Complete pathological response following neoadjuvant chemoradiotherapy in locally advanced colorectal carcinoma

Background: The prognosis of rectal cancer has improved with neoadjuvant treatment for locally advanced disease. Twenty percent of patients respond to treatment with complete pathological regression, which is clinically estimated with magnetic resonance imaging. Aim: describe the properties of the pathological complete response group of patients at our institution Materials and methods: All selected patients received LCCRT at the University Hospital for Tumors Sestre milosrdnice University Hospital Center, Zagreb, between January 2014 and December 2019 and were later surgically treated at the same facility. Results: We identified 23 patients with complete pathological responses, of which, despite surgery, seven progressed. We recorded a higher proportion of female patients in that group and younger age of onset. MRI preoperatively was not yet predictive of a complete pathological response. Conclusion: The proportion of patients with a complete pathological response is 16% in this cohort. All patients underwent surgery but did not receive consolidating therapy. About 30% progressed during the observed period.