I'm far from an expert on MTII but I don't think it will increase your cancer risk much if any unless you mean from the peptide itself. Seems, if anything, it will be more protective in that is causes the body to respond (hyper respond?) to uva and uvb. Also it takes very little time under the sun to get a dark tan and that in itself has to be a bonus when it comes to skin cancer. Darker skin people are far less susceptible to skin cancer than are fair skinned people. Here is an intersesting site that may help. There are of course many others.
Skin Cancer - What Is Skin Cancer? | ehealthMD
I started using it in early April and it took very little time to tan. I spend about and hour and fifteen minutes outside while biking and maybe two hours on the weekend by the pool. Occasionaly longer on other occasions such as when we hiked last weekend. We were out for almost 5 hours and my son (fair skinned) burned on his neck and a little on his face. I went without a shirt and had no problems at all. I now only take a weekly maintenance dose and it seems to be holding my tan steady. I did notice at first my tan was as red (think Native American) as it was brown but that must have just been a phase since I am now brown.
Hope this helps.