This article was last reviewed on
This article waslast modified on 10 July 2017.
Cervical cancer is the second most common cancer in women, each year affecting nearly 500,000 women worldwide and killing almost 300,000. Most cases of both cervical cancer and of the precursor of cancer, cervical intraepithelial neoplasia (CIN), are associated with infection with strains of human papilloma virus (HPV), a virus that can also cause warts. Two kinds of test are used to screen for cervical cancer and CIN: cervical smears and HPV tests. The use of liquid cervical cytology smears - a screening test that requires examining patient samples under a microscope - has reduced mortality rates 50-70% in Europe, the US and Canada, but developing countries lack the appropriate infrastructure and resources to use this method or the newer, more accurate methods that detect the DNA of HPV.

A new modification of the DNA test called careHPV detects 14 types of HPV that can cause cervical cancer. This test has been developed mindful of the need for screening in developing countries. The test does not require highly trained people, mains electricity or running water and needs little bench-top workspace. It produces results within three hours so that women can be tested and treated the same day. The test was developed through collaboration between a diagnostics company and an international non-profit organization dedicated to public health, with funding from the Bill and Melinda Gates Foundation.

A study published in Lancet Oncology in October 2008 compared this new test with other screening tests. A team of researchers from China, the US, Canada and the UK enrolled more than 2,500 women ages 30 to 54 living in rural villages in Shanxi Province, China. Using vaginal brush and cervical swab specimens collected both by patients and by nurse-midwives, the researchers compared careHPV's performance with visual inspection of the cervix using acetic acid (vinegar acid), with an established DNA test commonly used in developed countries and with liquid-based cytology.

Among 2388 women with complete data, 70 - almost 3% - had a precursor of cervical cancer (moderate or severe CIN) but only one had invasive cancer. The careHPV correctly detected these changes in cervical cells 90% of the time and correctly excluded samples without abnormal changes 84.2% of the time. On vaginal samples, careHPV correctly detected these changes 81.4% of the time and excluded samples without such changes 82.4% of the time. For liquid cytology on cervical samples, these figures were 85.3% and 97.0%. The DNA test commonly used in developed countries correctly detected these changes 97.1% of the time and correctly excluded them 85.6% of the time on cervical samples. As expected, all these tests were more sensitive than visual inspection of the cervix with acetic acid.

The researchers write: “Overall, careHPV seems to have performance characteristics that merit further study and, subject to local cost-effectiveness assessments, might be appropriate for use in resource-constrained screening programmes”.

In an accompanying commentary, Dr Luisa Villa writes: “Despite some loss of clinical sensitivity, (careHPV’s) performance in self-sampled specimens could increase screening acceptability in various settings… The ability to obtain accurate results in a few hours is especially important in settings where women are screened only occasionally, allowing for treatment of high-grade (CIN) lesions at the same visit… However, more studies are needed to show the test’s reproducibility and clinical performance in the context of populations with different prevalences of HPV and HPV-related disease.”

The International Agency for Research on Cancer of the World Health Organization (WHO) now recommends that HPV-DNA testing can be used for primary screening. A new WHO program, LabNet, is establishing a global HPV laboratory network that adheres to standard materials and quality practices. LabNet will help ensure the best HPV test performance in different settings.