Colorectal adenocarcinoma

• 2^nd most common cause of cancer death in the UK

Predisposing factors;

• Neoplastic polyps
• UC, Crohn’s
• Familial adenomatous polyposis
• HNPCC
• Previous cancer
• Low fibre diet
• NSAIDs and aspirin may be protective

Presentation

• Depends on the side
• Left side
  • Bleeding/mucus PR
  • Altered bowel habit
  • Tenesmus
  • Mass PR
• Right side
  • Weight loss
  • Reduced Hb
  • Abdominal pain
• Either;
  • Abdominal mass
  • Obstruction
  • Perforation
  • Haemorrhage
  • Fistula

Tests

• FBC – microcytic anaemia
• FOB
• Proctoscopy sigmoidoscopy, barium enema or colonscopy
• LFTs
• CT/MRI
• Liver ultrasound
• CEA

Staging – Dukes classification

• A – confined to beneath muscularis mucosae
• B – extension through muscularis mucosae
• C – involvement of regional LN
• D – distant metastases

Spread

• Local
• Lymphatic
• Blood
• Transcoelomic

Treatment

• Surgery – aims to cure
• Right hemicolectomy – for caecal, ascending or proximal transverse colon tumours
• Left hemicolectomy – for tumoursof the distal transverse or descending colon
• Sigmoid colectomy – for tumours of he sigmoid colon
• Anterior resection – low sigmoid or high rectal tumours. Anastomoses are achieved at the first operation
• Andomino-perineal resection – for tumours low in the rectum, permanent colostomy and removal of the rectum and anus
• Radiotherapy can be given pre and post op to increase survival
• There is good evidence that chemotherapy (5-FU etc) increases survival in Stage C Dukes
• Patients with single lobe metastases and no extrahepatic spread may be suitable for curative surgery with liver resection

Prognosis

• 60% are amenable for radical surgery, of these 75% are still alive after 7 years

Polyps

• Lumps that appear above the mucosa
• There are 3 types;
  • Inflammatory – UC, Crohn’s and lymphoid hyperplasia
  • Hamartomatous – juvenile polyps, Peutz-Jegher’s syndrome
  • Neoplastic – tubulous or villous adenomas – malignant potential especially is >2cm
• Symptoms of polyps – blood/mucus PR