Second study: bivalent HPV16 /18 vaccine protects against anal HPV infection, especially in HPV-naive
THURSDAY, Aug. 25 (HealthDay News) -- Human papillomavirus (HPV) testing for HPV16 and HPV18 strains may be an alternative and more efficient screening method for cervical cancer than liquid-based cytology alone; and bivalent HPV16 and 18 vaccine protects against anal HPV infection, according to two studies published online Aug. 22 in The Lancet Oncology.
Philip E. Castle, Ph.D., from the American Society for Clinical Pathology Institute in Washington, D.C., compared screening performance of the cobas HPV test (HPV 16 and HPV 18) with liquid-based cytology among 40,901 women aged 25 years or older, and assessed management strategies for women with positive HPV. Histologically confirmed cervical intraepithelial neoplasia grade 3 (CIN3) or worse was the primary end point. In women who had colposcopy, cobas HPV had higher sensitivity than liquid-based cytology for detecting CIN3 or worse. Compared to HPV testing alone, the addition of liquid-based cytology to HPV testing increased sensitivity for detection of CIN3 or worse to 96.7 percent, but increased the number of screen positives by 35.2 percent.
Aimée R. Kreimer, Ph.D., from the National Cancer Institute, National Institutes of Health, in Bethesda, Md., and colleagues investigated the efficacy of AS04-adjuvanted HPV 16 and 18 vaccine against anal HPV infection among 4,210 women who participated in the Costa Rica HPV Vaccine Trial for cervical cancer. Participants randomly received an HPV vaccine or a control hepatitis A vaccine. Prevalence of anal HPV 16/18 infections was assessed at four years. Efficacy of vaccine was lower for anal than cervical HPV 16/18 infection (62 versus 76.4 percent, respectively) in the full cohort, and similar in the restricted cohort tested for anal efficacy only.
"Our findings suggest that the bivalent HPV vaccine protects against a proportion of anal HPV 16 and HPV 18 infections," Kreimer and colleagues write.
Several of the first study's authors disclosed financial ties with industries providing laboratory products and tests, including Roche Molecular Systems, which funded the study. Two of the second study's authors disclosed financial ties with the GlaxoSmithKline Biologicals group of companies, which provided the vaccine for the study.
Abstract Castle
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Abstract Kreimer
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