Analysis of patients with complete histopathological tumour regression after neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Background: Our aim was to present the effect of the neoadjuvant chemoradiation therapy on the development of the complete histopathological tumour regression in patients with locally advanced rectal cancer and its influence on a five-year survival of these patients. Methods: In total, 223 patients were included in the analysis; 109 patients had the locally advanced rectal cancer; 75 patients received the neoadjuvant chemoradiation therapy, which was later followed by surgery; 34 patients were treated with the surgery alone. The surgical procedure was done 6 to 8 weeks after the chemoradiation therapy and it was preceded by haematology and biochemical analyses. In addition, patients were examined by ultrasound and MRI imaging of liver to evaluate the effects of neoadjuvant chemoradiation therapy. Accordingly, we had two patient groups: patients with the complete histopathological tumour regression and patients with the incomplete or no regression. We performed the statistical analysis of all locally advanced rectal cancer patients and determined their survival. Results: The complete histopathological tumour regression was found in 10.7% of 75 patients who were treated with preoperative chemoradiation. The down staging of the tumour appeared in 53.3% of patients. There were no stage changes in 21.3% of patients. The disease progressed into a more severe stage in 9.3% of patients, while the effects of the preoperative chemoradiation therapy could not be determined in 5.3% of patients. The survival of patients with the complete histopathological tumour regression was 70% in a five-year period, while it was 40% in patients with incomplete histopathological regression. Conclusion: The preoperative chemoradiation therapy leads to complete histopathological tumour regression and increases a five-year survival (70%). It also leads to the increase of the number of patients who undergo radical surgery.