Eating out: care needed

Seems we need to take care when going down, because the frequency of oral sex might increase the risk of human papillomavirus, HPV, and throat cancer.

HPV is a common sexually transmitted virus that is strongly associated with risk of developing various types of cancer, including cervical cancer. Symptoms of HPV include genital warts, pain during sex and unusual bleeding after sex.


Key research points

  • An individual’s risk of throat cancer caused by HPV is 4.3 times higher with >10 oral sex partners
  • Risk is 2.8 times higher if the individual has multiple sex partners in short time frame
  • Risk is 1.8 higher when first instance of oral sex was before 18 years old
  • Risk is 1.6 times higher when engaging in oral sex with a participant who has had multiple partners

A team led by Virginia Drake of Johns Hopkins University, US, has found that people who’ve had more than 10 previous oral sex partners in their life have a 4.3 times greater risk of developing HPV that leads to cancer of the oropharynx – the middle part of the throat.

The research suggests that there are complex choices when deciding to eat out, and considerations of with whom and how often are just part of it.

This risk is also 1.8 times greater when the participant is under 18 the first time they have oral sex, and 2.8 times higher when the number of oral sex partners occurs within a smaller time frame of five years, the team report in their paper, published in the journal CANCER.

“Our study builds on previous research to demonstrate that it is not only the number of oral sexual partners, but also other factors not previously appreciated that contribute to the risk of exposure to HPV orally and subsequent HPV-related oropharyngeal cancer,” says Drake.

Other increased risk factors that relate to these more representative sex histories were extra-marital sex or engaging with a partner who was suspected of extra-marital sex (1.6 and 3.4 times greater respectively), and engaging in oral sex with an older partner when young (1.7).

The researchers surveyed a group of 508 HPV-positive individuals, 163 of whom had oropharyngeal cancer, to assess whether relationship dynamics played a role in developing cancer from HPV. While oral sex has previously been established to increase risk of HPV, there has been little research into the sexual history participants beyond “yes/no”.

To better understand these subtleties, the researchers adjusted the group against frequency of smoking and then assessed untested sexual history factors. For example, they devised a measure of sexual intensity to estimate the number of partners over a given time frame.

“Similar to how pack-years describes tobacco history and drink-years characterises alcohol use, the new metric of sex-years characterises cumulative sexual exposure over time as a surrogate for potential exposure to HPV,” they write in their paper.

The majority of participants identified as heterosexual males, and were predominantly Caucasian, so the study isn’t a complete overview of everyone’s sexual activity and risk. Future studies on other demographics, including individuals who identify as female and/or homosexuals, as well as more diverse racial representation, could clarify some of the minute differences in HPV-related cancer risk associated with oral sex.


Snapshot: human papillomavirus (HPV)

  • HPV is a common sexually transmitted virus that can lead to cancer
  • Known HPV-related cancers include those of cervix, vagina, penis and anus
  • Anyone who is sexually active and unvaccinated is at risk of HPV
  • Preventatives include vaccinations, condoms, and abstinence

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