Transanal excision- Procedure: minimally invasive excision of small superficial tumors- Indications: early, localized disease (stage I)

Low anterior resection (LAR)- Procedure: sphincter-preserving resection of the rectum and sigmoid- Indications: locally advanced disease (Stage III-IV)- Total mesorectal excision (TME): en bloc excision of the mesorectum, regional lymph nodes, and vasculature- Resection 5 cm beyond the proximal margin of the tumor- Resection > 2 cm beyond the distal margin of well-differentiated tumors or > 5 cm beyond the distal margin of poorly differentiated tumors- Reconstruction (e.g., side-to-side anastomosis) and optional diverting ostomy

Abdominoperineal resection (APR)- Procedure: resection of the rectum, sigmoid, and anus with TME and permanent colostomy- Indications: last resort if the distal margin to the rectum cancer is < 2-5 cm to the anus

Systemic therapy- Neoadjuvant radiochemotherapy: locally advanced disease (stages II-III) typically followed by surgery and postoperative chemotherapy- Adjuvant chemotherapy after surgical resection depending on the pathologic work-up- Palliative chemotherapy: inoperable, metastatic disease (stage IV)

Follow-up:- Patient history, physical examination, CEA level: every 3-6 months for 3 years, then every 6 months for 2 years- Colonoscopy: after surgical resection, then 1 year after surgery, then every 3-5 years