Janis C. Kelly
February 17, 2010 — Findings from a natural-history study of human papillomavirus (HPV) have led the investigators to conclude that the “potential benefit” of HPV vaccination in older women (≥42 years) is “low.”
The research team, led by Ana Cecilia Rodríguez, MD, from the Proyecto Epidemiológico Guanacaste, Fundación INCIENSA, in San José, Costa Rica, found that the rate of new HPV infections declines with age and that new infections usually do not progress to grade 2 or 3 cervical intraepithelial neoplasia (CIN) in older women.
The investigators found that infections at baseline were more likely to persist in older than in younger women (P < .01 for a comparison of 8 groups). Furthermore, most of the grade 2 or worse CIN disease that was detected during follow-up (66 of 85 cases) was associated with infections already present at baseline.
The 7-year study of Costa Rican women — the largest ever to examine age, HPV persistence, and cervical cancer precursors — was published online February 15 in the Journal of the National Cancer Institute.
“This is a great paper, the longest follow-up study to date available on women in a broad age range,” said Silvia Franceschi, MD, who was approached by Medscape Oncology for independent comment.
Dr. Franceschi, who is coordinator of the epidemiology and biology cluster at the International Agency for Research on Cancer in Lyon, France, noted that there seems to be very little to gain by vaccinating women older than 25 years or so.
“The ‘dangerous’ or persistent infections may be already there and will not be eliminated by the current HPV vaccines,” she added. “The pharmaceutical industry’s claim that vaccine should be given to older women because HPV infections are more dangerous after a certain age has been proven not to be true.”
More Than 9000 Women, 7-Year Follow-Up in HPV Study
The researchers screened more than 9000 women, 18 to 97 years, in Costa Rica. Those with CIN 2 disease or worse at enrollment were treated and not followed any further. Among the remaining participants, those at low risk for CIN 2 or worse were rescreened at 5 to 7 years (passively followed), whereas higher-risk participants and subsets of low-risk women and initially sexually nonactive women were rescreened annually or semiannually (actively followed) for up to 7 years.