I don't think you appreciate what mechanical_fish was trying to communicate.

First off, the comparison to Hitler is not hyperbole or misapplied metaphor. Hitler literally compared the Jews to cancer, please see: http://www.dailymail.co.uk/news/article-1233707/Hitlers-hatr...

Second, it's not clear to me that you do appreciate mechanical_fish's feelings. His point is that cancer is an outsized, heavy word, and regardless of the author's intent, the word has connotations that neither you nor the author can shake loose from the word.