• (n.) The act or state of becoming cancerous or growing into a cancer.
An obsolete term for a change that results in properties and features usually associated with malignant neoplasms, e.g., as in the development of a carcinoma in a site previously involved by a benign condition. ... (05 Mar 2000) ... 
Can`cer·a'tion noun The act or state of becoming cancerous or growing into a cancer.