Study is first solid evidence that introduction of HPV vaccines may be a factor in the reduction in rates of cervical cancer among those who were vaccinated nearly 20 years ago
Research conducted at the Medical University of South Carolina (MUSC) in Charleston establishes a strong link between the marked decline in cervical cancer cases among young women in American and the introduction of the Human Papillomavirus (HPV) vaccine in 2006, according to reporting by Science News, a journal of the Society for Science.
This success story confirms that a better understanding of what causes cervical cancer—when combined with the development of clinical laboratory tests that detect the HPV virus—were key developments in the fight against this deadly disease.
The study, led by cancer population scientist Ashish Deshmukh, PhD, epidemiologist, professor of public health sciences and co-leader of the cancer control program at the Hollings Cancer Center (HCC) at MUSC, found the connection between the decline in cervical cancer rates and the adoption of the HPV vaccine.
Pathologists and clinical laboratory managers will want to monitor the worldwide effort to eradicate cervical cancer, as many countries focus their efforts on HPV vaccine compliance. The scientists published their findings in the Journal of the American Medical Association (JAMA) titled, “Cervical Cancer Mortality among US Women Younger than 25 Years, 1992-2021.”
The scientists published their findings in the Journal of the American Medical Association (JAMA) titled, “Cervical Cancer Mortality among US Women Younger than 25 Years, 1992-2021.”
“We had a hypothesis that since it’s been almost 16 years, that maybe we might be starting to see [the] initial impact of HPV vaccination on cervical cancer deaths, and that’s exactly what we observed,” Ashish Deshmukh PhD (above), epidemiologist and professor of public health sciences at Medical University of South Carolina in Charleston, told Science News. The MUSC study provides important findings for clinical laboratories and anatomic pathologists providing vaccinations against Human Papillomavirus. (Photo copyright: Medical University of South Carolina.)
MUSC Study Details
Deshmukh’s team examined cervical cancer mortality rates of women younger than 25 from 1992-2021. The team divided data into 3-year periods, noting a “gradual decline in cervical cancer deaths of almost 4%” which brought deaths to .02 per 100,000 people from 2013-2015, Science News reported, adding that the researchers speculated that the “steady drop might be due to improved prior prevention and screening methods for cervical cancer.”
The death rate for cervical cancer continued to trend downward with “a dramatic reduction in mortality over just 60%,” arriving at .007 deaths per 100,000 according to the 2019-2021 data, Science News continued.
In their JAMA article, the MUSC researchers noted a continued positive shift toward lower cervical cancer rates beyond 2021, with a 12% per year decline and 65% reduction overall.
“They’re seeing this precipitous drop in mortality at the time that we would be expecting to see it due to vaccination,” Emily Burger, PhD, professor at the University of Oslo and research scientist at Harvard T.H. Chan School of Public Health told Science News. “Ultimately, we hope we are preventing mortality and death [with the introduction of vaccines], and this study is really supporting that conclusion.”
Nonetheless, a definitive connection to the HPV vaccine was not possible to determine “because it’s unclear whether the women in the study cohort were, in fact, vaccinated,” Science News reported.
Development of the PAP Smear
Cervical cancer was first discovered in 1886. At that time pathologists relied on “examination of tissue biopsies derived from an observable lesion,” LabTAG noted. It was George Papanicolaou, PhD—considered to be the father of cytology—who determined in 1943 that more could be observed via a surface biopsy under a microscope. The Pap Smear was born.
The Pap Smear, for which wider screening began in the US in the late 1950s and 1960s, began to reduce deaths from cervical cancer by the 1990s. But women who did not get an annual pap were the ones generally to be diagnosed with advanced cervical cancer.
By the 1990s, pap smear testing was a major business for clinical laboratories and pathology groups. Fifty-five million pap tests were done annually in the 1990s.
In 2004, clinical laboratories began HPV testing. Then came the HPV vaccine. Introduced in 2006, HPV vaccine programs focused on 12-15 year-old girls with hopes of preventing cervical cancer.
Clinical laboratories in the US today perform many fewer Pap smear tests.
Global Fight against HPV Continues
Many countries are pushing for full eradication of cervical cancer. In “Australia Moves to Fully Eliminate Cervical Cancer by 2035, Especially in Underserved and Diverse Populations,” Dark Daily reported on the land down under’s creation of its National Strategy for the Elimination of Cervical Cancer program in 2010.
Norway is pushing for a full eradication by 2039.
While efforts overseas appear to focus on HPV vaccine requirements, the US has been hesitant to do the same. The District of Columbia, Hawaii, Virginia, and Rhode Island are the only states to require it by grade seven, Immunize.org notes. Various reasons have kept it from being required in the US, including fear that it might encourage sexual activity in teens.
There is hope that, with a larger focus on cervical cancer, more deaths can be prevented since the cancer itself is slow growing. “When we look at HPV vaccination coverage in the US, we haven’t reached our goal. We have to do better in terms of improving vaccination rates,” Deshmukh told Science News.
As scientists continue to gain a better understanding of causes and prevention of cervical cancer, new clinical laboratory tests may be developed to detect HPV. Thus, lab managers will want to stay in touch with current research as it will surely impact the testing performed by labs in the future.
—Kristin Althea O’Connor
Related Information:
Cervical Cancer Mortality among US Women Younger than 25 Years, 1992–2021
Cervical Cancer Deaths Are Plummeting among Young US Women
The History of Cervical Cancer Screening
HPV (Human Papillomavirus) Vaccine Requirements for Secondary School