cameo vs title role

cameo

noun
  • A piece of jewelry, etc., carved in relief. 

  • A single very brief appearance, especially by a prominent celebrity in a movie or song. 

verb
  • To appear in a cameo role. 

title role

noun
  • The part of a movie, play, or television show, from which the work's title is taken. 

How often have the words cameo and title role occurred in a corpus of books? (source: Google Ngram Viewer )