The Arizona Cancer Center is looking for hundreds of male volunteers ages 18 to 44 to participate in its multiyear studies on the human papillomavirus infection.

The ACC is local part of a network of comprehensive cancer-study centers designated by the National Cancer Institute, said Alan Nyitray, who works as a recruiter in two HPV studies.

"The Center has been doing research regarding STDs for many years," Nyitray said. "The current two studies are only the most recent."

The current studies, which are being conducted at the Center's clinic, 2810 N. Alvernon Way, will monitor male volunteers for 18 months to determine how many become infected with HPV, what risk factors are associated with infection, and how quickly they recover.

According to the Centers for Disease Control and Prevention, HPV is a sexually transmitted disease that can lead to penile and anal cancers in men and cervical, vulvar and anal cancers in women.

About 20 million people are living with HPV nationwide, and at least 50 percent of sexually active men and women acquire genital HPV infection at some point in their lives, according to the CDC.

Nyitray said the HPV studies being conducted are important for advancing research in the field.

"The Cancer Center has a strong reputation for excellent research, including research on HPV," Nyitray said. "These studies continue that tradition."

The center began studying HPV because it is a very common STD that causes cervical cancer in women, which is one of the most common cancers in women, Nyitray said.

Nyitray also said HPV can be passed through anal, oral and vaginal intercourse and through skin-to-skin contact, which can also cause genital warts.

"HPV can also cause genital warts in both sexes," Nyitray said. "However, many people who contract HPV have no symptoms of the disease."

The AZCC, which began recruiting for the studies in late 2003, will compensate participants for their part in the study.

"There is monetary compensation," Nyitray said. "But the main compensation is knowing that you've helped bring science one step closer to treatments for HPV that will save many lives."

Carrie Nielson, the study coordinator for the two male HPV studies, said they are still looking for more men to participate.

"We are still looking for several hundred more men to participate," Nielson said. "And we thank the men who have already enrolled and are continuing to participate now."

Nielson said she believes the study will help advance research on HPV and will also help the UA.

"These are some of the first studies in the world to specifically study HPV in men," Nyitray said. "There are many students, staff and faculty of the UA who participate in our studies and get to see first-hand what goes on in medical research studies."

Nielson said the men who participate could benefit women's health as well.

"(The participants) are also helping advance our understanding of the male factors that affect women's risk of cervical cancer, an important worldwide health problem for women," Nielson said.

Although there is no treatment for HPV, many people who are infected clear the infection on their own, Nielson said.

"The reason that some women do not clear the infection but instead develop cancer is not fully understood," Nielson said.

Nielson said there are many other complications involving the diagnosis and treatment of HPV that are not understood as well.

"It's not clear what the best way is to test for HPV in men, which is what one of our studies will determine," Nielson said. "And it's also not understood how long the infection lasts in men and what the antibody response is, which we also hope to find out in our studies."

Nielson said the study is especially important because HPV is common in the Tucson area.

"A previous study done by our group at the Pima County Health Department found that about 30 percent of men had HPV when we tested penile skin swabs," Nielson said.

Overall, Nielson said the studies have provided valuable information on HPV.

"We've had enthusiastic, dedicated participants from UA in our research studies, and they consistently give us positive feedback about their experience in the studies," Nielson said. "We hope to continue our research in HPV in the future by looking at the transmission rates between sexual partners, another issue that will be important for designing prevention strategies."

Nyitray said men who are interested in enrolling in one or both studies should call 318-7178 or 318-7070.