Colorectal Carcinoma Flashcards
Define colorectal carcinoma
malignant adenocarcinoma of the colon
What are the causes/risk factors of colorectal carcinoma?
• Increasing age
• Familial adenomatous polyposis (FAP) – APC mutation, autosomal dominant
• Hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome) –
microsatellite instability, autosomal dominant
• MYH-associated polyposis
• Peutz-Jeghers syndrome – benign hamartomatous polyps in GIT and
hyperpigmented macules on the lips and oral mucosa, autosomal dominant
• Inflammatory bowel disease
• Obesity
• Diet – lack of fibre, high in red meat
What are the symptoms of colorectal carcinoma?
- Change in bowel habit
- Abdominal pain
- Fresh PR bleeding
- Blood or mucus mixed with stools
- Tenesmus
- Anaemia (lethargy, SOB)
- Weight loss
What are the signs of colorectal carcinoma?
- Rectal mass
- Anaemia (pallor)
- Bowel obstruction
Metastases
• Hepatomegaly
• Ascites (shifting dullness)
Red Flags for Colorectal Carcinoma:
• Change in bowel habits
• PR bleeding
• Unexplained Fe-Deficiency Anaemia
What investigations are carried out for colorectal carcinoma?
- FBC - often shows iron deficiency anaemia.
- U&Es- normal
- LFTs - usually normal, even in the presence of liver metastases
- CEA (carcino-embryonic Antigen) - tumour marker; monitors the efficacy of therapy and recurrence of the tumour
- AXR - may be normal or show signs of large bowel obstruction
- CXR - often normal; may show a pneumoperitoneum in an erect CXR if there is perforation
- Sigmoidoscopy/ Colonoscopy - visualisation the lesion
- Biopsy for pathological confirmation.
- CT/ Virtual Colonography
- Barium Contrast Enema - ‘Apple core’ stricture on barium enema.
- CT Scan - CT chest, abdomen and pelvis. Allows for the visualisation of the mass and any metastases for staging
- Liver USS - liver masses (metastases). Allows for staging
- PET Scan - focal ‘hotspots’ in regions with metastases. Allows for staging
