Perioperative chemotherapy in patients with colorectal cancer liver metastasis

The incidence of colorectal cancer liver metastasis (CRLM) increased gradually in recent years. Surgical resection is the most important treatment for CRLM patients to obtain long-term survival, with a 5-year survival rate of about 50%. However, only 20% of the CRLM patients are initially resectable. The recurrence rate after surgery is more than 70%. Perioperative chemotherapy has been widely used with the development of effective chemotherapy regimens and targeted therapies. For patients with initially resectable liver metastases, perioperative chemotherapy may help reduce recurrence and prolong survival. For patients with unresectable liver metastases, conversion chemotherapy with high efficiency provides opportunity for radical resection. However, CRLM is a disease with high heterogeneity and with many factors influencing prognosis, and there is a lack of large-scale prospective clinical trial evidence in many problems. Hence there are still many controversies in the clinical practice of perioperative chemotherapy, including whether chemotherapy alone is the best preoperative treatment for resectable CRLM, whether preoperative chemotherapy combined with targeted therapy is superior to chemotherapy alone, who can benefit most from preoperative chemotherapy combined with targeted therapy, who are the exact patients suitable for conversion therapy, how to choose the best first-line conversion therapy. Here we discuss the current status of research on perioperative chemotherapy in three aspects: neoadjuvant chemotherapy, conversion therapy and adjuvant chemotherapy. We also emphasized the importance of multidisciplinary team during the treatment process to give patients individualized therapy considering their specific conditions. Key words: Colorectal neoplasms; Metastasis, liver; Surgery; Chemotherapy