Rectal Cancer — Overview

Rectal cancer arises from the inner lining of the rectum — the last 12–15 cm of the large intestine before the anal canal. It is distinct from colon cancer in its management due to the proximity of the sphincter, the narrow pelvis, and the need for neoadjuvant treatment. MRI staging is essential for treatment planning.

Staging & Treatment Planning

• MRI Rectum — essential for local staging; assesses T stage, N stage, circumferential resection margin (CRM) and extramural vascular invasion (EMVI)
• CT Chest/Abdomen/Pelvis — distant staging
• Multidisciplinary Tumour Board — all rectal cancers discussed by surgeons, oncologists, radiologists and pathologists at Charak Hospital

Treatment Pathways

• Early (T1–T2 N0) — upfront surgery; Low Anterior Resection (LAR) with TME for most; transanal excision for very early T1 lesions
• Locally Advanced (T3–T4 or N+) — neoadjuvant long-course chemoradiation (45–50 Gy with capecitabine) followed by surgery 6–8 weeks later; improves resectability and sphincter preservation rates
• Complete Clinical Response — "Watch and Wait" (non-operative management) for patients with complete tumour disappearance after chemoradiation; surveillance with MRI, endoscopy and CEA