This is your first fallacy. While toxins/harm can increase the risk of cancer it is not the sole cause of cancer.
Evert time a cell divides there is a risk of the process being less than perfect and errors occurring during the copying of DNA. Cancer happens when enough mutations of the right sort occur, taking the brakes off cellular reproduction and other control systems. That is why age, all by itself, increases the risk of cancer - the cells in the body of someone 80 have divided/reproduced so much more than the cells in someone say… 20.
But this sort of mutation disaster can happen at any age. There are even instances of babies being born already with cancer (fortunately, that is rare but it can and does happen). Early cancers include retinoblastoma and Wilms’ tumor.
Incorrect. A bad diet increases the risk of colon cancer but does not cause colon cancer.
Exposure to UV light is only one potential cause of skin cancer. Contact with certain chemicals can also do it.
Not sure where you get that one, either.
Another thing that does not cause cancer but can contribute to its spread is anything that suppresses the immune system.
Hormones, mostly, at least for breast tissue. Sex hormones cause cells in the gonads to go through various cycles of reproduction, over and over, and thus over the course of a lifetime those cells, due to so many divisions, are more prone to cancer than some others that divide less. That’s why one of the treatments for breast cancer is administering drugs that suppress sex hormones, so those cells are less stimulated and in many cases it can slow down cancer. Hormones are also why men become more and more prone to prostate cancer as they age… unless they’re castrated, something most men would rather not do. Again, one of the treatments for prostate cancer is hormone suppression.
Bone cancer is due, again, to cell turnover/reproduction. Your bones are not static, their components are constantly rebuilt and reinforced over and over a lifetime, so while bones may appear to be inert they aren’t, they’re very much alive.