Largest NHS Study: Google AI Matches or Exceeds Radiologists in Breast Cancer Screening Across 175,000 Women
A landmark NHS study of 175,000 women found that Google's AI, used as a second reader in breast cancer screening, detected more invasive cancers, generated fewer false positives, reduced first-time recall rates by 39.3%, and cut scan-reading time by nearly a third.
The largest NHS study to date on AI in breast cancer screening has found that Google's AI system matches or exceeds human radiologists across all key performance metrics. The study, conducted by Imperial College London in partnership with Google, the universities of Cambridge and Surrey, and multiple NHS Trusts, analyzed mammograms from 175,000 women.
When AI served as the second reader — replacing one of the two human radiologists in the UK's standard double-reading protocol — the cancer detection rate rose from 7.54 to 9.33 per 1,000 women. The AI generated fewer false positives, reduced recall rates for first-time screenings by 39.3%, and cut scan-reading time by nearly a third.
The AI also detected 25% of interval cancers — cancers that appear between routine screening appointments and are typically missed by the screening program entirely. This finding is particularly significant because interval cancers tend to be more aggressive and carry worse prognoses.
The findings, published in two linked papers in Nature Cancer, arrive at a critical moment. The UK faces a severe radiologist shortage, and breast cancer affects one woman every 10 minutes. The researchers argue these results demonstrate 'the potential for more women to be diagnosed and treated sooner, while reducing radiologists' workload' — a rare case where AI simultaneously improves clinical outcomes and operational efficiency.