I generally agree with you regarding infant circumcision, and the fact that the HIV research was critically flawed. Some emerging evidence is coming out of Australia, however, that suggests circ may reduce risk of prostate cancer (I'll find a link if I can). Still, it is a reduced risk, not an outright negation of risk. Then again, stapling your mouth shut reduces your risk of obesity ...
I would add that some research also showed similar "results" in the USA, however, it could be that Jews, who are routinely circumcised, have different epidemiological reasons for lower incidences of prostate cancer, e.g. genetic, diet, life style.
I have not seen anything that makes a direct causal connection between circumcision and prostate cancer.
What is Prostate Cancer? - WebMD
"On a case-by-case basis, doctors cannot say with certainty what causes prostate cancer, but experts generally agree that diet contributes to the risk. Men who consume large amounts of fat -- particularly from red meat and other sources of animal fat -- are most likely to develop advanced prostate cancer. The disease is much more common in countries where meat and dairy products are dietary staples than in countries where the basic diet consists of rice, soybean products, and vegetables...
...Researchers know more about what will not cause prostate cancer than what will. No proven link exists between prostate cancer and an active sex life, vasectomy, masturbation, use of alcohol or tobacco, circumcision, infertility, infection of the prostate, or a common noncancerous condition called benign prostatic hyperplasia (BPH) that causes an enlarged prostate gland. Most elderly men experience an enlarged prostate to some degree."
Likewise the HIV studies are probably more to do with general lifestyle and cleanliness.
Circumcision is an assault.
(and no I am not, despite the efforts of the doctor who delivered me).
A