Oral Sex Linked To Throat Cancer

Recent research indicates that human papillomavirus (HPV) transmitted through oral sex can cause many oral cancers.1-3 There has been a serious upsurge in the incidence of oral cancers in the United States. Oral cancer cases have risen rapidly in the US from 1975 to 2007, predominantly in young white males.4 HPV is thought to be a strong risk factor contributing to this alarming statistic and risky sexual behavior is a strong predictor of sexually transmitted infections (STIs) such as HPV infection. This risk of oral cancers increases with the number of oral sex partners.1,2

Oral sex is common among adolescents. It is estimated that one in five adolescents have had oral sex by the end of the ninth grade.5 Among youth between the ages of 15 and 19 years, more than half have had oral sex with members of the opposite sex and this increases to more than 80% in college-age youth.6 Teens may not fully understand the attendant and real risks associated with the practice of oral sex.5,7

Oral sex has become more common among teens because of the erroneous perception that oral sex is harmless since it does not result in pregnancy. There is, however, evidence that oral sex is becoming the gateway to penile-vaginal sex. One study found that adolescents who initiate oral sex by the end of 9th grade had a 50% chance of initiating vaginal sex by the end of 11th grade.8

Adolescents often fail to weigh the consequences of engaging in sexual behaviors that they consider less risky. Oral sex is sex — and it carries many of the same risks as vaginal sex, including acquisition of infections such as HPV. HPV is a ubiquitous STI in humans. There are over 120 different types of HPV; about 40 of these are sexually transmitted and affect the mouth and genital areas in human beings. It is estimated that 20 million people are currently infected with HPV; 6 million Americans become newly infected each year and at least 50% of sexually active persons will acquire an HPV infection at some point in their lives.

HPV infections are often asymptomatic and about 90% resolve within 2 years.10 However, persistent infections may result in complications such as oral and genital cancers. Infections with some types of HPV can have more serious consequences than others. One of the HPV subtypes, HPV 16, is responsible for about 60% of cancers of the tonsils and throat in the US. HPV 16 has been detected in about a quarter of all head and neck cancers.11 It has been estimated that any HPV exposure increases the risk of head and neck cancer 33-fold; oral HPV 16 infection alone accounts for a 15-fold increase in the risk of oral cancer. HPV 16 subtype has been found to be directly responsible for 90-95% of HPV-related oral cancers.1,3 This risk from HPV infection outweighs the risk of cancer associated with heavy alcohol and tobacco abuse.1 Other HPV associated cancers include anal, cervical, vaginal and penile cancers.9

In conclusion, recent research confirms that oral sex is risky sexual behavior and increases the likelihood of HPV-related cancers. This evidence underscores the importance of educating our youth of the need to avoid all risky sexual activities, including oral sex, in order to avert long term harmful consequences. Waiting until they are in a committed lifelong relationship with an uninfected partner maximizes the prospect that youth will enjoy healthy, happy and hopeful futures.

References:

1. D’Souza G, Kreimer AR, Viscidi R, et al. Case-control study of human papillomavirus and oropharyngeal cancer. N Engl J Med. 2007;356:1944–1956.

2. Gillison M, D’Souza G, Westra W, et al. Distinct risk factor profiles for human papillomavirus type 16–positive and human papillomavirus type 16–negative head and neck cancers. J Natl Cancer Inst. 2008;100:407–420.

3. Kreimer AR, Clifford GM, Boyle P, Franceschi S. Human papillomavirus types in head and neck squamous cell carcinomas worldwide: a systematic review. Cancer Epidemiol Biomarkers Prev. 2005;14:467–475.

4. Altekruse SF, Kosary CL, Krapcho M, et al. SEER Cancer Statistics Review, 1975-2007, National Cancer Institute. Bethesda, MD. Available at: http://seer.cancer.gov/csr/1975_2007/. Accessed March 15, 2011.

5. Halpern-Felsher BL, Cornell JL, Kropp RY, Tschann JM. Oral versus vaginal sex among adolescents: perceptions, attitudes, and behavior. Pediatrics. 2005;115(4):845-851.

6. Mosher WD, Chandra A, Jones J. Sexual behavior and selected health measures: men and women 15-44 years of age, United States, 2002. Adv Data. 2005;362(362):1-55.

7. Brady SS, Halpern-Felsher BL. Adolescents’ reported consequences of having oral sex versus vaginal sex. Pediatrics 2007;119:229-236.

8. Song AV, Halpern-Felsher BL. Predictive relationship between adolescent oral and vaginal sex. Arch Pediatr Adolesc Med. 2011;165(3):243-249.

9. CDC, Genital HPV infection, CDC Fact Sheet, November 2009, Available at: http://www.cdc.gov/std/HPV/STDFact-HPV.htm. Accessed March 15, 2011.

10. Moscicki AB, Schiffman M., Kjaer S, Villa LL. Chapter 5: Updating the natural history of HPV and anogenital cancer. Vaccine. 2006;24(3): S42-51.

11. Fahkry C, Westra WH, Li S, et al. Improved survival of patients with human papillomavirus-positive head and neck squamous cell carcinoma in a prospective clinical trial. J Natl Cancer Inst. 2008;100:261–269.

Reviewed: March 2011