The rates of cervical cancer in women in the United States may be higher than previously thought, and the disease may arise most often at an age when adequately screened women are advised to stop getting screened. That is the conclusion of a new study, available online in Cancer (DOI: 10.1002/cncr.28548). The results should be taken into consideration when the national guidelines for cervical cancer screening are reviewed, the authors say.
Removal of the uterine cervix through a hysterectomy eliminates a woman's risk of developing cervical cancer, but previous estimates of cervical cancer rates in the United States have included these women in the calculations.
"In order to make accurate estimates of the true rates of cervical cancer by age in the United States 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," explained the first author of the study, Anne Rositch, PhD, of the University of Maryland School of Medicine.
To do so, she and Rebecca G. Nowak, PhD, MPH; and Patti E. Gravitt, PhD, MS, analyzed hysterectomy prevalence and cervical cancer incidence from 2000 to 2009. In this analysis, estimating cervical cancer rates only among women with a cervix, the rates of disease in older women and black women were much higher than previously reported. Overall incidence rates were 11.7 cases per 100,000 women before correcting for hysterectomies, compared with 18.6 per 100,000 after correction.
In addition, previous reports showed that the incidence peaks at age 40 to 44 (15.6 cases per 100,000 women) and then levels off. But after correcting for hysterectomy, the incidence continued to increase with age, peaking at a higher rate (27.4 cases per 100,000 women) and at an older age (65 to 69).
The effect was most pronounced among black women, given their higher prevalence of hysterectomy than white women.
The authors note that their findings should be considered when setting national guidelines for the appropriate age to stop screening for cervical cancer: "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.
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."