Commentary: Cervical Cancer Stands No Chance if We Do These 6 Things
Despite effective vaccines, screening, and treatment, cervical cancer still kills hundreds of thousands of women, most outside rich countries. Experts call for scaling up proven solutions to prevent this.
Cervical health scares have reached mainstream awareness in pop culture, between Abbie in the film 20th Century Women, Hannah on HBO’s Girls, and Sharon on Channel 4’s Catastrophe.
While a terrifying specter to these LA, New York, and London women, cervical cancer isn’t among the top 5 cancer killers in highly developed regions. Eight of every 10 cervical cancers occur in low- and middle-income countries. While this cancer is preventable, over 230,000 women globally die every year–most in low-resource countries, like those in Sub-Saharan Africa.
As the world observes World Cancer Day this year, we issue a challenge to all to remain focused on the continuing challenges preventing us from reaching more girls and women with effective primary and secondary cervical cancer prevention services in low- and middle-income countries. It’s time to take action, to take the tools we have and start building evidence-based programs, with communities, for the future.
Primary Prevention with HPV Vaccines
More than 3 out of 4 women globally will contract HPV, the primary cause of cervical cancer, within their lifetime. Three currently available HPV vaccines have close to 100% efficacy1 at preventing persistent infection and pre-cancerous disease caused by the two HPV types that cause 70% of the world’s cervical cancer, all with minimal and mild adverse reactions. The newest vaccine directly protects against 5 additional HPV types, which together account for another 20% of the world’s cervical cancer.
Vaccines are hailed as the best buy in public health: Compared to the considerable cost of treatment and lost productivity from cervical cancer, vaccinating girls against cervical cancer is usually a cost-effective investment2 for countries, particularly in a low-resource setting.
What’s next in the vaccine landscape?
1. Taking steps to reduce vaccine price and ensure reliable supply. Currently licensed HPV vaccines are expensive compared to older, routine immunizations. A global HPV vaccine supply shortage over the past few years has also affected access for girls in the highest-burden, most price-sensitive countries.
But new vaccines must show equivalence against already-approved vaccines. To do this, companies need lab tests that allow direct comparison of molecular and immunology markers—tests that don’t yet exist. Looking to the future, the U.S. National Cancer Institute has launched a new initiative3 to develop and evaluate this type of lab test, opening the way for the development of new, potentially lower-cost HPV vaccines.
2. Reducing the number of doses. The World Health Organization (WHO) recommends two doses of HPV vaccine for girls aged 9-14, at least 6 months apart. Young people who are 15 years old and older, as well as people with a compromised immune system should get a third dose. Scientists are studying whether or not a single dose, or at least a much lengthier between-dose interval, might be as good as two doses. If the results are promising, this study could remove the logistical challenge of tracking down each girl to administer an additional dose for full coverage and reduce costs.
Secondary Prevention: finding and treating pre-cancers
Tools for early detection and treatment of the precursors to cervical cancer build upon a solid basis of proven interventions. Yet to effectively prevent cervical cancer in low-resource settings, there are remaining challenges:
3. Scaling up the use of vinegar to identify abnormal cells. Cytology screening, wherein lab workers inspect cells from the cervix under the microscope for abnormalities, is relatively costly and requires access to a functioning and staffed laboratory system. Visual Inspection using Acetic Acid (VIA) technique, which has been used for over a decade, is a safe, effective alternative for onsite screening where there is no lab equipment or personnel. Most well trained health workers can perform this task—task shifting is an important cost savings technique. However, VIA requires robust quality assurance and a large pool of trained providers if it is to be delivered to women at scale.
3. Reducing test prices. HPV DNA tests are quite accurate at flagging persistent and chronic infection with cancer causing human papilloma virus. Also, while cytology and VIA require pelvic examinations, women can collect HPV DNA tests at home or at a health facility. Facilities can process many tests together to maximize cost effectiveness. However, the tests require an initial start-up investment as well as continuing financing to purchase test kits and supplies.
4. Expanding options for freezing therapies. Cryotherapy currently uses compressed nitrous oxide or carbon dioxide to freeze abnormal cells off the cervix so normal ones can grow back. Providers who aren’t physicians can be trained to provide the therapy, but machines require reliable gas supply as well as equipment maintenance and transport. Clinical trials are underway to develop new and more practical delivery approaches. Two promising developments are the gasless Cryopen and the dry-ice based CryoPop4. Both destroy the pre-cancerous lesion by freezing the offensive tissue.
5. Heating to destroy precancerous cells. Thermal Coagulation, in which heat at 100-120 degree Celsius is applied to the cervix to destroy precancer lesions, is being clinically and programmatically evaluated to determine its effectiveness and safety by the International Agency for Research in Cancer.
What lies ahead?
We have powerful tools: safe, effective vaccines, and many tested strategies to prevent cervical cancer. We welcome your ideas about additional opportunities to leap across barriers we’ve noted, as well as many others, and address this pervasive threat to women the world over.
Mary Carol Jennings, MD, MPH, is a public health physician and a scientist at the International Vaccine Access Center, in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health. She serves as the IVAC HPV Technical Lead, and her research and work focus on innovative ways to ensure equitable vaccine delivery. Reach her at email@example.com
Ricky Lu, MD, MPH is a public health physician and directs the FP/RH and Cervical Cancer Prevention unit at Jhpiego, an affiliate of the Johns Hopkins University and an implementing agency operating in over 40 countries globally. He leads the Jhpiego cervical cancer prevention effort partnering with MOHs to strengthen their prevention and control program. Reach him at firstname.lastname@example.org
1Chow EP, Danielewski JA, Fehler G, Tabrizi SN, Law MG, Bradshaw CS, Garland SM, Chen MY, Fairley CK. Human papillomavirus in young women with chlamydia trachomatis infection 7 years after the australian human papillomavirus vaccination programme: A cross-sectional study. The Lancet Infectious Diseases 2015;15(11):1314-23.
2Brisson M, Jit M, Boily M, Laprise J, Martin D, Drolet M, Alary M, Benard E. Modelling estimates of the incremental effectiveness & cost-effectiveness of HPV vaccination: Executive summary. ; 2016. Available from: http://www.who.int/immunization/sage/meetings/2016/october/07_Modelling_HPV_immunization_strategies.pdf?ua=1
3Cole M. New HPV Serology Laboratory Aims to Standardize Assays and Contribute to Vaccine Implementation and Access [Internet]National Cancer Institute: Frederick National Laboratory for Cancer Research; accessed Jan 21 2018, Available from:https://frederick.cancer.gov/news/new-hpv-serology-laboratory-aims-standardize-assays-and-contribute-vaccine-implementation-and
4Varady, M. et al. (2015) CryoPop: Merging design with demand to build a low-cost cervical cancer prevention toolAnnals of Global Health , Volume 81 , Issue 1 , 201. Retrieved from: http://dx.doi.org/10.1016/j.aogh.2015.02.963