brief summary：Pathologic analysisEach tumor resection specimen was reviewed by twoindependent pathologists Songran Liu and Shixun LuAll cases were pathologically staged referring to the 8thedition of

The pathologic analysis of tumor resection specimens involved two independent pathologists who reviewed each case. The tumors were staged according to the 8th edition of the AJCC staging system. Hematoxylin and eosin staining was used to assess the lymphovascular invasion (LVI) status, and the presence of tumor cells within small endothelium-lined lymphatic or vascular channels indicated LVI. Perineural invasion (PNI) was diagnosed when tumor cells invaded, surrounded, and penetrated nerves and nerve sheaths. The analysis also included evaluating the statuses of proximal and distal margins, lymph node metastasis, tumor differentiation, following current guidelines.