You
need not put an end to your source of sexual enjoyment.
While
excessive testosterone has a positive relationship with
the growth of a prostate cancer, it’s doubtful if it
actually CAUSES the cancer. Masturbation or other sexual
activity does not lead to the come back of cancer. On
the other hand, these sexual activities are reported to
have beneficial and preventive effects on
prostate cancer.
Also see
the following links from respectable sources:
http://www.newscientist.com/article.ns?id=dn3942
http://urology.jhu.edu/newsletter/prostate_cancer712.php