Early colorectal cancers refer to invasive cancers that have infiltrated into the submucosa without invading muscularis propria, and approximately 10% of these patients have lymph node metastases that cannot be detected by conventional imaging. According to the guidelines of Chinese Society of Clinical Oncology (CSCO) Colorectal Cancer, early colorectal cancer cases with risk factors for lymph node metastasis (poor tumor differentiation, lymphovascular invasion, deep submucosal invasion and high-grade tumor budding) should receive salvage radical surgical resection; however, the specificity of this risk-stratification is inadequate, making most patients undergo unnecessary surgery. Firstly, this review focuses on the definition, oncological impact importance and controversy of the above "risk factors". Then, we introduce the progress of the risk stratification system for lymph node metastasis in early colorectal cancer, including the identification of new pathological risk factors, the construction of new risk quantitative models based on pathological risk factors, artificial intelligence and machine learning technology and the discovery of novel molecular markers associated with lymph node metastasis based on gene test or liquid biopsy. Aim to enhance clinicians' understanding of the risk assessment of lymph node metastasis in early colorectal cancer; we suggest to take the patient's personal situation, tumor location, anti-cancer intention and other factors into account to make individualized treatment strategies.
早期结直肠癌是指浸润至黏膜下层而未侵犯固有肌层的结直肠腺癌，约10%的早期结直肠癌患者存在常规影像学检查未能发现的淋巴结转移。根据中国临床肿瘤学会CSCO结直肠癌诊疗指南的推荐，建议具有淋巴结转移“高危因素”的患者接受补救性根治术，包括肿瘤分化差、肿瘤侵犯脉管、黏膜下层深度浸润和高级别肿瘤出芽等，但该评估体系特异度不理想、易造成大部分患者接受不必要的手术切除。本文重点阐述上述“高危因素”的定义、肿瘤学意义以及学术争议；其次，本文还介绍早期结直肠癌淋巴结转移风险评估体系的最新研究进展，包括新的病理学高危因素的鉴定，基于病理学高危因素的新型淋巴结转移风险量化模型的构建，基于肿瘤基因检测与液体活检技术的淋巴结转移相关分子标记物的发现以及基于人工智能以及机器学习的淋巴结转移风险评估模型的构建。旨在强化临床医生对早期结直肠癌淋巴结转移风险评估的客观认识，建议综合考虑患者个人情况、肿瘤位置和抗癌意愿等因素，个体化地制定治疗策略。.