To evaluate the predictive value of MRI features and pathological parameters on local recurrence, metastasis and progression free survival (PFS) for locally advanced rectal cancer after neoadjuvant chemoradiotherapy and subsequent total mesorectal excision surgery.

A retrospective analysis of 95 patients with locally advanced rectal adenocarcinoma who underwent total mesorectal excision after neoadjuvant chemoradiotherapy was performed. Univariate and multivariate analyses were performed to evaluate the predictive value of MRI features before chemoradiation and postoperative pathological parameters on progression free survival.

Among the 95 cases, 5 cases occured local recurrence, 21 cases developed, 3 cases including both locally recurrence and distant metastasis, 19 died and 47 had no recurrence or metastasis at the last of follow-up. Univariant analysis showed that MRI signs before chemoradiation, namely, mr circumferential resection margin, mr levator ani muscle invasion, mr lymphatic vessel invasion, mr tumor deposition and postoperative pathological parameters, yp circumferential resection margin, yp lymphatic vessel invasion were related to PFS (P<0.05). Multivariate analysis of Cox proportional hazard model showed that mr lymphatic vessel invasion and mr tumor deposition were independent factors for PFS (OR=2.774 and 3.029, P<0.05).

Lymphatic vessel invasion and tumor deposition on MRI are independent prognostic factors for progression free survival of locally advanced rectal cancer after neoadjuvant chemoradiotherapy and TME surgery. To some extent, MRI signs can assess local recurrence and distant metastasis in locally advanced rectal cancer patients after neoadjuvant chemoradiotherapy and mesorectal excision.

Rectal neoplasms; Adenocarcinoma; Chemoradiotherapy, neoadjuvant; Magnetic resonance imaging; Progression-free survival