[Clinical research progress on disappearing colorectal liver metastases]

Colorectal cancer is currently one of the most common digestive system tumors, and the liver is the most common metastatic site of colorectal cancer. In recent years, with the continuous development of the multidisciplinary treatment for colorectal cancer patients, there are quite a few cases of disappearing liver metastases (DLM) after receiving preoperative chemotherapy (or combined targeted drug therapy), and the diagnosis and treatment of DLM is currently still a very challenging and controversial topic. This article sorts out the related researches on DLM in recent years, mainly including the following 4 aspects: (1) The factors associated with DLM, including the size and number of liver metastases, chemotherapy regimens and cycles, targeted therapy drugs, and the pattern of liver metastases, Ras/Braf status and the location of the primary lesion. (2) The relationship between DLM and true complete response (pathological complete response and persistent clinical complete response), and the related predictive factors of pathological complete response. (3) Clinical evaluation of DLM: preoperative evaluation includes ultrasound, CT, MRI, and PET, while intraoperative evaluation includes intraoperative exploration, intraoperative ultrasound, and augmented reality. (4) DLM treatment strategies, including surgical treatment, local treatment, non-surgical treatment and individualized treatment.