Annual breast screening mammograms after 75 years of age did significantly reduce breast cancer-related mortality, according to a new study published in the Annals of Internal Medicine.
The large-scale, population-based, observational study compared outcomes related to annual mammography versus stopping screening. They used 1999 to 2008 Medicare data to identify 1,058,013 Medicare beneficiaries aged 70 to 84 years who had a life expectancy of at least 10 years, had no previous breast cancer diagnosis, and underwent screening mammography.
Age impacts necessity of mammograms
During follow-up, researchers identified 1,533 breast cancer deaths among those who continued screening and 1,304 deaths in those who stopped screening.
In women aged 70 to 74 years, the estimated difference in eight-year risk for breast cancer death between continuing and stopping screening was −1.0 (95% CI, −2.3 to 0.1) deaths per 1,000 women (hazard ratio, 0.78; 95% CI, 0.63- 0.95), which favors continuing screening.
However, in those aged 75 to 84 years, the corresponding risk difference was 0.07 (95% CI, −0.93 to 1.3) deaths per 1,000 women (HR, 1.00; 95% CI, 0.83-1.19), conferring no substantial reductions in eight-year breast cancer mortality compared with stopping screening.
In both age groups, researchers found that women diagnosed with breast cancer who did not undergo further screening were more likely to undergo chemotherapy than those who continued screening; however, they were less likely to have other aggressive treatments, such as radiotherapy and lumpectomies.