The Collaborative International Dictionary of English v.0.48:

cancerous \can"cer*ous\, a. [Cf. F. canc['e]reux]
   Like a cancer; having the qualities or virulence of a cancer;
   affected with cancer; as, a cancerous growth. "cancerous
   vices" --G. Eliot.
   [1913 Webster] -- Can"cer*ous*ly, adv. --
   Can"cer*ous*ness, n.
   [1913 Webster]