A new strategy for cervical cancer prevention
No woman should die from cervical cancer, a preventable disease. Yet it is still responsible for approximately 265,000 deaths each year.1 Advanced screening and diagnostic tests are key to improving disease prevention strategies.
What is cervical cancer?
Cervical cancer is one of the most preventable cancers today thanks to vaccination, screening and early treatment. Nonetheless, it remains one of the most common and deadliest cancers in women worldwide. Approximately 530,000 women are diagnosed with cervical cancer each year.1
Almost all cervical cancers – more than 99% – are caused by a persistent high-risk human papillomavirus (HPV) infection.2 Finding and treating pre-cancerous disease early, before cancer develops, is an important prevention strategy.3
The Pap test - a well established screening tool with limitations
The Papanicolaou test (also known as Pap smear or Pap test), was invented in the 1940s by Dr. George Papanicolaou, and for decades it was the only test for early detection of cervical cancer. Where it has been utilised, the Pap test has helped reduce the number of women affected by or who die from cervical cancer by at least 80% in the last 70 years. But it has limitations due, in part, to the subjective interpretation of the test.4
In Pap tests, a healthcare professional uses special tools to scrape cells from the surface of the cervix. The cells are then sent to a laboratory for cytological analysis where a trained cytotechnician looks for abnormalities under a microscope. Abnormal cells can be difficult to differentiate from normal cells and can be missed. One third of cervical cancers occur in women who have had normal Pap test results.5-7
Screening for HPV - a new strategy for cervical cancer prevention
During the 1980s, a link between HPV infection and cervical cancer was identified, and in 1996 the World Health Organization publically recognised that HPV is the most important risk factor in the development of cervical cancer.
HPV is a common virus; approximately 80% of women (and men) will have had an HPV infection by age 50.8 The vast majority of HPV infections are transient and are taken care of by the immune system without a long-term impact on health. However, in some women the infection becomes persistent and may lead to cervical disease and eventually cancer if untreated.3
There are more than 100 types of HPV. Some types carry more risk than others, and at least 13 HPV types are considered high-risk for cervical cancer. In fact, 70% of cervical cancer cases are caused by two specific genotypes—HPV 16 and 18.3
Doctors can now screen women for the presence of HPV using advanced HPV testing that looks for the specific high-risk HPV genotypes most likely to cause cervical cancer. The high-risk HPV test can be used for primary screening.9,10
In an analysis of more than 60,000 women, high-risk HPV testing was substantially more sensitive in detecting cervical disease than Pap tests (96.1% vs. 53.0%), a finding later confirmed by a study that included more than 47,000 women.11-13
While there is no cure for an HPV infection, it is possible to stop disease progression and treat pre-cancer or cancer. A woman positive for high-risk HPV will need to be managed according to recommended clinical guidelines. A woman who tests negative for high-risk HPV can be confidently reassured that she has a very low risk of developing cervical cancer before the next round of screening.
New biomarker tests determine who needs further intervention
HPV infections are common and not all women who become infected with HPV will develop cervical pre-cancer or cancer.3 Women who have abnormal Pap results or positive HPV tests often have a follow-up test called a colposcopy, during which a woman’s cervix is closely examined and a biopsy may be taken to look for abnormal cells. But sending all HPV-positive women for follow-up colposcopy is not practical or cost-efficient and may result in unnecessary treatment of women. Therefore, it is important to determine which women who test positive for HPV are at a greater risk for cervical disease and would benefit from a follow-up colposcopy and biopsy.
A new biomarker-based test identifies those women who have HPV infections that may transform infected cells into cancer cells.14,15 Women who test positive for this particular biomarker would benefit the most from immediate intervention like colposcopy, while women who test negative are at low risk for developing cervical disease.
For women who have colposcopies, a diagnostic confirmation test uses advanced biomarker technology to confirm the presence or absence of precancerous lesions. This improves the ability of pathologists to diagnose cervical disease and clinicians to make treatment decisions.
While diagnosing cervical pre-cancer or cancer with a biopsy can be difficult and false positive or false negative results are possible, biomarker tests are typically very sensitive and accurate and can identify women who have pre-cancer or cancer that is often missed by standard tests.16,17
Greater certainty benefits women and clinicians
By accurately identifying all women at risk of developing cervical cancer with HPV screening and differentiating those who need intervention or treatment from those who do not using biomarker tests, it is possible to spare women from developing a preventable cancer and limit the risks of overtreatment.
“The widespread introduction of advanced screening and diagnostic solutions that address previous limitations is extremely exciting,” said Tim Himes, Roche Cervical Cancer Solutions Lifecycle Leader at Roche Diagnostics. “We have the potential to reduce the risk of cervical pre-cancer or cancer going undetected, which is an important and rewarding step forward. At the same time, we can help minimise the number of women receiving unnecessary procedures.”
“Roche remains deeply committed to safeguarding and improving the health of women,” he said. “We will continue to focus our people and resources on the detection and early intervention of pre-cancerous cervical disease. We share with the global healthcare community the goal of saving lives and preventing unnecessary treatment and worry.”
1. WHO, GLOBOCAN 2012. Estimated Cancer Incidence. Mortality and Prevalence Worldwide in 2012. Available at: http://globocan.iarc.fr/Pages/fact_sheets_population.aspx Last accessed December 2016.
2. CDC. Vaccines and Immunizations. Human Papillomavirus. Available at: http://www.cdc.gov/vaccines/pubs/pinkbook/hpv.html Last Accessed December 2016
3. WHO. Human papillomavirus (HPV) and cervical cancer Available at: http://www.who.int/mediacentre/factsheets/fs380/en/ Last Accessed October 2016
4. National Cancer Institute. Cervical Cancer Screening- for health professionals (PDQ®) Available at: http://www.cancer.gov/cancertopics/pdq/screening/cervical/HealthProfessional#Section_115. Last accessed December 2016
5. Leyden WA et al. J Natl Cancer Inst. 2005;97(9):675-683
6. Andrae B et al. J Natl Cancer Inst. 2008;100(9):622-629
7. Priest P et al. BJOG. 2006;114(4):398-407
8. Centers for Disease Control. Epidemiology and Prevention of Vaccine-Preventable Diseases. The Pink Book: Course Textbook - 12th Edition Second Printing (May 2012). Retrieved from http://www.cdc.gov/vaccines/pubs/pinkbook/hpv.html
9. Cuzick J et al. Int J Cancer. 2006;119(5):1095-1101.
10. de Sanjose S et al. Lancet Oncol. 2010;11:1048-1056.
11. Stoler MH et al. Am J Clin Pathol. 2011;135(3):468-75
12. Wright TC et al. Am J Clin Pathol. 2011;136(4):578-86
13. Wright TC et al. Gynecol Oncol. 2015;136(2):189-197
14. Petry KU et al. Gynecol Oncol. 2011;121(3):505-509
15. Uijterwaal MH et al. Int J Cancer. 2014;136(10):2361-2368
16. Bergeron C et al. Am J Clin Pathol. 2010;133(3):395-406
17. Galgano MT et al. Am J Surg Pathol. 2010;34(8):1077-1087