[Strategies and challenges in the diagnosis and treatment of colorectal cancer peritoneal metastasis].

Peritoneum is a common metastatic site of colorectal cancer and has worse prognosis compared with other metastatic sites. Peritoneal metastasis was previously considered as a terminal state of the disease, and palliative treatment with systemic chemotherapy was the main treatment method. With the gradual acceptance of the cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) treatment model by surgeons and the application of targeted and immunotherapeutic drugs, the prognosis of patients with colorectal cancer peritoneal metastasis has been greatly improved. However, the diagnosis and treatment of peritoneal metastasis still face many challenges and controversies. Based on the evolution of the understanding of colorectal cancer peritoneal metastasis, the possible mechanisms of peritoneal metastasis are discussed, including the theory of "oligometastases" and the theory of "seed and soil". Besides, we further investigate the diagnosis and treatment strategies of colorectal cancer peritoneal metastasis and the facing challenges, including the limitations of imaging examination, the controversy of laparoscopic exploration, the difficulty in assessing peritoneal metastatic load, the limited means of postoperative recurrence monitoring and efficacy evaluation, and the significant variation in the diagnosis and treatment level among different regions of China. Meanwhile, we emphasize the importance of multidisciplinary perioperative management of CRS+HIPEC, and propose that the basic and clinical transformation research of peritoneal metastasis should be strengthened, and the promotion of standardized diagnosis and treatment of peritoneal metastasis is the key to improve the prognosis of patients with colorectal cancer peritoneal metastasis.