We all know what Cialis (tadalafil) does for the phallus, but what if it fought cancer? A team from Johns Hopkins University School of Medicine just started enrolling patients in a clinical trial on Cialis for treating head and neck cancer.

The irony, perhaps, is that the tumors Cialis may help treat are more and more likely to be due to oral sex—one thing Cialis certainly makes more likely. A growing number of such cancers appear to be driven by infections with the human papilloma virus (HPV), which appear to be spreading via oral-genital sex, Maura Gillison, an Ohio State cancer researcher said last week at the Damon Runyon Cancer Research Foundation Clinical Investigator Symposium in New York City.

Circumcision is often touted for its potential health benefits: reduced risk of urinary tract infections for baby boys, and lower rates of HIV in teens and men. Now a new study shows that it may also cut a man's chances of contracting two more common, incurable sexually transmitted diseases.

Two randomized, controlled trials in Uganda involving 5,534 men found that those who underwent circumcision as adults were 25 percent less likely to become infected with herpes and more than 30 percent less likely to catch human papillomavirus (HPV) than their uncircumcised peers. (Eight percent of circumcised men and 10 percent of uncircumcised men in the study caught herpes; 18 percent of circumcised men and 28 percent  of uncircumcised men contracted HPV.) The research published today in the New England Journal of Medicine didn't, however, find that getting circumcised reduced the risk of contracting syphilis. Previous research has shown that circumcision reduces a man's risk of acquiring HIV by as much as 60 percent.

The feds want the folks who read Pap smear results that check for cervical cancer to take a more rigorous proficiency exam.

A proposal by the Centers for Medicare & Medicaid Services (CMS) would require pathologists and cytologists taking the proficiency exam to read 20 instead of 10 slides of cells. But it would also allow them to take the exam once every two years instead of annually.

Poor analyses of Pap smears in the late 1980s that led to women dying of cervical cancer prompted Congress to pass the Clinical Laboratory Improvements Amendments of 1988, which requires CMS to establish minimum quality standards for lab testing in the U.S. But the testing requirement for Pap smear readers wasn’t implemented on a nationwide basis until 2005.

With the exception of the so-called cervical cancer vaccine, no shots have been approved specifically to prevent malignant tumors. But cervical cancer, which is caused by the sexually transmitted human papillomavirus (HPV), isn't the only tumor linked to a virus; another is cytomegalovirus (CMV), a usually harmless form of herpes that's the target of a possible therapeutic cancer vaccine for brain tumor patients.

As Scientific American reports this month, CMV has been found in the most common type of brain tumor, glioblastoma multiforme (GBM) — the cancer Massachusetts Democratic Sen. Edward Kennedy is battling. Duke University is recruiting 20 patients with these types of tumors for a combined phase 1/2 clinical trial (an early stage of testing that checks the safety and usefulness of a product) of an experimental vaccine treatment for these patients. It's also testing a similar version in another trial.