MONDAY, June 22 (HealthDay News) -- An experimental drug therapy appears to have helped destroy allegedly inoperable prostate cancer in two patients in a clinical trial.

Use of the immunotherapeutic agent MDX-010, or ipilimumab, in combination with standard hormone and radiation treatments helped eliminate the aggressive tumors, which had already spread into the patients' abdominal areas, according to a report from Mayo Clinic researchers that appears in Discovery's Edge, the Mayo Clinic's online research magazine. Both patients are now considered cancer-free.

"The tumors had shrunk dramatically," co-investigator Dr. Michael Blute, a Mayo urologist and surgeon who operated on both patients, said in a Mayo Clinic news release. "I had never seen anything like this before. I had a hard time finding the cancer. At one point, the pathologist [who was working during surgery] asked if we were sending him samples from the same patient."

Ipilimumab is an antibody that appears to greatly magnify the cancer-killing action of androgen ablation, a hormone therapy that helps shrink prostate cancer by eliminating testosterone from the body. Following the additional treatment, the patients showed steady decreases in their prostate-specific antigen (PSA) counts, a test used to detect prostate cancer, and were deemed eligible for surgery. After surgery, one patient underwent additional radiation therapy.

"This is one of the Holy Grails of prostate cancer research," clinical trial leader Dr. Eugene Kwon, a Mayo Clinic urologist, said of the antibody therapy in the same news release.

The team plans more research into how ipilimumab works and how to optimize its use.

More information

The American Cancer Society has more about prostate cancer  .

SATURDAY, June 13 (HealthDay News) -- Post-meal surges in blood sugar can cut a man's level of circulating testosterone by about a quarter, new research shows.

The finding might help doctors decide to test for testosterone levels while patients are fasting, the researchers said.

The study, slated for presentation Saturday at The Endocrine Society's annual meeting in Washington, D.C., involved 74 men, including 42 with normal blood sugar, 23 with impaired blood sugar levels ("pre-diabetes") and nine newly diagnosed with type 2 diabetes.

Each of the men drank a sugary solution (75 grams of pure glucose), which typically triggers a spike in blood sugar levels. They then had their testosterone levels tested.

The researchers found that, regardless of whether the men had diabetes or not, blood levels of testosterone dropped by as much as 25 percent after they drank the sugary drink. This trend continued for more than two hours after the glucose was ingested. In fact, 15 percent of the 66 men with normal testosterone levels before the test had low testosterone ("hypogonadism") at some point during the test.

Changes in insulin levels didn't seem to affect the results, nor did levels of other hormones, the team said.

Doctors need accurate testosterone testing to see whether men are hypogonadal and require testosterone supplementation, study co-author Dr. Frances Hayes, an endocrinologist at St. Vincent's University Hospital in Dublin, Ireland, said in a news release from the Endocrine Society. Because testosterone now seems tied to blood-sugar levels, "this research supports the notion that men found to have low testosterone levels should be reevaluated in the fasting state," said Hayes, who did the research while at Massachusetts General Hospital in Boston.

More information

There's more on testosterone at the U.S. National Library of Medicine.

THURSDAY, April 2 (HealthDay News) -- Gene mutations that cause infertility in men could point the way to a male birth control pill, American and Iranian researchers say.

"We have identified CATSPER1 as a gene that is involved in non-syndromic male infertility in humans, a finding which could lead to future infertility therapies that replace the gene or the protein. But, perhaps even more importantly, this finding could have implications for male contraception," co-study author Michael Hildebrand, a postdoctoral researcher in otolaryngology at the University of Iowa, said in a university news release.

He and his colleagues discovered the gene mutations while analyzing the genetics of families in Iran -- where there are relatively high rates of disease-causing gene mutations -- to identify the genetic causes of deafness.

During their study, the researchers identified two families in which male infertility appeared to be inherited. Further investigation revealed that both families had mutations in the CATSPER1 gene. It's believed the mutations affect sperm motility, the motion sperm use to enter an egg during fertilization.

"Identification of targets such as the CATSER1 gene that are involved in the fertility process and are specific for sperm -- potentially minimizing side effects of a drug targeting the protein's function -- provide new targets for a pharmacological male contraceptive," Hildebrand said.

The study appears in the April 2 online edition of the American Journal of Human Genetics.

More information

The American Urological Association Foundation has more about male infertility  .