Targeted human papillomarvirus vaccination: A cost-effective intervention against anal cancer in men who have sex with men

Targeting human papillomavirus (HPV) vaccination at men who have sex with men (MSM) is a cost-effective intervention for the prevention of anal cancer which has a high disease burden in this population and for which there are currently no routine prevention programmes. These are the conclusions of the first cost-effectiveness analysis of HPV vaccination of MSM published Online First in The Lancet Infectious Diseases.

Last year, 2100 men were diagnosed with and 260 died from anal cancer in the USA. HPV types 16 and 18 are known to be responsible for 70% of cases of cervical cancer and also cause 80% of anal cancers. The quadrivalent vaccine targets HPV types 6, 11, 16, and 18 and is used in the routine vaccination of girls against cervical cancer, but it has also demonstrated high efficacy against anal lesions in young MSM. However, the value of vaccinating MSM against HPV is not known. Such a strategy is currently being deliberated by the Advisory Committee on Immunization Practices (ACIP), which advises the US Centers for Disease Control and Prevention (CDC).

In this study, Jane Kim from the Harvard School of Public Health, Boston, USA, uses mathematical modelling to synthesize epidemiological, quality of life, and economic information to predict the cost-effectiveness of HPV vaccination for the prevention of anal cancer and genital warts in MSM in the USA. Model parameters that were varied included vaccination age (12 years, 20 years, and 26 years), previous exposure to vaccine-targeted HPV types, and prevalence of HIV-1.

Interventions that have a cost-effectiveness ratio of less than $50 000 per quality-adjusted life-year gained (QALY)* are generally considered good value for money in the USA. By this criterion, findings showed that targeted HPV vaccination of MSM from 12 years of age up to 26 years of age is economically attractive.

Assuming 50% vaccination coverage and 90% lifelong vaccine efficacy, targeted HPV vaccination of 12-year-old MSM without previous exposure to HPV had a cost-effectiveness ratio of $15 290 per QALY. Therefore vaccination would be very cost-effective in this age group.

Overall, vaccinating MSM mostly remained below the "good value for money" threshold across a range of different scenarios irrespective of age at vaccination and previous exposure to HPV infections. For example, vaccination at 26 years was $37 830 per QALY when previous exposure to all vaccine types was assumed to be 50%. As such, "HPV vaccination of MSM need not occur at the earliest ages to be good value for money."

Kim points out that there are several obstacles to the early uptake of HPV vaccination in MSM including: "Age at which people self-identify as MSM, willingness to disclose sexual identity to others, acceptability of the vaccine, and social stigma of vaccination against a sexually transmitted infection."

She concludes: "Routine vaccination of all men and boys…might not be the best way to prevent anal cancer and genital warts in MSM. Instead, programmes targeting HPV vaccination of MSM at older ages—when more males have established and are willing to disclose their sexual identity—might be a good approach to reach this high-risk group."

In a Comment, Joel Palefsky from the University of California, San Francisco, USA, says that these data: "Suggest that a concerted campaign should be initiated to vaccinate as many eligible MSM aged up to 26 years as possible. There are few or no other routine anal cancer prevention programmes in place, rendering vaccination the best long-term approach for prevention of anal intraepithelial neoplasia and anal cancer."

Dr Jane Kim, Harvard School of Public Health, Boston, USA.
T) +1 617 432 0095 E) jkim@hsph.harvard.edu

Or Todd Datz, Office of Communications, Harvard School of Public Health, Boston, USA. T) +1 617 998 8819 E) tdatz@hsph.harvard.edu

Dr Joel Palefsky, University of California, San Francisco, USA.
T) +1 415 706 5557 E) joel.palefsky@ucsf.edu

*QALY is a measure of disease burden incorporating excess mortality and reduced quality of life associated with a disease.

For full Article and Comment, see: http://press.thelancet.com/tlidanal.pdf

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