AMC 2 Flashcards
Commonest GIT malignancy: mainly adenocarcinoma
Colorectal cancer
Second most common cause of death from cancer in Western society
Colorectal cancer
Generally men over 50 years (90% of all cases)
Colorectal cancer
Two-thirds in descending colon and rectum
Colorectal cancer
Colorectal cancer Predisposing factors
Ulcerative colitis (longstanding)
Familial: familial adenomatous polyposis (FAP), hereditary non-polyposis colorectal cancer
Colonic adenomata
Decreased dietary fibre
Age >50 years
Alternating constipation with spurious diarrhoea
Colorectal cancer
Unsatisfactory defecation
Colorectal cancer
Rectal examination—this is appropriate because many cancers are found in the lowest 12 cm
and most can be reached by the examining finger
Colorectal cancer
If obstructing, there is a risk of rupture of the caecum.
Colorectal cancer
Spread
Lymphatics → epigastric and para-aortic nodes
Direct → peritoneum
Blood → portal circulation
Colorectal cancer
FOBT: immunochemical tests (e.g. Inform and InSure) do not require dietary or medication
restriction
Colorectal cancer
Colonoscopy ± biopsy
CT colonography (investigation of choice)
Serum CEA level
Colorectal cancer
Ultrasonography and CT scanning not useful in primary diagnosis; valuable in detecting
spread, especially hepatic metastases
Colorectal cancer
PET-CT scanning (if available) is useful for follow-up
Colorectal cancer
If FOBT is positive—investigate by colonoscopy or by flexible sigmoidoscopy.
Colorectal cancer
An FOBT every 2 years is now recommended for all people from 50–74 years
Colorectal cancer
FOBT is safer, cheaper and more convenient than colonoscopy.
Colorectal cancer
Do not use the
CEA blood test as a screening tool.
Colorectal cancer
Colonoscopy as screening is only recommended in 2% of the population
Colorectal cancer
Moderate risk (family history category 2): 2 yearly FOBT from 40–49, then colonoscopy
every five years from 50–74 years.
Colorectal cancer
High risk (family history category 3): 2 yearly FOBT from 35–44, then colonoscopy every 5
years from 45–74 years
Colorectal cancer
flexible sigmoidoscopy and rectal biopsy for those with ulcerative colitis
Colorectal cancer
Refer to a bowel cancer specialist to plan appropriate surveillance
Colorectal cancer
Early surgical excision is the treatment, with the method depending on the site and extent of the
cancer
Colorectal cancer