Honestly man I think all the supplements we take and the entire bodybuilding life style to a degree speeds up cancer especially when you add in hgh steroids and insulin. Truthfully it is just one of those things to where none of us can tell you a straight answer except that we all know steroids and these other products speed up cancer. And that it is your choice if you find it worth taking them. I mean think about it we are increasing the growth in almost all tissue in the body with hgh or steroids so cancer would be no different. And all the influx of extra nutrients and amino acids and over the counter supplements all just add to growth of tissue. I would say honestly do what you want. Just remember that in the end we make our bed and we lay in it.
My dad had cancer and died from it, his mom died from it to, and my dads dad also died from cancer. My moms side is cancer free though. So I know I have a risk but also my dad's family smoked like chimneys and smoked around him as he grew up. So their are other deciding factors we may not be putting into play.