Adolescent sexual activity and cancer risk: physicians' duty to inform?

Yearly, 33,000 cancer diagnoses in the US are attributed to human papillomavirus (HPV), with cervical cancer the most common. HPV is transmitted through sexual contact; HPV types 16 and 18 cause the majority of ano-genital cancers in men and women. HPV causes ∼100% of cervical cancers, ∼90% of anal cancers, and ∼50% of vaginal, vulvar, and penile cancers. HPV is also involved in ∼70% of oropharyngeal cancers (OPCs) in the US. The CDC recommends routine administration to all female (bivalent or quadrivalent vaccine) and male (quadrivalent vaccine) patients at 11-12 years of age; the series may be started as early as 9 years of age. Recent evidence suggests physicians do not universally recommend the vaccine to all adolescents. Additionally, parents may refuse the vaccine due to safety concerns as well as religious and moral beliefs related to onset of sexual debut. It has been suggested physicians should consider discussing HPV vaccine as a cancer prevention tool only, with less focus on the fact that transmission is caused by sexual activity. In this commentary we suggest physicians have a duty to warn parents and adolescents that OPCs may be transmitted through oral sex, which is often perceived as not constituting sexual activity.