Abstract Introduction: Breast cancer risk models, including the NIH Breast Cancer Risk Assessment Tool (BCRAT) based on the Gail Model, are known to be less accurate for Hispanic/Latina women than for white or African American/Black women due to underrepresentation in model development. This limitation introduces uncertainty in risk estimation and highlights the need for studies involving diverse populations. Caribbean women in Puerto Rico are particularly underrepresented in breast cancer risk research. This study evaluates 5-year and lifetime invasive breast cancer risk scores among Puerto Rican women using the BCRAT and examines the association between self-perceived skin tone and high-risk classification. Methods: A case-control analysis was conducted with 75 Puerto Rican women, including confirmed breast cancer cases and controls. The NIH BCRAT was used to estimate absolute risk of developing invasive breast cancer over the next 5 years and up to age 90 (lifetime). Risk calculations were based on personal medical and reproductive history (age, age at menarche, number of breast biopsies, age at first birth), and history of breast cancer in first-degree relatives (mother, sisters, daughters). For comparison, the model also estimated 5-year and lifetime risk for a woman of the same age and race/ethnicity at average risk. High-risk thresholds were defined as ≥1.67% for 5-year risk and ≥20.0% for lifetime risk. Self-perceived skin tone was recorded on a 6-point scale (1 = lightest, 6 = darkest), adjusted to the puerto rican population. Logistic regression models were used to assess associations between skin tone and high-risk classification, adjusting for age, education, income, and family history. Results: The mean 5-year risk score was 1.73% (SD = 1.39), and the mean lifetime risk score was 11.57% (SD = 9.86). Overall, 41.1% of participants met the 5-year high-risk threshold, and 8.22% met the lifetime high-risk threshold. Participants who perceived themselves as having a darker skin tone had slightly higher average 5-year breast cancer risk scores (2.01% vs. 1.68%) and lifetime risk scores (11.85% vs. 11.53%) compared to lighter-skinned counterparts. In adjusted logistic regression models, perceived skin tone was not significantly associated with 5-year high-risk classification (OR = 0.95; 95% CI 0.56, 1.54; p = 0.835). For lifetime high risk, each one-unit increase in perceived skin tone was associated with 63% higher odds of high-risk classification, though this was not statistically significant (OR = 1.63; 95% CI 0.65, 4.57; p = 0.296). Conclusion: This study supports the need for improved, culturally relevant breast cancer risk models that more accurately reflect the heterogeneity of Hispanic/Latina populations, including Caribbean women. Funding: This project was founded by Cancer Prevention and Control (CAPAC) and supported by Award Number R25MD007607 from the National Institute on Minority Health and Health Disparities. Citation Format: Desire Vázquez-Ortiz, Brenda J. González, Nancy R. Cardona-Cordero. Invasive breast cancer risk scores among Caribbean women within a 5-year period and up to age 90 (lifetime risk): A case-control study in Puerto Rico abstract. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr C027.
Vázquez-Ortiz et al. (Thu,) studied this question.