It may be time to rethink US screening guidelines for cervical cancer in older women. A new study has found that cervical cancer rates in women aged 65 to 69 years and in African-American women may be higher than previously recognized.
Researchers at the University of Maryland School of Medicine examined Surveillance, Epidemiology, and End Results (SEER) data from 2000 to 2009 and took into account the prevalence of hysterectomy.
They found that, after correcting for hysterectomy, there were higher age-specific cervical cancer rates with a shift in the peak incidence in older women. The researchers also found a significant race disparity. Previous research estimated the average annual age-standardized rate of cervical cancer was 11.7 cases per 100,000. However, after correcting for hysterectomy status, the rate was 18.6 cases per 100,000.
“While doing a comprehensive review of the literature to understand the current data on risk of cervical cancer in older women, it seemed hysterectomy was not being fully taken into account in some studies,” said study investigator Anne Rositch, PhD, who is an assistant professor of epidemiology and public health at the University of Maryland School of Medicine in Baltimore, Maryland.
“We used the national cancer incidence data to calculate the incidence rates of cervical cancer by age using a standard, uncorrected census population denominator, and then again using a denominator where we removed the proportion of women who self-reported having had a hysterectomy.”
She and her colleagues reported in the journal Cancer that the incidence of cervical cancer steadily increased with age and peaked at a higher rate and at an older age (65 to 69 years).1 The current US cervical cancer screening guidelines do not recommend routine Pap smears for women over age 65 if their prior test results have been normal.
The researchers found the prevalence of hysterectomy in women aged 20 and older was 20.1% and the prevalence was highest among women aged 75 to 84. After correcting for hysterectomy status, increased risk in cervical cancer climbed steadily with age up to 53.0 cases per 100,000 women at age 65 to 69 years among African-American women. This was an increase of 126% compared with the uncorrected rates.1
“We found that, because older women and African-American women had the highest prevalence of hysterectomy, the corrected rate estimates resulted in the largest increase for these groups of women compared to the uncorrected rates. We found that incidence rates of cervical cancer increased with age up to 65 to 69 years, unlike the uncorrected rates that tapered off after age 45,” explained Dr. Rositch.
She and her colleagues pointed out that complete hysterectomy confers protection against future invasive cervical cancer so previous estimates of cervical cancer risk may have been misleading. “To understand both the clinical and policy implications, it will be important to conduct additional research to understand whether the high rates in these two groups of women are due to screening failures (screening failed to detect the cervical precancers and cancers) or failure to be screened,” said Dr. Rositch.