Infectious Disease News
Posted August 26, 2011
New vaccine provides ‘strong protection’ for anal cancer, and researchers discover that separate screening for HPV 16/18 may represent a more effective screening strategy.
Results from two recently released studies show that researchers are seeing progress in preventing HPV-related anal cancer and in screening for HPV-related cervical cancer.
Both sets of results were published in a recent issue of The Lancet Oncology.
Maurie Markman, MD, national director of medical oncology at Cancer Treatment Centers of America, said neither study represents a great leap forward, but highlights the importance of HPV as a target for prevention and treatment.
In the first study, Aimée R. Kreimer, PhD, and colleagues recruited 4,210 Costa Rican women aged 18 to 25 years into a randomized, double blind trial to evaluate the ability of the bivalent HPV vaccine Cervarix (GlaxoSmithKline) to protect against persistent type-specific infection with HPV 16, HPV 18 or both, and associated precancerous lesions at the cervix. Enrollment lasted from June 28, 2004, to Dec. 21, 2005.
Participants were assigned to either Cervarix (n=2,103) or to a hepatitis A vaccine as a control (n=2,107). There were 1,989 women in a restricted cohort who were negative for cervical HPV 16 and HPV 18 DNA and negative by serology at baseline. About 71% of women in both groups provided an anal specimen. Median follow-up was roughly 48.8 months in both groups.
In the full cohort, vaccine efficacy against anal HPV 16/18 infection was 62% (95% CI, 47.1-73.1). The corresponding cervical vaccine efficacy was 76.4% (95% CI, 67-83.5).
There were 27 diagnosed HPV 16-related anal cancers in the vaccine group vs. 85 diagnoses in the control group, for a vaccine efficacy of 68.2% (95% CI, 51.4-79.7). For cervical cancer, researchers observed 28 diagnoses in the vaccine group compared with 116 in the control group. Vaccine efficacy against cervical HPV 16 was 75.8% (95% CI, 63.8-84.2).