A decades-long downward trend in cervical cancer incidence and death rates has reversed for women in low-income areas, leading to widening health disparities. These disparities and their effects on the lives of women are troubling to researchers because cervical cancer is preventable with appropriate screening and care.
Past studies have suggested an increase in incidence could be occurring in the lowest-income counties in the U.S., but the evidence wasn't conclusive. Now, for the first time, a group of researchers has documented a definite increase in both incidence and death rates.
"Cervical cancer incidence has increased in the lowest-income counties overall, but the increase is driven by a very rapid rise in white low-income women," explained Ashish Deshmukh, Ph.D., co-senior author of the study and co-leader of the Cancer Control research program at MUSC Hollings Cancer Center.
"What's so troubling is that that the increase is pronounced for late-stage, distant cancer, and, as a result, there was a rise in mortality," he said.
A reversal in cervical cancer deaths and a much higher death rate among Black women also worried researchers, as it reflects a marker of disparities.
The research is published this month in the International Journal of Cancer.
"The findings are quite disturbing, highlighting stark differences across ethnic groups compounded by income disparities," said lead author Trisha Amboree, Ph.D., a postdoctoral fellow at The University of Texas MD Anderson Cancer Center. "The upward trend in mortality among Black women in low-income counties, despite decreasing diagnoses in this group, suggests potential disruptions in timely treatment and follow-up care and calls for more research to understand the underlying factors."
"The question that we always ask is, 'Is the increase real, or is it because we're screening more women?' Speculation in the past was maybe we were screening more women. For instance, Medicaid expansion may have contributed to the increase. But it seems that the increase is real."Ashish Deshmukh, Ph.D.
Cancer Control Program
The research team parsed data by race, median county income and cervical cancer diagnoses and deaths. In the early 2000s, cervical cancer rates were declining across all groups, although some started with higher incidence rates than others.
But in 2007, the rate for white women in low-income counties began to increase. From 2007 to 2019, the rate of cervical cancer incidence increased by 4.4% a year for this group.
"The question that we always ask is, 'Is the increase real, or is it because we're screening more women?' Speculation in the past was maybe we were screening more women. For instance, Medicaid expansion may have contributed to the increase," Deshmukh said. "But it seems that the increase is real."
Cancers are being found at a late stage, after they've spread beyond the cervix and are more difficult to treat. This suggests, Deshmukh said, that there's a disruption somewhere along the continuum of screening and treatment.
Most cervical cancers are caused by the human papillomavirus (HPV), an exceedingly common virus. A few strains are considered high-risk for causing cancer, including head and neck, cervical, anal, penile, vulvar and vaginal.
However, the HPV vaccine protects against infection with the high-risk strains. Regular screening, with Pap smears, HPV testing or a combination, can detect precancerous changes that can then be treated before cancer develops.
Screening without follow-up treatment, however, doesn't help women.
"The rise in death rates – it's unacceptable," Deshmukh said.
Hispanic women in low-income counties also saw an increase in cervical cancer incidence, although that, too, was not statistically significant. However, Hispanic women in low-income counties had the highest overall rate of cervical cancer.
Knowing that there are barriers to receiving care, Hollings has two mobile units that travel the state to bring care into communities. The first, the Mobile Vaccination Unit, offers HPV and school-required vaccines as well as general cancer education. The second, the Mobile Health Unit, provides mammograms, Pap smears and skin checks.
Deshmukh has previously collaborated on research projects investigating cervical cancer in specific geographies or populations.
Last fall, for example, he published a study showing that cervical cancer death rates were higher in Appalachian counties in Kentucky than in non-Appalachian counties in Kentucky. And in 2022, he documented an increase in cervical cancer rates in women in their early 30s.
Different issues could be at play. Colleagues in Kentucky reported that they heard from frontline workers that women faced more barriers to treatment, including health care facility closures. On a national level, screening rates have decreased among younger women. While they can't say with certainty that either of these possible reasons is connected to the increases reported in this study, they do give a direction for future studies, Deshmukh said.
"There are still major knowledge gaps," he said. "But our ongoing work will allow us to provide answers in the future."
