Colorectal cancer (CRC) is a common malignant tumor that primarily affects the elderly population. Surgery is one of the main treatment modalities for CRC. Frailty is a prevalent characteristic among the elderly and a leading cause of mortality. The frailty index (FI) is a comprehensive tool for assessing patients' frailty status, quantifying indicators such as weight loss, fatigue, and nutritional status, to reflect the degree of frailty. In recent years, the FI has undergone modifications to more accurately evaluate the risk of surgical complications and prognosis in CRC patients. This review summarizes the methods for frailty assessment, the development and modifications of the FI, and compiles the research findings and applications of the FI in predicting surgical complications, postoperative recovery, and survival rates in CRC patients. Furthermore, limitations in the current modified frailty index (mFI) and future research directions are discussed. This review provides essential references for further understanding the role of frailty in CRC patients and the clinical application of the mFI.
Keywords: colorectal cancer; frailty index; postoperative recovery; surgical complications; survival rates.