Colorectal cancer Flashcards
Epidemiology of colorectal cancer
1 in 20 people will be diagnosed in their lifetime but the survival rate is 60% or over for both colon and rectal cancer.
What is the pathogenesis of colorectal cancer?
- Begins with benign polyps (resulting from hyperproliferation)
- This then progresses into adenocarcinoma
- Adenocarcinoma can turn into a more invasive tumour
Where in the colon/rectum do cancers mostly occur?
Cancer is more likely to develop in the left side of the colon and the rectum.
38% in the rectum
21% sigmoid colon
What are the red flag symptoms that are indicative of colorectal cancer?
- Rectal bleeding
- Change in bowel habit e.g. intermittent constipation and diarrhoea
- Abdominal pain
- Mucous in rectal bleeds
- Anorexia and weight loss (unexplained)
What are other potential causes of PR bleeding other than cancer?
- Anal fissure
- Haemorrhoids
- Gastroenteritis
- Trauma
- Anticoagulants
What does the 2 week wait urgent referral to secondary care entail?
- Colonoscopy and flexi sigmoidoscopy
- Colorectal surgeon review
Screening programme for colorectal cancer
For patients aged 60-74 years old, every 2 years they have to do a Faecal immunochemical test.
Bowel screening scope e.g. sigmoidoscopy at age 55. One off test to detect left sided polyps. If normal, bowel screening as normal when turn 60.
What investigations are done to reach diagnosis?
- Colonoscopy
- CT abdomen
- MRI rectum is gold standard as you can see the soft tissue in more detail and allows for pelvic staging
Colon cancer management
Neoadjuvant chemotherapy if predicted that the tumour has locally advanced.
Hemicolectomy and anterior resection.
Rectal cancer management
Local recurrence is common
If low risk, anterior resection/hartmann’s is performed without neoadjuvant
If moderate risk, radiotherapy then surgery
If high risk, both chemo and radiotherapy followed by surgery
Why is neoadjuvant chemotherapy used?
Neo-adjuvant chemotherapy with Oxaliplatin and 5FU was found to be safe, had less major post-op morbidity, down staged tumours and there were fewer incomplete resections.
