Colorectal cancer

Question 1

pathophysiology?

Answer 1

majority adenocarcinomas

Question 2

main affected site?

Answer 2

70% colon, 30% rectum

Question 3

Risk Factors?

Answer 3

• FH
• FAP
• HNPCC
• other cancers
• increasing age
• IBD
• diet (red meat, low fibre)

Question 4

Symptoms?

Answer 4

• change in bowel habit
  
  • usually to more loose and frequent stools
• PR bleeding
• tenesmus
• wt loss
• iron-deficiency anaemia
• bowel obstruction

Question 5

difference between how right and left sided lesions present?

Answer 5

• right sided
  
  • wt loss, anaemia
• left sided
  
  • PR bleeding, change in bowel habit, tenesmus

Question 6

Ix?

Answer 6

• Colonoscopy w biopsy - GOLD STANDARD
• CT colonography
  
  • CT w bowel prep & contrast to visualise colon
• CT thorax abdo pelvis to stage
• CEA blood test (tumour marker)

Question 7

Staging?

Answer 7

Dukes classification

A- confined to mucosa and part of muscle of bowel wall

B- extending through muscle of bowel wall

C- lymph node involvement

D- mets

can also use TNM

Question 8

Mx?

Answer 8

• surgical resection + chemo/radiotherapy
• palliative= relieving obstruction

Question 9

complications of surgery?

Answer 9

• DVT/ PE
• bleeding / infection/ pain
• damage to nerves, bladder or bowel
• post op ileus
• anastomotic leak/ failures
• adhesions
• hernias
• stoma

Question 10

when does the screening programme occur in scotland?

Answer 10

• >50 y/o
• every 2 years

Question 11

what is FAP?

Answer 11

autosomal dominant disorder of tumour suppressor APC gene - CRC develops if no treatment

Question 12

pathology of FAP?

Answer 12

hundreds/ thousands of adenomatous polyps throughout colon

Question 13

Rx of FAP?

Answer 13

prophylactic procto-colectomy & formation of ileal pouch

Question 14

what is HNPCC?

Answer 14

• Autosomal dominant disorder of DNA mismatch repair system
• Develop mainly right sided carcinomas
• V few polyps