malignancy vs metastasis

malignancy

noun
  • The state of being malignant or diseased. 

  • A malignant cancer; specifically, any neoplasm that is invasive or otherwise not benign. 

  • That which is malign; evil, depravity, malevolence. 

metastasis

noun
  • The spread of a harmful event to another location, like the metastasis of a cancer. 

  • Denying adversaries' arguments and turning the arguments back on them. 

  • The transference of a bodily function or disease to another part of the body, specifically the development of a secondary area of disease remote from the original site, as with some cancers. 

  • A change in nature, form, or quality. 

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