[Progress and prospect of standardized diagnosis and treatment for left-sided colon cancer]

Due to the complex anatomical structure, high variability of vasculature, and substantial controversies regarding treatment decision-making in left-sided colon cancer, standardized diagnosis and treatment has remained a research focus in the field of colorectal surgery. This article systematically reviews the core advances and clinical standards in the surgical management of left-sided colon cancer. The discussion encompasses the definition of the left colon and its special anatomical significance, the principles of surgical dissection of the left colonic mesentery, fascia, and interfascial spaces under the framework of membrane anatomy, the indications and technical essentials of totally intracorporeal digestive tract reconstruction, and the indications, extent, and nerve-sparing strategies for dissection of No. 223 and No. 253 central lymph nodes. A decision-making pathway for individualized bowel resection extent based on tumor location is proposed. The clinical value of the sequential "colonic stent for obstruction--neoadjuvant chemotherapy--radical surgery" treatment paradigm for obstructive left-sided colon cancer, as well as the indications and oncological benefits of multivisceral resection for cT4b left-sided colon cancer, are clarified. Targeted recommendations are also provided for special clinical scenarios, including additional radical surgery after endoscopic resection of early-stage cancer and the management of synchronous multiple primary tumors. This review aims to summarize the current progress and consensus in the diagnosis and treatment of left-sided colon cancer, offering a reference for establishing a comprehensive, standardized clinical system covering anatomical cognition, surgical techniques, and complex case management, with the goal of achieving a balance between oncological radicality and organ function preservation, thereby improving patients' long-term survival and quality of life.