I'm not sure you are asking the right question. Prostate cancer is routinely checked for once you hit a certain age, so that would seem to go against your premise. Breast cancer would be equivalent to prostate cancer in that it typically happens after a certain age and they usually want to check for that once you hit that age at your yearly checkups.
I know testicular cancer does happen, many times to younger aged men, but isn't it quite easy to spot? Typically a swollen lump in the scrotum that would be more obvious than some other forms?
I think it's something that sucks when it happens, but I don't think it's that common. Something else when it comes to cancer is that people think it's something that is inevitable if you have bad genetics but that simply isn't true. There is no way to guarantee you Won't get cancer, but there are a lot of ways to minimize your risks. Eating right(green leafy vegetables), exercising, ensuring you have proper vitamin D levels, maintaining a healthy body composition, taking turmeric and cumin regularly, Vitamin K2, etc. all lead to getting your risk as low as possible.
I'm not saying this was you at all, but the thing that really irritates me is to see people who seemingly eat like crap for 30 years, don't exercise, weigh 290 lbs, then act shocked when they get cancer. Well no sh!t dumbass, you basically did everything to ensure you got it rather than do everything to try and prevent it. And there is no guarantee they wouldn't have gotten it based on genetics, but cancer isn't typically something that just pops up out of nowhere...it's decades in the making normally, chronic levels of inflammation over many years that go unchecked leading to more and more serious issues and finally to cancer.
Again, you can't prevent it, but you can minimize your risk.
If I end up getting it, it will suck, but at the end of the day I will just have to accept that was the genetic hand I was dealt because I can't do anything more than I already do to reduce my risk, realistically, other than move somewhere and be a hermit away from the industrial pollution and environmental toxins that everyone has to deal with these days...
