One other thing is wrong with this -- the penile cancer thing is related to HPV, and now boys (in addition to girls) in US are going to be 100% inoculated. So that argument goes away. Also, the incidence of penile cancer is extremely low (less than 1 in 100k men, which is less than 1% of all cancer incidence) whereas the risk of complications from circumcision are significant, so it isn't the type of disease that society generally would even bother to address. Lastly, men that do get penile cancer usually get it extremely late in life (like 70+ years old) and so it isn't really as big a deal to lose sexual function at that age.

I've listened to the same sisters, and another complaint I have with them is simple bad science -- they claim that the women that undergo circumcision experience sex the same and don't miss anything. However, you can't ask someone who has never had something whether they are missing it! It may be that circumcised women can still orgasm, but to really do science on it you'd need to have a decent sample of women both with and without the clitoris, all from similar culture and health, and even then it would be difficult to make a claim. I think it is just common sense that if you lose a part of your body that you lose something, and since the clitoris is known to be fairly involved in the sexual response of women who are not circumcised it is hard to believe a claim that they haven't lost something -- or at least you need some really good science to prove that claim.

Oh, and regarding circumcision in general (male or female) there is a simple way to prove if it is right for a parent to alter a child's body cosmetically: just imagine if a parent wanted to tattoo their baby. In adults, tattoos are actually as common, or more, than male circumcision so what's the problem with a parent wanting their kid to fit in? It's pretty obviously wrong. Anyway, I think that's the simplest way to show how ridiculous any argument about a parent having the right to circumcise is. A parent simply doesn't have the right to alter a child's for cosmetic reasons. Anyone who wants to be circumcised can do it as an adult, just like getting a tattoo.