Most likely the last one. As I understand it, our diagnosis techniques for cancer are very limited and basically only at the “omg, that’s obviously cancer” phas

Most likely the last one. As I understand it, our diagnosis techniques for cancer are very limited and basically only at the “omg, that’s obviously cancer” phase of progression (ie it has to be noticeable so that we can do a biopsy). Even our imaging techniques are limited because surgeries can discover that the cancer is worse than what was originally thought. In some cases we can catch the cancer very early, but even in those cases it’s a mixture of luck and we don’t actually know how long the cancer was actually growing for (“early” just means early enough for treatment to be very effective). At least that’s my external highly amateur understanding of the situation.