(HealthDay News) — Continued breast cancer screening among women aged 70 years and older is associated with an increased incidence of breast cancer, indicating overdiagnosis, according to a study published online Aug. 8 in the Annals of Internal Medicine.
Ilana B. Richman, M.D., from the Yale School of Medicine in New Haven, Connecticut, and colleagues estimated overdiagnosis in a retrospective cohort study comparing the cumulative incidence of breast cancer among women aged 70 years and older who had recently been screened and who continued or did not continue screening in the next interval. Data were included for 54,635 women, who were followed for breast cancer diagnoses and breast cancer death for up to 15 years of follow-up.
The researchers found that the adjusted cumulative incidence of breast cancer was 6.1 versus 4.2 cases per 100 screened and unscreened women aged 70 to 74 years. Among screened women, an estimated 31 percent of breast cancers were potentially overdiagnosed. The cumulative incidence was 4.9 versus 2.6 per 100 screened and unscreened women among those aged 75 to 84 years, with potential overdiagnosis for 47 percent of cases. The cumulative incidence was 2.8 and 1.3 per 100 screened and unscreened women, respectively, aged 85 years and older, with overdiagnosis of up to 54 percent. No significant reductions were seen in breast cancer-specific death associated with screening.
“Overdiagnosis should be explicitly considered when making screening decisions, along with considering possible benefits of screening,” the authors write.
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