I'm sure CBT has been used with cancer patients, but pain management is not the heart of what CBT is about: http://www.beckinstitute.org/cognitive-behavioral-therapy/#q...

CBT is however about fixing negative thought patterns. Start of chapter 3 of Feeling Good (I just pulled open the pdf) Burns says 'Illogical pessimistic attitudes play the central role in the development and continuation of all your symptoms'

I don't think I myself have posted about this before, and just did a search. Hacker news does seem to be often dismissive of the psych field though, as there is not a lot of good science that would appease a critical thinker.