Surgical Treatment of Rectal Carcinoma
Surgical resection by an experienced surgeon with total mesorectal excision (TME) is the cornerstone of curative treatment for rectal cancer, with sphincter preservation attempted whenever oncologically feasible. 1, 2
Standard Surgical Approach for Localized Disease
The fundamental surgical standards include: 1
- Surgical resection performed by an experienced surgeon
- Pathological examination of the operative specimen
- Sphincter preservation if at all possible
- Complete excision of the mesorectum for sub-peritoneal tumors 1, 3
Total Mesorectal Excision (TME) Technique
For tumors of the lower third of the rectum, excision of the entire mesorectum is essential to reduce locoregional recurrence risk. 2, 3 The surgical technique requires: 4
- Excision of the envelope of rectal mesentery posteriorly and supporting tissues laterally from the sacral promontory to the pelvic floor
- Achievement of at least 1 cm distal margin 5
- Harvesting and analysis of 12 or more regional lymph nodes 5
- Careful clearance of the radial margin 5
Sphincter-Preserving vs. Abdominoperineal Resection
Sphincter preservation should be attempted whenever possible, depending on tumor location relative to the sphincter, tumor volume, and patient anatomy. 1, 2 The decision algorithm is: 3, 6
- Low rectal tumors: Radical resection (abdominoperineal resection, APR) is usually required for tumors of the lower third when sphincter preservation is not feasible
- Mid/upper rectal tumors: Anterior resection (AR) or ultralow anterior resection with or without intersphincteric resection (ISR) can be performed
- When performing APR: Epiplooplasty to fill the perineal wound is recommended to reduce complications 3
Neoadjuvant and Adjuvant Therapy Integration
For Clinical Stage II/III Disease
Total neoadjuvant therapy (TNT) is now the preferred approach, delivering both chemoradiotherapy and chemotherapy before surgery. 2 The treatment sequence is: 2, 7
- Preoperative external beam radiotherapy (50.4 Gy with concurrent 5-FU-based therapy) is an option 1, 7
- Surgery performed 6-8 weeks after completion of neoadjuvant treatment 7
- For Dukes C disease (node-positive): Postoperative chemotherapy with 5-FU + folinic acid is recommended 1, 7
A critical pitfall: Exclusive chemoradiation without surgery is not safe for infiltrative rectal carcinoma—80% of patients with apparent complete clinical response after chemoradiation developed local recurrence within 9 months when surgery was omitted. 8
Surgical Management of Metastatic Disease
Resectable Metastases
Simultaneous rectal and hepatic surgery is standard if the hepatectomy involves 3 or fewer segments. 1 Alternative options include: 1
- Hepatectomy 3 months after rectal surgery depending on extent of progression
- Pulmonary surgery 3 months after rectal surgery depending on assessment of disease spread
- Neoadjuvant chemotherapy (inclusion in therapeutic trials is recommended)
- External-beam radiotherapy should be considered if complete resection of the rectal tumor is achieved
Non-Resectable Metastases
For multiple synchronous symptomatic metastases, systemic palliative chemotherapy is the standard treatment. 1, 7 First-line options include: 7
- 5-FU/leucovorin with oxaliplatin (FOLFOX) or irinotecan (FOLFIRI), with or without targeted agents
Specific local treatment depends on clinical situation: 1
- Surgery for stoma formation
- Radiotherapy
- Laser therapy
- Chemotherapy plus radiotherapy
Prognostic Factors Guiding Surgical Decision-Making
Primary prognostic factors that determine adjuvant therapy include: 3
- Presence/absence of distant metastases
- Type of rectal surgery performed (curative vs. palliative)
- Extent of bowel wall infiltration
- Invasion of adjacent organs
- Presence/absence of metastatic locoregional nodes
If resection is microscopically incomplete and/or metastatic nodes present and/or invasion of perirectal fat: External-beam radiotherapy (minimum 50 Gy) followed by consideration of additional surgery is recommended. 1, 3
Follow-Up Protocol
Standard follow-up examinations include: 1, 2
- Clinical examination
- Chest X-ray
- Liver ultrasound
- Colonoscopy
If sphincter-preservation surgery was performed: Rectoscopy and/or endorectal ultrasonography should be considered. 1, 2, 3
Important caveat: CT scanning and MRI are not indicated as routine examinations in follow-up. 1 Liver function tests and markers must not be measured routinely, though CEA monitoring can help detect recurrence when confirmed by repeat testing after minimum 1-month interval. 3
Critical Pitfalls to Avoid
- Inadequate mesorectal excision for lower third tumors leads to higher local recurrence rates 3
- Omitting surgery after apparent complete response to chemoradiation results in 80% local recurrence rate 8
- Failure to consider postoperative radiotherapy when surgical clearance is incomplete or tumor was under-staged preoperatively 3
- APR without proper technique has problems with high rates of tumor perforations and positive circumferential resection margins 6