[Application of perioperative chemotherapy in locally advanced colorectal cancer]

Perioperative chemotherapy is the major component of therapeutic approaches in multidisciplinary team (MDT) of colorectal cancer. In resectable colorectal cancer, the role of systemic chemotherapy is more important. In resectable colon cancer, especially locally advanced high-risk T3 or T4 tumor, perioperative chemotherapy can confer downstaging of primary tumor, improve pathologic complete response (pCR) rate and postoperative tumor regression. However, long-term oncological outcomes need prolonging follow-up period and phase III randomized controlled trials to confirm. On the basis of standard of care with chemoradiation followed by surgery, total neoadjuvant threapy (TNT) strategy is suggested in locally advanced rectal cancer. Addition of systemic chemotherapy before or after chemoradiation showed advantages of more completion of neoadjuvant chemotherapy, high percentage of delivering drugs dosage, good compliance and tolerance. The trend toward higher pCR rate was also observed in TNT strategy. Neoadjuvant chemotherapy without chemoradiation had similar long-term efficacies compared with concurrent chemoradiation, with avoiding functional impairment and secondary cancers. In brief, perioperative chemotherapy plays a very important role in MDT of colorectal cancer.