You're right, DNA damage is just one of the types of genetic variation in cancer. There are many other structural variations that act like remixes.
"Maybe we need to start culturing and DNA testing cancers." I assure you this is being done at a massive scale.
Due to cellular stress, cancer cells disobey multi-cellular governance. They behave more like independent organisms fighting for survival, reverting to primal programming.
Oh I know we are trying to genomically test them for oncology research and potential treatment plans, but do they do paternity tests on them?
I was trying to remember which mammal in Australia gets tumors from fighting, and I found a reference to a mother getting melanoma from her daughter. It’s unclear to me whether the cancer transmission was rare or the identification is rare.
There’s very often a comparison to the somatic (i.e. non-cancer) genome of the same patient. It’s a great way to quality control that there wasn’t some sample mixup in the lab.
Transmission of cancer is rare in humans—if it were not, it would make someone’s career to find many cases of it. While we can’t say that all sheep are white, we’ve looked at enough of them to say that black sheep are not common. Furthermore, it’s very clear how the Tasmanian devil cancer is spread—it’s around the mouth while they are biting each others faces; it’s not as obvious how one would spread most human cancers.
Is HPV an example?
tasmanian devils [edit: I guess you already said that] https://en.wikipedia.org/wiki/Devil_facial_tumour_disease
Yup. Link is handy though. Someone will post it to the front page in 14 hours :)
The cancer problem always struck me as more of a control theory challenge than a purely biological one.