Colorectal Cancer Flashcards
Do more colonic cancers arise on the left or the right side?
More on the left
Only ~25% on the right
WHat pre-existing lesion in the colon can transform into colonic cancer?
pre-existing adenomatous polyps
How long does it take for polyps to transform into cancer?
Average 3-5 years
- can be up to 10
WHat increases a patient’s risk of getting colonic cancer?
- Older age
- Low intake of fibre
- High intake of fat, sugar, alcohol, red meat, processed meats
- Obesity
- Smoking
- Lack of physical exercise
WHat genetic mutations can predispose patients to bowel cancer?
Mutations in APC (adenomatous polyposis coli)
- 100% risk
OR Mutations of p53 gene
What pre-existing conditions can increase a patient’s risk of colon cancer?
- Long standing IBD
UC > Crohn’s
How can bowel cancers spread?
- Direct spread
- Lymphatic spread
- Blood borne spread
- Transcoelomic spread (rare)
Where do bowel cancers commonly metastasise to?
Liver
Lung
Describe the Bowel Screening programme operated in the UK to pick up Bowel Cancer early
In Scotland – 50-72 years
In England 60-72
- Every 2 years patient invited to give stool sample
- If positive – offered colonoscopy
What symptoms usually indicate a left sided cancer?
- Rectal bleeding
- Feeling of incomplete emptying
- Worsening constipation
What symptoms can indicate a right sided colon cancer?
- Unexplained Iron deficiency anaemia
- Persistent tiredness
- change in bowel habit
- weight loss
- Abdominal pain (colicky in nature)
- Lump in the abdomen
What investigations can be used in an attempt to diagnose a bowel cancer?
Barium enema (widely abandoned) Sigmoidoscopy OR `colonoscopy CT colonography
What happens after colon cancer is diagnosed?
- Biopsy for Histology confirmation
- Cancer staging (CT chest/abdo/pelvis)
- MRI for rectal cancers
- MDT
- Surgery/ palliation
What percentage of colonic cancer is diagnosed at Stage I and II?
40%
therefore more are diagnosed at Stage 3 or above
If a tumour is found in the caecum, what type of surgery can remove the tumour?
Right Hemicolectomy
- caecum to hepatic flexure removed
- ileocolic anastomosis made
If a tumour is found on the RHS near the hepatic flexure, what type of surgery can be used to remove it?
Extended right hemicolectomy
- Right colon and part of transverse colon removed
- ileocolic anastomosis made
If a tumour is found in the transverse colon only or the sigmoid colon only, how is it removed via surgery?
Transverse colectomy
- anastomosis made in transverse colon
Sigmoid colectomy
- anastomosis made in sigmoid colon
If a tumour is found in the rectum, what are the two surgical options depending on its anatomical location?
Tumour in SUPERIOR rectum
- anterior resection
- small part of lower rectum remains to anastomose to colon
Tumour in INFERIOR rectum
- anus resected, perianal skin closed
- colostomy made
After a tumour is removed during surgery, what staging criteria is used in Pathology?
Duke’s Staging
After resection of colorectal cancer, what other treatment may a patient require?
Chemotherapy
Radiotherapy
How are patients with colorectal cancer followed up?
- CT
- CEA (antigen to test how well Tx is working)
- Colonoscopy
What is involved in management of advanced colorectal cancer?
- Cancer resection + chemo
- May also need liver + lung resection
- HIPEC ( hyperemic intraperitoneal chemotherapy) for mesothelioma, pseudomyxoma peritonei and peritoneal metastasis
What is involved in palliation for colorectal cancer?
- Stenting
- Palliative radio/chemotherapy
- bypass
