Can the mesorectal fat tissue volume be used as a predictive factor in foreseeing the response to neoadjuvant chemoradiotherapy in rectum cancer? A CT-based preliminary study.

We performed a retrospective analysis of 88 patients (mean age 62.7 years [range, 33-90 years]; 31 males and 57 females). A positive response to nCRT was present in 47 patients. There were 59 patients with stage 3 disease. 46 patients demonstrated lymph node involvement. The mean MRV was 69.6 ± 31.0 ml in no-response group and 105.8 ± 47.5 ml in response-positive patients (p < 0.05). MRV showed the highest correlation with visceral fat volume (VFV). There was a negative correlation between the MRV and the N stage. A cut-off value of ≥ 69.4 for MRV predicted the repsonse to nCRT, with 82.9% sensitivity and 58.5% specificity [AUC: 0.757 (0.653-0.842), p < 0.001] in receiver operating characteristic (ROC) curve analysis CONCLUSIONS: MRV can be used as a novel parameter in predicting of pathological response to nCRT in locally advanced rectal cancer patients.