Abstract 91: Age at Breast Cancer Diagnosis by Ethnicity: An Analysis of the Pathology-Based National Cancer Registry

Abstract Purpose: Breast cancer is the most commonly occurring cancer among women in South Africa and globally. The National Breast Cancer Control Policy recommends biannual provider-initiated clinical breast examination (PISCBE) from the age of 40, printed education material and opportunistic health education on breast self-examination at primary healthcare facilities. We aimed to determine the age at diagnosis and the proportion of women younger than 40 years old diagnosed with breast cancer in South Africa. Methods: We used the National Cancer Registry’s pathology-based registry data of 2022. De-identified data on pathologically diagnosed cancer were analyzed. Age at breast cancer diagnosis for the different population groups was calculated relative to the recommended age of 40 years-old to start routine PISCBE. Age-Specific Incidence Rates (ASIRs) of breast cancer for females under 40 years old by population group were also calculated. Results: Breast cancer accounted for nearly a quarter of the cancers diagnosed in females (24%— 11,020/45,707). Despite the overall median age at diagnosis being 59 years old (IQR: 47–71), about 11% (1,239/11,020) were in the under 40 years. Among the Black population diagnosed with breast cancer, 16% (818/5,000) were less than 40 years old, with some being as young as 20–25 years old (11%; 89/818). About 8% (46/548) and 9% (133/1,560) of the Asian population and Coloured population (Mixed race) respectively were diagnosed before 40 years old, while 6% (242/3,912) of the White population were diagnosed before that age. Overall, the ASIR for breast cancer was highest in the 35–39-year-old group (28/100,000), with the White and Coloured populations being affected the most (96/100,000 and 38/100,000 respectively). The White population had almost five times higher ASIR compared to the Black population (96/100,000 versus 21/100,000). Conclusion: There is a need to consider revising the current age cut-off for PISCBE to ensure early detection and effective breast cancer prevention. At least 10% of women (and more among the Black population) were diagnosed with cancer before they were eligible for screening. Provider training and population awareness needs to be increased to enhance detection and optimize care. Citation Format: Judith Mwansa-Kambafwile, Mazvita Muchengeti, Bilqees Sayed, Nkhensani Mhlanga. Age at Breast Cancer Diagnosis by Ethnicity: An Analysis of the Pathology-Based National Cancer Registry [abstract]. In: Proceedings of the 13th Annual Symposium on Global Cancer Research; 2025 Sep 16. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(12_Suppl):Abstract nr 91.