Colorectal cancer Flashcards
Genetic risk factors for colon cancer
Tumour suppressor genes:
- Adenomatous polyposis coli gene - APC
- K - RAS
- p-53
Risk factors for colon cancer
Age
Male
IBD
FHx
Smoking
Red meat
Low fibre diet
Obese
Familial adenomatous polyposis - FAP
Hereditary non polyposis colon cancer - HNPCC (lynch disease)
Where is colon cancer likely to spread
Liver
Rectal carcinoma - lungs
Presentation of ascending colon cancer
Abdominal pain
FLAWS
More insidious therefore late diagnosis
Iron deficiency anaemia
Presentation of descending colon cancer
Constipation
Bloating
Abdo pain - colicky
FLAWS
Heamatochezia
Napkin ring constrictions
Descending colon cancer is more likely due to an infiltrating mass which causes lumen narrowing
Investigations for colon cancer
PR exam
Bloods - FBC, U+Es, LFT, CRP, Fe2+, CEA
Colonoscopy and biopsy
Fecal occult blood tests - for GI bleeds
Barium enema - AXR
CTPA/PET
Signs of colon cancer on barium enema AXR
Apple core sign - constriction of lumen
Treatment
Early - surgical resection with a stoma - colectomy
Lymph node spread - chemotherapy
Metastatic - palliative chemo or surgery
Epidemiology of colon cancer
2nd most common cancer
Presentation of rectal carcinoma
Bright red blood in stool
Tenesmus
FLAWS
Abdo pain
Staging colon cancer
Modified Dukes staging
Right sided or transverse colon cancer surgery
Right hemicolectomy
or extended hemicolectomy
Left sided colon cancer surgery
Left hemicolectomy
Sigmoid or upper rectum colon cancer surgery
High anterior resection
