-resolution MRI in the prediction of tumor complete response after neoadjuvant chemora-diation therapy for T3 rectal cancer

Abstract

Objective To explore the efficacy of high-resolution MRI in the prediction of tumor complete response after neoadjuvant chemoradiation therapy for T3 rectal cancer. Methods The clinical data of 108 patients with T3 rectal cancer who were admitted to Shanghai Cancer Center of Fudan University from 2010 to 2012 were retrospectively analyzed. The TNM stage of tumor, extramural depth of tumor invasion (mrT3 stage) , involvement of mesorectum and rectal fascia, tumor diameter and distance from anal edge to lower edge of tumor were the main items of evaluation using the high-resolution MRI. A total of 108 patients underwent surgical resection of tumor after neoadjuvant chemoradiation therapy. The tumor complete response after neoadjuvant chemoradiation therapy was evaluated by tumor node metastasis (TNM) stage and tumor regression grade (TRG) . The categorical data and multivariate analysis were done by the single factor analysis of variance (ANOVA) and Logistic regression analysis. Results The positive response rate of the T3a, T3b and T3c in the patients were 61. 5% (16/26) , 36. 9% (24/65) and 11.8% (2/17) after neoadjuvant chemoradiation therapy, respectively. The mrT3, mrN and tumor diameter were the potential factors affecting response of neoadjuvant chemoradiation therapy by the univariate analysis of pathological restaging (χ2 =50. 474, 30. 985 , 8. 318 , P 0.05) . Conclusion The mrT3 in patients undergoing high-resolution MRI before neoadjuvant chemoradiation therapy could predict the tumor complete response after neoadjuvant chemoradiation therapy for T3 rectal cancer. Key words: Rectal neoplasms, T3 staging; Neoadjuvant chemoradiation therapy; Magnetic resonance imaging; Prediction