A human papillomavirus 16/18 vaccine along with cytologic screening could reduce the absolute lifetime risk of cervical cancer by 94%, according to a recent study.
Because such a vaccine may be commercially available in a few years, researchers sought to determine the most beneficial and cost-effective strategy for its use. They found that the most effective method of implementation with an incremental cost-effectiveness ratio of less than $60,000 per quality-adjusted life year is one that follows vaccination of adolescent women at age 12 with triennial conventional cytologic screening beginning at age 25. The next best strategy is vaccination and cytologic screening every 5 years beginning at age 21.
In terms of the vaccine, results from a Phase II trial indicate 100% efficacy over an 18-month period in preventing persistent HPV 16 infection and HPV 16-specific cervical intraepithelial neoplasia. Larger Phase III trials of vaccines targeting different HPV types are under way.
While a vaccine is not yet available, the Food and Drug Administration recently approved HPV DNA testing for adjunctive use with cervical cytology in women aged 30 years or older. The question is whether HPV DNA testing in conjunction with cervical cytology for primary screening of these women provides any greater benefit, when compared to HPV DNA testing for only women with equivocal cytologic results.
Researchers from Harvard and Columbia Universities found that for women aged 30 and older, any biennial or triennial screening strategy that uses either HPV DNA testing in combination with cytology for primary screening or cytology with reflex HPV DNA testing for women with equivocal results provides greater reduction in cancer incidence and at a lower cost than annual conventional cytologic screening alone.
Estimated reduction in lifetime risk of cervical cancer varied from 81% to 93% depending on the screening frequency, type of cytology, and test strategy used. Cost-effectiveness ratios ranged from $95,300 to $228,700 per year of life gained.
Strategies that provided minimal additional benefit but that greatly increased costs included primary screening with cytology and HPV DNA testing in women younger than age 30 and annual screening with combined HPV DNA testing and cytology. The latter provided only a few hours of additional life expectancy and had a cost-effectiveness ratio of more than $2 million per life-year gained.
Goldie SJ, Kohli M, Grima D, et al. Projected clinical benefits and cost-effectiveness of a human papillomavirus 16/18 vaccine. J Natl Cancer Inst. 2004;96:604-615.
Goldie SJ, Kim JJ, Wright TC. Cost-effectiveness of human papillomavirus DNA testing for cervical cancer screening in women aged 30 years or more. Obstet Gynecol. 2004;103:619-631.