Using visual inspection with acetic acid (VIA) coverage targeted at women aged between 30 and 45 years at five-year intervals is an effective and cost-effective approach to reduce the burden of cervical cancer in the Philippines. These are the results of a recent study published in the journal BMC Public Health entitled “A cost-utility analysis of cervical cancer screening and human papillomavirus vaccination in the Philippines”.
Cervical cancer is the second most common female cancer in the Philippines with about 6,670 women diagnosed in 2010. Cervical cancer has an annual age-standardized incidence rate of 11.7 per 100,000 women.
The five-year survival rate did not improve from 1980 to 2010 because of late-stage diagnosis as a result of the lack of screening and inadequate treatment services. Pap smear was introduced in the Philippines in the 1990’s for women aged between 35 and 55 years, and was performed only once over the life of the patient. In 2005, the policy changed to the single visit approach using visual inspection with acetic acid (VIA) followed by cryotherapy. VIA was found to be more useful than Pap smear which had a very low uptake rate of only 7.7 %. The current national recommendation is to target women aged between 25 and 55 years with VIA done in five to seven year intervals.
The Philippine FDA has two registered vaccines, the bivalent vaccine (Cervarix®) and a quadrivalent vaccine (Gardasil®), both protecting against high-risk oncogenic types HPV 16 and 18.
To evaluate the health and economic benefits of HPV vaccination and its combination with different screening strategies for an optimal preventive strategy in the Philippines the research team led by Anna M. Guerrero from the Department of Health Philippines, Pharmaceutical Division, conducted a cost-utility analysis to investigate different screening and vaccination strategies against HPV infection implemented alone or as part of a combination strategy in different coverage scenarios.
Results revealed that through all coverage scenarios, VIA is a cost-saving and dominant screening strategy with an increased cost-effectiveness ratio (ICER) ranging from dominant to Php 61,059 ($1,443) per quality-adjusted life year (QALY) gained. Results also showed that VIA reduces by 25% the cases of cervical cancer. Furthermore, the study demonstrated that Pap smear screening was not cost-effective in the Philippines as a consequence of its high cost.
Adding the HPV vaccine at a cost of $54 per vaccination on top of VIA screening was found to be cost-effective using a threshold of 1 GDP per capita (i.e., Php 120,000 or $2,835 / QALY). The assumption is the provision of lifelong immunity against high-risk oncogenic HPV types 16/18.
The researchers also determined that the highest incremental QALY gain was attained with 80% coverage of the combined strategy of VIA screening in women aged between 35 and 45 years done every five years after vaccination at 11 years of age with an incremental cost-effectiveness ratio (ICER) of Php 33,126 ($783).
According to the researchers, this strategy may result in a two-third reduction of cervical cancer burden. Importantly, this study demonstrated that HPV vaccination is not cost-effective when vaccine protection lasts for less than 20 years.