Although men and women are similar in many ways, there are important biological differences between the genders. These differences affect the manifestation of diseases and their subsequent treatment.
Cancer generally affects different parts of the body in men and women, but the same vaccine that cuts the risk of cervical cancer in women might also lower the chances of head and neck cancers in men, new research suggests.
In addition to being linked to cervical cancer, the human papillomavirus (HPV) can cause cancers in the back of the throat, in an area known as the oropharynx. HPV is linked with about 70% of these types of cancers in the United States, and the rates of these cancers are rising dramatically, according to the US Centers for Disease Control and Prevention.
The US Food and Drug Administration has approved HPV vaccines for prevention of cervical, vulvar, vaginal and anal cancers in women, and anal cancers in men. However, the HPV vaccine hasn't been FDA-approved for prevention of head and neck cancers, because the vaccines have not been evaluated in clinical trials for that purpose.
According to the Public Health Association of South Africa (PHASA) the Medicines Control Council (MCC) of South Africa approved two HPV vaccines, but these vaccines are only effective when used as a prophylaxis when administered before exposure.
"We don't know if there's a potential solution to these rising rates already existing on [drug] shelves," explained study author Dr Maura Gillison. She is a professor of thoracic/head and neck medical oncology at the University of Texas MD Anderson Cancer Center.
"In the absence of that gold-standard clinical trial, we looked at data from a study that we've been conducting in my lab to address the question as to whether or not existing HPV vaccines could be altering oral HPV infections in the US population," she explained in a Cancer Center news release.
No infections in vaccinated men
The analysis of data from more than 2 600 Americans, aged 18 to 33, revealed that those who had received HPV vaccination were 88% less likely to have oral HPV infections than those who were not vaccinated.
Previous research has shown that HPV-related head and neck cancers are more common in men than women, so Gillison and her colleagues examined whether vaccination was associated with a reduced prevalence of oral HPV infection in men.
"When we compared the prevalence in vaccinated men to non-vaccinated men, we didn't detect any infections in vaccinated men. The data suggests that the vaccine may be reducing the prevalence of those infections by as high as 100%," Gillison said.
"We also wanted to determine, accounting for the low rates of vaccination, what proportion of infections could have been prevented," she said.