Does Mammography Improve Breast Cancer Outcomes in Women Over 70?

Breast cancer screening has long been known to improve early detection and survival in younger age groups. But does this benefit continue as women age? The value of mammography in women aged 70 or older remains debated. On April 15, 2025, JAMA Network Open published a new study offering strong evidence that mammography may still save lives in this age group.

Study Background: A Large Dataset of 13028 Women

The study analyzed US data from 2010-2017 on ER-positive or HER2-negative breast cancer diagnosed among 13028 women aged 70 or older. All participants had been enrolled in Medicare A and B for 5 years before and 1 year after diagnosis.

Screening History:

• 77.5% had undergone mammography at least 1 time.

• 31% had undergone 2 screening mammograms, and 45.6% had undergone 3-4.

• 22.5% had never undergone mammography.

Diagnostic mammograms performed after symptoms were distinguished from routine screening mammograms.

Findings: A Marked Increase in Early Diagnosis

Stage at Diagnosis:

• Overall, 70.7% were diagnosed at a very early stage (T1N0) .

• Among women without a screening history, 43.4% were diagnosed at a late stage, compared with only 25.1% among those screened.

Women with a mammography history had a 54% lower likelihood of late-stage diagnosis

• Adjusted odds ratio (aOR): 0.46

Factors increasing the risk of late-stage diagnosis:

• Lower socioeconomic status (Medicare/Medicaid dual enrollment): aOR 1.17

• Higher poverty rate: aOR 1.21

• Higher tumor grade (grade 3-4): aOR 4.90

Breast Cancer Mortality: Screened Women Have Half the Risk

The overall breast cancer-specific mortality rate was 4.4% in the study.

• The mortality rate was 8% among women never screened

• It was 3.3% among those with a screening history (statistically significant; P < 0.001)

Women with a mammography history had a 37% lower risk of death

• Adjusted hazard ratio (aHR): 0.63

In addition, women who had undergone 3-4 mammogramshad a lower risk of death than those screened only once (aHR 0.63).

Compared with women aged 70-74, those aged 85 or older had a risk of death 2.28 times higher .

What Do These Findings Mean?

Regular mammography screening has the potential to improve breast cancer outcomes even in older women. Assessments that ignore screening history may also be misleading.

Conclusion: Screening Knows No Age Limit

This large-scale study strongly demonstrates that regular mammography remains critical for early diagnosis and survival even in women over 70 . Particularly in ER-positive disease, women with a screening history are diagnosed earlier and have substantially lower cancer-related mortality.