Cervical cancer deaths drop among younger women; study credits HPV vaccine

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Cervical cancer deaths among women younger than 25 have plummeted in recent years, the likely result of vaccinating adolescents against human papillomavirus, or HPV, high-risk strains of which cause the cancer, researchers said.

“This is a huge public-health success story,” said Ashish Deshmukh, co-leader of the cancer prevention and control research program at the Medical University of South Carolina’s (MUSC) Hollings Cancer Center, and senior author of research recently published in JAMA Network. “Vaccination is the only explanation for this startling and substantial decline.”

Previous studies have looked at the rates of HPV – a sexually transmitted virus – infection, early signs of pre-cancer, and cervical cancer since the introduction of the vaccine, concluding that these also have fallen.

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But this study is the first to show that the vaccine saves lives, researchers said. The scientists found a steep 62 percent drop in mortality from cervical cancer among younger women in the United States during the last decade.

However, in a worrisome side note, they cited statistics from the Centers for Disease Control and Prevention, which found that HPV vaccination rates have been waning, dropping from 79.3 percent in 2022 to 75.9 percent in 2023, among U.S. adolescents who recently became eligible for the vaccine.

The falling vaccination rates are occurring during a period of growing vaccine skepticism generally, probably fueled by a proliferation of vaccine disinformation on social media, Deshmukh said. Also, the pandemic itself disrupted many preventive health services as people avoided going to doctors’ offices in person, fearing coronavirus infection.

“There is more disinformation on social media on HPV than positive information,” Deshmukh said. “People continue to question its safety. This vaccine has been extensively studied. It’s a safe vaccine, with no major side effects, that prevents cancer.”

Jay Berzofsky, chief of the vaccine branch of the National Cancer Institute’s (NCI) center for cancer research, who was not involved in the study, described the declining vaccination rate as “disturbing,” and called for “a greater effort” to convince parents that HPV vaccination “can save their children’s lives in the future.”

There are more than 200 different strains of HPV, although only 12 are considered high-risk, according to the NCI. “Long-lasting – that is, persistent – infection with high-risk types of HPV causes virtually all cervical cancers, as well as cancer in other parts of the body where HPV infects cells,” said Nicolas Wentzensen, deputy director of NCI’s clinical genetics branch and a co-author of the paper

In addition to cervical cancer, HPV also causes five other cancers – oropharyngeal, or throat cancer, which afflicts both men and women; anal cancer, also in both sexes; vulvar and vaginal cancer in women; and penile cancer in men. It also can cause genital warts.

The HPV vaccine was introduced in 2006 and is recommended for people ages 9 to 45. The most recent version protects against nine HPV types, including 16 and 18 that cause most HPV cancers, according to the CDC.

The women in this study represent the first group vaccinated, allowing scientists to evaluate its early effect.

Cervical cancer is diagnosed most often in women ages 35-44, according to the American Cancer Society, and is rare in women younger than 25, but it does occur, Deshmukh said.

“It is heartbreaking to see anyone with a new diagnosis of cervical cancer, but any cancer diagnosis is especially poignant in a young person who is just starting their adult life,” said Ursula A. Matulonis, chief of the division of gynecologic oncology at the Dana-Farber Cancer Institute, who was not involved in the research

HPV vaccination is “critical” to reducing cases and deaths, making this study “very exciting and noteworthy news,” she added.

Deshmukh said he expects to see cancer deaths continue to fall as this group ages. Women who were 25 in 2021, the final year included in this study, would have been 10 years old when the vaccine was introduced.

“This is the first cohort likely to have benefited from this vaccine,” Deshmukh said. “It’s likely we will see a similar decline 10 to 15 years from now because there is a higher burden of this cancer in women in their 30s and 40s.”

Cervical cancer grows slowly and can be treated if caught early with HPV screening, known as a Pap smear. For these reasons, “some might argue that vaccines aren’t that important,” said Robert T. Schooley, an infectious diseases specialist at the University of California at San Diego, who was not involved in the research.

But this study shows that “women were dying of cervical cancer despite screening and treatment before the vaccines, and that with the vaccination program, the number of deaths has fallen further,” Schooley said.

This decline probably will accelerate as this group grows older, he said. “This couldn’t have been studied in older women because HPV vaccines were not available when they were at the peak age to become HPV-infected,” Schooley said.

Wentzensen said, “We can expect much larger reductions in absolute numbers of cancer cases in vaccinated women compared to unvaccinated women” once they age.

“Cervical cancer elimination is possible in the next decades if vaccination and screening are widely implemented, and high participation rates can be achieved,” said Wentzensen, also the head of the clinical epidemiology unit and senior investigator in the division of cancer epidemiology and genetics.

Using data from the National Center for Health Statistics, researchers looked at cervical cancer deaths in three-year blocks of time. Between 1992 and 2021, there were 398 cervical cancer deaths reported among women younger than 25. During the period of 1992-1994 to 2013-2015, mortality from cervical cancer gradually declined 3.7 percent each year. The period of 2013-2015 to 2019-2021 saw an even greater drop to 15.2 percent annually, according to the study.

The number of deaths decreased from 55 in 1992-1994 to 35 in 2013-2015 to 13 in 2019-2021.

“Assuming that the trend from 1992-1994 to 2013-2015 would have continued, an estimated 26 additional cervical cancer deaths would have been expected to occur between 2016 to 2021, based on projected mortality rates,” the authors wrote.

The American Cancer Society has estimated about 13,820 cervical cancer cases diagnosed in 2024, with about 4,360 deaths. Globally, cervical cancer is the fourth most-common cancer in both incidence and mortality in women, and the leading cause of cancer death in 37 countries, according to the organization.

“The opportunity to truly end cervical cancer as we know it is well within our grasp,” said Karen Knudsen, former chief executive of the American Cancer Society. “These data also give strong confidence that the other HPV-driven cancers, which affect both men and women, can be similarly prevented through the protection that HPV vaccination affords.”

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