In studies of cancer, only the Cancer category should be used - do not code for the site.
This is in line with the coding guidance to assign health categories based on the main disease - not pathogenesis or site of action.
However if the research involves studying a condition that predisposes to cancer, it may be appropriate to also code for the condition
Cancer is not a 'normal' process and hence studies that specifically relate to the cause of cancer are rarely coded within the 1 Underpinning code group.
In particular studies of abnormal cell cycle or DNA repair in relation to cancer should not be coded within the 1 Underpinning code group.