colorectal cancer Flashcards
define colorectal cancer?
● Malignant adenocarcinoma of the large bowel
what is the distribution of the positions of colorectal cancer?
● 40% - rectal
● 30% - sigmoid
● 5% - descending colon
● 10% - rest of colon
how can colorectal cancer be staged?
dukes staging
what are the three main types of colon cancer?
o Sporadic
o Hereditary non-polyposis colorectal carcinoma
o Familial adenomatous polyposis (FAP)
what is the amsterdam criteria?
used to assess which colorectal cancers are genetic:
o At least 3 family members with colon cancer
o The cases span at least 2 generations
o At least one case is diagnosed before the age of 50
risk factors of colorectal cancer?
o Western diet o Smoking o Colorectal polyps o Previous colorectal cancer o Family history o IBD o Chronic bowel inflammation
epidemiology of colorectal cancer?
- second most common cause of cancer death in the west
classical presentation of colorectal cancer?
- combination of anaemia with an abdominal mass
how does a left sided colon cancer present?
o Change in bowel habit
o Rectal bleeding
o Tenesmus
o Mass PR 60%
how does a right sided colon cancer present?
o Presents later o Anaemia symptoms o Weight loss o Non-specific malaise o Lower abdominal pain
how might a colon cancer present acutely?
o Large bowel obstruction
o Haemorrhage
signs of colorectal cancer on examination?
● Anaemia ● Abdominal mass ● If metastatic: o Hepatomegaly o Ascites ● Low-lying rectal tumours may be palpable on DRE
definitive diagnosis investigation for colorectal cancer?
● Endoscopy – diagnostic
o Sigmoidoscopy
o Colonoscopy
what might a double contrast barium enema show?
May show ‘apple core’ strictures
what might the bloods show?
● Bloods
o FBC - anaemia
o LFTs
o Tumour markers (CEA)
