Editing Colon cancer (section)

== '''Screening''' ==

** NBSCP
*** FOBT 2-yearly between 45 and 74
**** Two samples each time
**** iFOBT (now used for NBCSP): immunochemical test which identifies only human haemoglobin
**** gFOBT: The samples placed in a hydrogen peroxide solution. If haem is in the stool sample, there will be pseudoperoxidase activity, and oxygen will be released from the hydrogen peroxide in the ensuing reaction. A card containing guiac resin is placed in the solution, and if oxygen is present, the guiac will be oxidised to a different colour. Thus, the guiac changes colour if haem is present. False positives can occur with dietary red meat, vitamin C and anti-inflammatories for three days prior.
**** Can also be ok to use as screening tool in 50-74 year olds with abdo pain/weight loss/fe-defic anaemia
*** For pre-cancerous adenoma detection: 90.6% sp / 33.9% se
*** For early CRC: 89.8% sp / 84.6% se
*** Positive FOBT:
**** 58% normal colonoscopy
**** 39% polyp
**** 10% advanced adenoma >1cm
**** 3% CRC
*** Benefits:
**** 9% disease-specific mortality vs 24%
**** 2300-3200 deaths prevented each year in Australia
** If positive - should proceed to colonoscopy within 120 days


[[Category:Colorectal]]
[[Category:Intern education]]