Continuation of Annual Screening Mammography and Breast Cancer Mortality in Women Older Than 70 Years

Area of Science:

• Oncology
• Public Health
• Geriatric Medicine

Background:

• Established randomized trials demonstrate reduced breast cancer mortality with screening mammography between ages 50-69.
• Evidence is lacking on optimal age to discontinue screening mammography.
• A significant percentage of older women (52% of those 75+) continue to undergo screening mammography.

Purpose of the Study:

• To estimate the impact of continued versus discontinued breast cancer screening on mortality in Medicare beneficiaries aged 70-84 years.
• To evaluate breast cancer screening effectiveness in an older population with longer life expectancies.

Main Methods:

• A large-scale, population-based observational study analyzed data from the U.S. Medicare program (2000-2008).
• The study compared two strategies: continuing annual mammography versus stopping screening.
• Participants included over 1 million beneficiaries aged 70-84 with a 10-year life expectancy and no prior breast cancer diagnosis.

Main Results:

• In women aged 70-74, continuing screening showed a trend towards reduced 8-year breast cancer mortality (risk difference: -1.0 per 1000; HR: 0.78).
• In women aged 75-84, continuing screening demonstrated no substantial reduction in 8-year breast cancer mortality compared to stopping (risk difference: 0.07 per 1000; HR: 1.00).
• Positive predictive value of screening mammography was also assessed by age group.

Conclusions:

• Continuing annual breast cancer screening past age 75 years did not yield substantial reductions in 8-year breast cancer mortality compared to stopping screening.
• Findings suggest that the benefits of mammography screening may diminish significantly in women over 75.
• Further research is warranted to refine screening recommendations for older adults, considering potential harms and benefits.