That's an interesting conjecture, isn't it?  There have been no studies done on that particular question.  Anecdotally, I have a fairly large group of patients between 40-70 (skin cancer age) who have been using the product for approximately 5 years, and we've not observed any increase in skin cancers. 

The current thinking is, since skin cancers occur in an environment of unhealthy cells damaged by sun/UV light,  that as the cells gets healthier with protection from sun/UV light, use of retinoids (vitamin A creams), and antioxidants (also protective), fewer skin cancers will occur. 

It's possible that if the serum growth factors (like TNS) promote the growth of healthy cells that it reduces skin cancers. There just isn't any science relating to skin cancers and grown factors that I have seen.  Dr. I