Evolution does occur in cancer cells in the sense of increased genetic variability which may lead to more aggressive/resistant cancer in a patient. However we w

Evolution does occur in cancer cells in the sense of increased genetic variability which may lead to more aggressive/resistant cancer in a patient. However we won't see things like drug resistant staph infection because the genetics of the tumor don't spread beyond the individual. I also agree that our understanding of degenerative diseases is poor but I think that modern technology and methods will change this. Hopefully to the point were we can prompt the body to move the body from a diseased to a healthy state but that may be a ways out. However the genetic diversity in cancerous cells is not present in functioning human beings. Based on the analysis of genetic sequence data from tumor and blood samples from the same individuals it is clear that a large amount of mutation and structural variation occurs in cancer cells.