Colorectal Cancer

Colorectal cancer develops due to genetic mutations in the cells of the colon or rectum, leading to uncontrolled growth and tumour formation.

• Lifestyle Factors:
  • Diet high in red and processed meats.
  • Sedentary lifestyle and obesity.
  • Smoking and excessive alcohol consumption.
• Medical Conditions:
  • Family history of colorectal cancer or inherited syndromes (e.g., Lynch syndrome).
  • History of polyps or inflammatory bowel disease (Crohn’s disease, ulcerative colitis).
  • Type 2 diabetes.
• Age and Genetics:
  • Risk increases after age 50.
  • Mutations in genes like APC, KRAS, and TP53.

In the early stages, symptoms may be mild or absent. As the disease progresses, the following symptoms can appear:

• Changes in bowel habits (diarrhoea, constipation, or stool narrowing).
• Blood in the stool or rectal bleeding.
• Abdominal pain or cramping.
• Unexplained weight loss.
• Fatigue and weakness.
• Persistent feeling of incomplete bowel evacuation.

The diagnosis of colorectal cancer involves a combination of the following:

• Screening Tests:
  • Colonoscopy: The gold standard for detecting polyps and tumours.
  • Faecal Occult Blood Test (FOBT) or Faecal Immunochemical Test (FIT): Detects hidden blood in stool.
• Imaging Studies:
  • CT Colonography (virtual colonoscopy).
  • MRI and CT scans for staging and detecting metastases.
• Biopsy: Tissue samples taken during colonoscopy to confirm cancer diagnosis.
• Blood Tests: EA (carcinoembryonic antigen) levels to monitor treatment response.

Treatment options depend on the stage, location, and patient factors:

• Early-Stage Cancer:
  • Polypectomy: Removal of polyps during a colonoscopy.
  • Endoscopic Mucosal Resection (EMR): For larger, localised tumours.
• Locally Advanced Cancer:
  • Surgery:
    - Open, Laparoscopic, or Robotic Approaches for tumour removal.
    - Total Mesorectal Excision (TME) for rectal cancer.
  • Neoadjuvant Therapy: Chemotherapy or radiotherapy before surgery to shrink tumours.
• Advanced Cancer:
  • Chemotherapy: Used to shrink tumours or as adjuvant therapy post-surgery.
  • Targeted Therapy: Monoclonal antibodies (e.g., bevacizumab) targeting cancer pathways.
  • Immunotherapy: For certain patients with high microsatellite instability (MSI-H).
  • Palliative Care: To manage symptoms and improve quality of life in metastatic cases.

• Neo-Adjuvant Chemo and Radiotherapy: Modern radiotherapy techniques have enabled sphincter-preserving surgeries for low rectal tumours, reducing the need for more invasive procedures like abdomino-perineal resection (APR), which often result in incontinence or stoma formation.
• Total Mesorectal Excision (TME): Introduced by Heald et al., this technique emphasizes precise dissection along the mesorectal plane, ensuring complete removal of vasculo-lymphatic pathways and reducing local recurrence. TME is pivotal for achieving optimal oncological outcomes.
• Complete Mesocolic Excision (CME) with Central Vascular Ligation (CVL): Hohenberger et al. extended the principles of TME to colonic cancers, emphasizing the removal of intact mesocolic tissue and extensive lymph node dissection. This approach has been associated with better oncological outcomes and reduced systemic disease spread.
• Laparoscopic Colorectal Surgery (LCS): Minimally invasive laparoscopic techniques have evolved significantly, offering comparable long-term outcomes to open surgery for colorectal cancer. Short-term benefits, including faster recovery, reduced pain, and shorter hospital stays, have been well-documented in multiple studies.

• Robotic Colorectal Surgery (RCS): Robotic surgery addresses many limitations of laparoscopy, such as restricted instrument mobility, tremor amplification, and the absence of three-dimensional vision. With robotic systems like the da Vinci Surgical System, surgeons gain enhanced precision, better ergonomics, and improved control over surgical instruments.

  Advantages of Robotic Surgery

  • Enhanced Precision: Greater maneuverability with EndoWrist instruments.
  • Improved Ergonomics: Surgeons experience reduced fatigue and better control.
  • Reduced Conversion Rates: Studies report conversion rates as low as 0–4.9%.
  • Positive Oncological Outcomes: Comparable or superior lymph node yields, low circumferential resection margin (CRM) positivity, and reduced local recurrence rates.

  Supporting Evidence for Robotic Surgery

  • Several prospective and retrospective studies validate the safety and efficacy of robotic colorectal surgery. For instance:
  • Long-term outcomes demonstrate three-year disease-free survival rates of 73.7% to 79.2% and overall survival rates of 92% to 97%.
  • Studies, including hybrid and fully robotic approaches, consistently show promising results for rectal cancer management.