Performance analysis of screening mammography in Asian women under 40 years

Background: Screening mammography performance among young women remains uncertain in East Asia, where the proportion of young breast cancer patients is higher than that in Western countries. Thus, we analyzed the performance of screening mammography in women under 40 years in comparison with older age groups. Methods: This retrospective study comprised 95,431 Asian women with 197,525 screening mammograms. The reference standard was determined by linkage to the national cancer registry data and the 12-month follow-up outcomes after the index mammogram. The performance metrics included sensitivity, specificity, cancer detection rate (CDR), positive predictive value (PPV), recall rate, and areas under the receiver operating characteristic curve (AUCs), with comparisons across age groups (30 s, 40 s, and ≥ 50 s). Results: For young women aged < 40 years, sensitivity and AUC (95% confidence interval [CI]) of screening mammography were 60.4% (50.4–69.7) and 0.73 (0.68–0.77), respectively, with no significant difference compared to women in their 40 s (sensitivity: 64.0% [95% CI: 57.8–69.8], P = 0.52; AUC: 0.75 [95% CI: 0.73–0.78], P = 0.35). The CDR (95% CI) was 0.8 (0.6–1.1) per 1,000 mammograms for young women, poorer than 1.8 (1.6–2.1) per 1,000 mammograms for women in their 40 s (P < 0.001). The PPV and recall rate (95% CI) for young women were 0.6% (0.4–0.7) and 14.9% (14.6–15.1), poorer than 1.4% (1.2–1.6) and 13.3% (13.1–13.5) for women in their 40 s (P < 0.001), respectively. Conclusion: The accuracy of screening mammography for young women in their 30 s was not significantly different from that for women in their 40 s, but the cancer detection and recall rates were poorer.