Comments

"[Spermatogonial progenitor stem cells] neatly sidestep the ethical dilemmas that have hamstrung stem cell research over the past few years." Maybe it's just my imagination, but it seems like every few months we hear about a new, non-embryonic stem cell source (blastomeres, amniotic stem cells, etc...). Has anything useful come from these other "ethical" stem cells?

Hello StartledGnu. It's possible that I'm overlooking something, but I see no possible way that a double blind circumcision trial could even be conducted. I mean, when you remove the prepuce from a man's penis, he's bound to notice. While a fully controlled experiment is always the gold standard, sometimes it simply isn't possible. In this case, the authors did a very good job of controlling for as many confounding factors as possible. As you indicate, the RCTs were stopped early. However, the studies were not terminated by the authors, but by their ethical boards. This, as I'm sure you are aware, was done because the protective effect of circumcision against penile HIV acquisition was so great that it was considered irresponsible to let the control group (uncircumcised men) remain at risk. Concerns about early RCT termination and how they affect data interpretation provide a careful, and much needed, voice of moderation to the circumcision/HIV dialogue. However, it should be noted that a recent meta-analysis of the three African RCTs (11,050 total participants) found that circumcision IS an effective intervention against HIV transmission [Mills et al. 2008. Male circumcision for the prevention of heterosexually acquired HIV infection: a meta-analysis of randomized trials involving 11050 men. HIV Medicine 9(6):332-335]. All of this is besides the point though, because such concerns about early study termination have not been advanced in regard to the new Krieger et al. results. A 1.5% complication rate is actually a bit on the low side for a surgical procedure (whether or not circumcision is "highly invasive" is debatable), and while some serious problems inevitably occurred, almost all of them were minor hemorrhage or infections. Whether or not the foreskin confers a fitness advantage for modern man is an interesting topic to consider. Obviously, evolution made the prepuce what it is today, but its role in human male reproduction is difficult to fully ascertain. It doesn't seem to have a significant effect on reproductive success in modern man. Finally, the WHO notes that unlike male circumcision, female circumcision has "no health benefits for girls and women." [WHO Fact Sheet on female genital mutilation] The ethics of removing healthy genital tissue must be based on a harm versus benefit analysis. It seems clear to me that the ratio of harm to benefit is MUCH HIGHER for female circumcision than male circumcision. Therefore, while there are some very general anatomical similarities between the two procedures (the male prepuce being analogous to the female clitoral hood), it is problematic to analogize the two.