With as many as 50% of young, sexually active women presenting with active Human Papilloma Virus (HPV), understanding the risk for cervical cancer due to persistent infection and the need for adequate screening is crucial. Cervical cancer can be prevented and mortality rates decreased so long as there is early detection and treatment.
It is well established that a higher number of lifetime sexual partners is associated with a greater risk for HPV infection, and therefore a greater risk for HPV-related lesions and cervical cancer. A recent study suggests that another factor, viral reactivation, may be involved in the increased risk for active HPV infection and cervical cancer later in life.
Though the rate of HPV infection in the USA tends to peak in the early 20’s and decline into older age, elsewhere in the world there is a secondary peak around menopause. The study, published in the Journal of Infectious Diseases in 2012, looked at HPV infection rates detected via routine screening in women 35-60 years of age. Of those infected, 77% had a lifetime history of 5 or more sexual partners, but nearly all of the participants reported zero new partners in the previous six months. This does not rule out new HPV exposure as the cause of infection, but it does suggest the possibility that active infections later in life may be due to reactivation of an earlier infection.
Other viruses are known to linger in the body at undetectable levels, only to resurface later and cause new illness. Two such viruses are varicella zoster and Epstein-Barr virus. Varicella zoster, the source of Chickenpox in childhood, can give rise to Shingles later in life. Epstein-Barr can repeatedly recur as Chronic EBV Infection and is even linked to certain cancers.
Might HPV also be lingering and reactivating? It is possible, and warrants further investigation. The current belief is that most young women’s bodies clear themselves of the virus within two years of infection. However, this is based on relatively short term studies that do not look beyond one or two negative screenings. Moreover, there are additional studies which show detection of type-specific HPV after many years of non-detection. It is not yet known whether this is due to re-infection or reactivation, but both must be considered.
Why are these new findings significant? Although HPV infection rates tend to decline with age in the USA, the secondary peak seen in some countries suggests that later infection (or reactivation) poses a very real health risk to middle-aged women world-wide. If the virus is reactivating, American women of the same age group are not immune, regardless of statistical averages. As with varicella zoster and EBV, the health of the individual plays a significant role in whether or not a virus can reactivate. For women with a history of HPV infection, and especially those with signs or symptoms of impaired immune system function, risk of HPV reactivation should be considered and discussed with a healthcare provider.
Below are the 2012 recommendations for HPV and cervical cancer screening, via the US Preventative Services Task Force (USPSTF):
Age/Other Factors Recommendation
<21 years old No screening
21-29 years old Screening pap smear every 3 years
30-65 years old, option 1 Screening pap smear every 3 years*
30-65 years old, option 2 Screening pap smear + HPV test every 5 years
>65 years old No screening if adequately screened before 65
Full hysterectomy No screening unless there is a history of CIN2+
*At least one HPV test after 30 years old is advisable
Dr. Kaley Bourgeois
Gravitt, Patti E., et al. “A Cohort Effect of the Sexual Revolution May Be Masking an Increase in Human Papillomavirus Detection at Menopause in the United States.” J Infect Dis.. 10.1093 (2012).
Infectious Diseases Society of America. “HPV in older women may be due to reactivation of virus, not new infection.” ScienceDaily, 13 Dec. 2012. Web. 19 Jan. 2013.
The American Congress of Obstetricians and Gynecologists. “New Cervical Cancer Screening Recommendations from the U.S. Preventive Services Task Force and the American Cancer Society/American Society for Colposcopy and Cervical Pathology/American Society for Clinical Pathology.” 14 Mar. 2012. Web. 19 Jan. 2013.