Although alcohol abuse and smoking are still the main causes of oropharyngeal carcinoma, human papillomaviruses have been increasingly detected in lesions in recent years. A recent study demonstrated the association between HPV status and pharyngeal cancer risk in people after active oral sex.
Oral sex has long been considered a low-risk sexual practice, especially among younger people. However, far from it - the mucous membrane of the mouth with its moist and warm environment offers a similarly good entry point for sexually transmitted infections (STI) as, for example, the genital or anal mucosa. Besides treponema pallidum, herpes viruses and gonococci, human papillomaviruses also find infectable cells in the oral mucosa.
A study from the USA now showed that HPV infection in the oral cavity can increase the lifetime risk of oropharyngeal tumours in people who have frequent oral sex. In this case-control study, patients with head and neck tumours filled out questionnaires that asked, among other things, about their sexual behaviour.
The study included 163 patients with head and neck tumours and 345 controls. The results showed that the number of oral sex partners in a lifetime has a particular influence on the risk of developing oropharyngeal carcinoma.
With more than 10 partners, the risk of HPV-associated oropharyngeal carcinoma increased 4.3-fold (OR = 4.3; 95% CI: 2.8-6.7). If the number of sexual partners and smoking were excluded as risk factors for cervical head tumours, two further significant risk factors remained: First, a young age of onset, and second, a high annual oral sex frequency.
While the risk (odds ratio; OR) is greater by a factor of 4.4 for people who have ever had oral sex in their lives, those who had their first oral sex at an age < 18 years are already about 1.8 times more at risk of developing oropharyngeal carcinoma later in life.
HPV-16 in particular appears to be associated with oropharyngeal carcinoma. A positive result for the E6 protein of HPV-16 or any other E protein of the virus was associated with a higher lifetime risk.
This recent study once again demonstrates the importance of including sexual history in cancer screening. People who were sexually active at a very early age as adolescents and who have also frequently changed sex partners are at higher risk for HPV infections and thus also for a number of tumour diseases caused by HPV. In addition to oropharyngeal carcinoma, these can include cervical cancer, penile carcinoma or anal cancer.
In daily practice, it is also important to note that teenagers and adolescents who have not yet had contact with HPV may benefit from the nonavalent HPV vaccination recommended for both sexes from the age of 9 years. This prevents infection with some of the tumour-associated viruses, including HPV-16 and HPV-18, and reduces the risk of genital warts, which are primarily caused by HPV-6 and HPV-11.