New research published in the journal Cancer suggests that current cervical cancer screening guidelines underestimate incidence rates of the disease in the US, as well as the risk of older women developing cervical cancer.
Under current guidelines set by the American Cancer Society, women between the ages of 21 and 29 should be screened for cervical cancer every 3 years, while women aged between 30 and 65 should be screened every 5 years.
However, recommendations state that women over the age of 65 who have had regular cervical cancer screening with normal results should not continue to be screened.
But according to the research team, led by Anne Rositch, PhD, of the University of Maryland School of Medicine, women over the age of 65 are at highest risk of the disease - something that is not reflected in current US cervical cancer incidence rates.
The problem with past estimates of cervical cancer rates in the US, the researchers say, is that women who have undergone a hysterectomy - removal of the uterus - are still included in calculations, even though the procedure has eliminated their risk of cervical cancer.
"In order to make accurate estimates of the true rates of cervical cancer by age in the US and monitor trends in the occurrence of disease, it is important to calculate the occurrence of cervical cancer only among women who are at risk," explains Rositch.
Therefore, the team set out to gain a truer reflection of the prevalence of cervical cancer among American women. They did this by assessing cervical cancer incidence and hysterectomy prevalence between 2000 and 2009.
Cervical cancer risk 'highest for women aged between 65 and 69'
The researchers found that when they eliminated women who had a hysterectomy, cervical cancer rates were much higher than past estimates, particularly among older women.
After eliminating women who had a hysterectomy in the US between 2000 and 2009, researchers found that women are most at risk of cervical cancer between the ages of 65 and 69.
Before accounting for hysterectomies, overall cervical cancer incidence rates stood at 11.7 cases per 100,000 women. When taking hysterectomies out of the equation, incidence rates stood at 18.6 per 100,000.
The researchers note that past research has indicated that cervical cancer incidence rates are highest between the ages of 40 and 44, at 15.6 per 100,000, before leveling off.
However, once the investigators had eliminated women who had hysterectomies, they found that overall incidence rates increased with age, peaking at 24.7 cases per 100,000 for women aged between 65 and 69 years. This was even more pronounced among black women of this age group, at 53.0 cases per 100,000
The team also found higher incidence among black women of all age groups than previously reported. Before correcting for hysterectomies, figures suggested that black women had a 62% higher rate of cervical cancer than white women. But after eliminating hysterectomies, the team found black women actually had an 89% higher rate than white women.
Current screening guidelines 'should be reviewed'
Based on these findings, the researchers note that existing national cervical cancer screening guidelines should be reviewed.
"Current guidelines recommend exiting women with recent negative screening from routine screening at age 65 years, and yet our corrected calculations show that women just past this age have the highest rate of cervical cancer," says senior study author Patti Gravitt, PhD, of the Johns Hopkins Bloomberg School of Public Health in Baltimore, MD, adding:
"It will be important to clarify in future studies whether the continued increase in cancer rates with age and the higher rates in black women represent a failure in our screening programs or a failure of the women to be screened, so that appropriate interventions can be developed to reduce the burden of cancer in these women."
The researchers conclude that although many cases of cervical cancer have been prevented as a result of early detection and treatment, their findings highlight that the disease remains a major problem. Therefore, they stress the need for a broader uptake of the human papillomavirus vaccine for prevention of cervical cancer in the US.
Medical News Today recently reported that the Food and Drug Administration have approved the first HPV test for primary screening of cervical cancer.
In a spotlight feature earlier this year, we discussed the importance of regular cervical cancer screening and reported on the signs and symptoms of the disease to look out for.