Treating cancer a doc gets agreement (10)
I believe the answer is:
accordance
'agreement' is the definition.
(accordance is a kind of agreement)
'treating cancer a doc' is the wordplay.
'treating' is an anagram indicator.
'cancer'+'a'+'doc'='canceradoc'
'canceradoc' is an anagram of 'ACCORDANCE'.
'gets' acts as a link.
(Other definitions for accordance that I've seen before include "(In) conformity (with)" , "Agreement" , "Keeping" .)