[Significance of Conversion Surgery in Colorectal Cancer]

Advances in chemotherapy, including molecular-targeted agents, have led to reports of cases of colorectal cancer that are amenable to radical resection after systemic chemotherapy. However, there is no consensus on the optimal treatment to achieve such conversion surgery(therapy). Interpretation in clinical trials is complicated by patient heterogeneity due to prognostic features such as the presence or absence of RAS/BRAF mutations, lack of consensus on unresectable criteria, and lack of data on clinical outcomes of secondary resection. Results of a systematic review based on the results of randomized controlled trials of drug therapy indicate an actual conversion surgery rate of less than 10%, with a limited prognostic benefit when R0 resection is achieved. Prospective studies with clearly defined uncertainties are needed to clarify the significance of conversion surgery in colorectal cancer.