Lead author Dr Gina Ogilvie said: 'Offering women HPV tests for cervical cancer screening detects more precancerous lesions earlier and also a negative HPV test offers more assurance that women will not develop pre-cancer in the next four years.
Researchers compared the HPV test against Pap smear screenings over the course of four years in a randomized trial of more than 19,000 Canadian women. Pap smear and HPV testing market can be classified into five major segments, namely, monoclonal and polyclonal antibodies, immunoassays, molecular diagnostics, chromosomal analysis, and other analyses.
"Whether it's co-testing or choosing one test over another, it's really important to think about the system in which cervical cancer screening is introduced, and that women are called back and followed-up for an abnormal test, whether it be a Pap smear or an HPV test", Ogilvie said. Those in the Pap group who tested negative returned two years later for another and, if they tested negative again, returned at the end of the four-year study.
The study, published in the Journal of the American Medical Association, adds to a growing body of evidence that HPV tests may be superior to Pap smears. In both the groups, the final co-testing discovered more abnormal cells within some of the women who initially tested negative.
"If you tested everyone for HPV in their 20s, they are nearly all going to be positive, but there's going to be all of this intervention that's not needed", she says. But others disagree, saying that the Pap smear can catch a small number of cases of abnormal cells that might be missed by the HPV test and that co-testing should continue.
The smear tests were carried out using liquid-based cytology (the standard method used in the NHS).
Cervical cancer screening is essential because almost 13,000 women in the US are diagnosed with cervical cancer annually.
Major driving factors for the growth of this market include, increasing prevalence of cervical cancers, increasing demand for advanced cancer diagnostics, increasing awareness about technological advancements in cancer testing and aging population.
Whether they receive a Pap test or an HPV test, the experience for patients is the same in their doctor's or nurse practitioners' office. Women in their 20s are advised to get Pap smears, not HPV tests, because the virus is so common that most would test positive for infections that would most likely clear up on their own. Of the women who tested negative on the HPV test only 22 women showed abnormal cells (grade 3 or worse), while from the Pap smear group, 52 women ended up with abnormal cells. According to the article, the researchers surveyed 5080 women treated for early-stage breast cancer by 377 surgeons in Georgia and Los Angeles between 2013 and 2015.
Of note, the Canadian Task Force on Preventative Health Care differs from the US task force - it recommends Pap smear screening every three years between ages 30 and 69, citing weak evidence for screening women ages 25 to 29. About 4,200 women will die of the disease. They also found that the HPV test was a better predictor of women who would be cancer free in future compared to Pap test. The vaccine is given to teens and young adults, but generations of women are still at risk of cervical cancer because HPV eventually infects most people at some point. This type of cancer is mostly caused by the human papillomavirus (HPV), in as much as 99% of all cases.
'This can mean that women may need to be screened less frequently but have more accurate results.' There are about 3,000 cases of cervical cancer in the United Kingdom every year, leading to around 850 deaths. Partly because of that, he said, "we're a long way away from replacing the Pap smear".