As jayadub mentioned, I think the treatment would be more an influence than the fact that you had PC. This was a question that I had for my Hematologist as the rare form of PC that I had (Removed last week by surgery) was found in a post chemo CT scan. I have CLL (Chronic Lymphocytic Leukemia), which is currently in remission and my Hematologist said that about 5% of people with this type of Leukemia develop a second cancer. What I would really like to know is if the chemo was the culprit or if they are completely unrelated.
Stick with the regular check-ups. I never would have known that I had PC had it not been for the post chemo scan as my PSA was normal because I did not have adenocarcinoma but a rare pure neuroendocrine carcinoid on the prostrate.