1 Introduction Rectal cancer is a common malignancy of the gastrointestinal tract. Compared with gastric cancer, which has a 5-year survival rate of 35.7%, and pancreatic cancer, with a 5-year survival rate of 13%, rectal cancer demonstrates a relatively favorable prognosis, with a 5-year survival rate of approximately 67% (1–6). However, clinical data indicate that nearly 20% of patients with colorectal cancer present with distant metastasis at initial diagnosis.
