NEOADJUVANT TREATMENT OF LIVER METASTASES OF COLORECTAL CANCER: PREDICTIVE FACTORS OF PATHOLOGICAL RESPONSE

Surgery after neoadjuvant chemotherapy (CT) improves the prognosis of colorectal liver metastases (CRLM).

The aim of this study was to evaluate the predictive factors of the histological response of CRLM after neoadjuvant treatment.

A retrospective monocentric study including patients with CRLM operated after neoadjuvant treatment. Assessment of histological response was based on the Rubbia-Brandt tumor regression grading score. The scores were grouped into two types of response: Response Group (R) and No Response Group (NR).

The study included 77 patients (mean age=56 years, sex ratio=1.57). Node metastases were noticed in 62% of cases. Synchronous liver metastasis was present in 42 cases (55%) and metachronous liver metastasis in 45%. Neoadjuvant treatment consisted of CT only in 52 patients (68%) and CT with targeted therapy in 25 patients (32%). Chemo-induced lesions were present in 44 patients (57%). Histological response was presented (Group R) in 36 cases (47%) and absent (Group NR) in 41 cases (53%). The overall survival of our patients was 32 months. For Group R, survival was significantly greater (p=0.001). The predictive factors of histological response identified were delay in the onset of liver metastasis greater than 14 months (p=0.027) and neoadjuvant treatment combining CT and targeted therapy (p=0.031). In multivariate analysis, the type of neoadjuvant treatment (p=0.035) was an independent predictive factor of histological response.

Predictive factors of histological response would allow us to identify patients who would benefit most from neoadjuvant treatment. These patients with CRLM onset of more than 14 months and treated with CT combined with targeted therapy would be the best candidates for a neoadjuvant CT strategy followed by surgical resection.