A new study confirms that not only does breast cancer screening save lives, but it also improves survival in women with late-stage disease. Researchers found that women with stage IV breast cancer had a survival rate over three times higher if their disease was detected with screening, thanks largely to its role in driving treatment.
The “Mammography Wars” over breast cancer screening’s effectiveness raged from the 1980s to the 2010s, but eventually were decided in mammography’s favor.
- Multiple research studies have demonstrated that the combination of early detection and more effective treatments improve breast cancer survival. The USPSTF’s 2023 shift back to recommending that screening start at 40 settled the issue.
But pockets of anti-screening resistance remain, with screening skeptics publishing several studies since the USPSTF change questioning the value not only of mammography but also other cancer screening tests.
- So it’s more important than ever to demonstrate cancer screening’s value.
The new study in the Journal of the National Cancer Institute does just that by analyzing screening’s impact on survival rates in women diagnosed with stage IV disease who had been invited to Denmark’s national breast screening program (not all women completed mammography despite getting invited).
- In all, 32.8k women with breast cancer were included, of whom 8% presented with stage III or stage IV cancer.
The researchers found that for women with stage IV breast cancer…
- Five-year survival was over 2X higher for women with screen-detected cancer versus women who were never screened (75% vs. 32%).
- Ten-year survival was over 3X higher (62% vs. 17%).
- Women with later-stage disease detected by screening had survival rates over five years comparable to women with disease one stage lower who were never screened.
- Survival rates were strongly influenced by treatment type, with surgical treatment showing the longest median survival versus non-surgical treatment and no treatment (6, 2, and 0.1 years, respectively).
The big difference in survival was driven by the fact that women with screen-detected cancers were far more likely to get surgical treatment, and to subsequently have better 10-year survival rates than those treated without surgery (60% vs. 8%).
The Takeaway
The new study once again proves the value of screening mammography, but it goes beyond just showing that screening causes a stage shift to earlier diagnosis. Even in women with late-stage disease, screening is driving more effective treatment that is proving invaluable in saving women’s lives.


