Locally Advanced Rectal Cancer - Radiation Response Prediction Study - Serum Proteins

The study objective was to find new biomarkers of treatment response and adverse events in patients receiving neoadjuvant therapy for locally advanced rectal cancer. Patients received neoadjuvant chemotherapy (NACT) followed by chemoradiotherapy (CRT) and underwent treatment evaluation four weeks after CRT completion. Radical pelvic surgery was planned 2-4 weeks later. Patients were scored for treatment adverse events, according to Common Terminology Criteria for Adverse Events (CTCAE) version 3.0, throughout the neoadjuvant treatment course, including at NACT and CRT completion. Treatment response was assessed by histologic ypTN staging and tumor regression grade (TRG) scoring, as well as progression-free survival (time from Inclusion date to Date of local relapse or Date of metastatic disease, whichever came first) recorded for five years after surgery. From 80 study patients, serial serum samples were collected at baseline (Sampling point=1), following NACT (post-NACT; Sampling point=2), at CRT completion (post-CRT; Sampling point=4), and at treatment evaluation (Sampling point=5). The samples were analyzed with a high-density antiboly array (AHH-BLG-1; RayBiotech Inc.) for the presence of 507 proteins.