Abstract
OBJECTIVE: Breast cancer accounts for 31.8% of female cancers in Saudi Arabia, with 56% of cases diagnosed before age 50, 14 years younger than in Western countries. Aggressive subtypes (TNBC: 18-24%; HER2+: 25-28%) are common, and dense breast tissue reduces the effectiveness of mammography. Currently, no age-specific screening protocols exist for this unique epidemiological profile. This study aimed to assess the age-specific diagnostic accuracy of mammography, ultrasound, and magnetic resonance imaging (MRI), and to characterize molecular subtype distribution in Saudi breast cancer patients to guide personalized screening guidelines. MATERIAL AND METHODS: A retrospective cohort study was conducted at a tertiary care center in Riyadh, Saudi Arabia (January 2021-December 2023). Medical records of 148 women aged 30-70 with histopathologically confirmed breast cancer (BI-RADS 4/5) were analyzed. The sensitivity and specificity of imaging modalities were assessed across age groups (30-39, 40-49, 50-59, ≥60 years). Subtype distribution and breast density (BI-RADS A-D) were correlated with imaging performance using chi-square tests and logistic regression (SPSS v28, STARD 2015 guidelines). RESULTS: The mean age was 48 years, with 56.4% of cases occurring in women under 50 (peak incidence: 40-49 years, 34.1%). Ultrasound sensitivity exceeded mammography in women under 50 (85.3% vs. 74.5%, p<0.01), while MRI demonstrated the highest overall accuracy (91.7%, 95% confidence interval 89.2-93.5). TNBC prevalence decreased with age (24.7% in 30-39 years to 12.0% in ≥60 years, p<0.01), while invasive lobular carcinoma incidence doubled (8.2% to 18.0%, p<0.001). Delayed diagnosis (>60 days) lowered 2-year survival by 21% (p=0.003). CONCLUSION: Ultrasound is more effective than mammography for early detection in Saudi women under 50 years old, while MRI remains highly accurate across all age groups. National screening guidelines should adopt biennial ultrasound-first screening starting at age 40, with MRI reserved for high-risk cases and BI-RADS 3-4 lesions.