I had prostrate/bladder cancer they removed both. They say it is of indeterminate origin. I think it's agent orange related. Who knows?

Stop asking.. It's been answered. Now you've added new info. If he was exposed to agent orange back in the war, he'd be getting a check every month like my father in law does.

Answer: nobody knows. There is some evidence that veterans exposed to Agent Orange suffer from elevated rates of aggressive prostate cancer, but nobody can look at an individual case and say what the cause was or even whether there is a cause beyond bad luck.

Get a second opinion from someone qualified to give one instead of random strangers without medical degrees online.

Not me.