Nicole T Gordon1,2, Jaime J Alberty-Oller3, Kezhen Fei4,5, Giampaolo Greco4,5, Emily J Gallagher3,6,7, Derek LeRoith3,6,7, Sheldon M Feldman8, Bridgid Killilea9, Susan K Boolbol10, Lydia Choi11, Neil Friedman12, Melissa Pilewskie13, Elisa Port3, Amy Tiersten3,14, Nina A Bickell3,7. 1. Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute at Mount Sinai, New York, NY, USA. ngordon@cbccusa.com. 2. , Bakersfield, CA, USA. ngordon@cbccusa.com. 3. Icahn School of Medicine at Mount Sinai, Tisch Cancer Institute at Mount Sinai, New York, NY, USA. 4. Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, Center for Health Equity and Community Engaged Research, New York, NY, USA. 5. Center for Health Equity and Community Engaged Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA. 6. Division of Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA. 7. Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA. 8. Department of Surgery, Montefiore Medical Center, New York, NY, USA. 9. Department of Surgery, Yale School of Medicine, New Haven, CT, USA. 10. Department of Surgery, Mount Sinai Beth Israel, New York, NY, USA. 11. Department of Surgery, Wayne State University School of Medicine, Detroit, MI, USA. 12. Department of Surgery, Mercy Medical Center, Baltimore, MD, USA. 13. Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, USA. 14. Department of Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Abstract
BACKGROUND: Black women with breast cancer have a worse overall survival compared with White women; however, no difference in Oncotype DX™ (ODX) recurrence scores has been observed to explain this health disparity. Black women are also disproportionately affected by insulin resistance. We evaluated whether insulin resistance is associated with a higher ODX recurrence score and whether there is a difference between White and Black women to explain disparate clinical outcomes. METHODS: A subgroup analysis of patients in a multi-institutional cross-sectional study evaluating differences in insulin resistance between White and Black women was performed. Women diagnosed with a new hormone receptor-positive, HER2/neu-negative breast cancer with an ODX recurrence score were identified. Fasting blood glucose and insulin measurements were used to calculate the homeostatic model assessment of insulin resistance (HOMA-IR) score, a method for assessing insulin resistance, and compared against ODX scores. RESULTS: Overall, 412 women (358 White women, 54 Black women) were identified. Compared with White women, Black women had a higher body mass index (30 vs. 26 kg/m2, p < 0.0001), higher HOMA-IR score (2.4 vs. 1.4, p = 0.004), and more high-grade tumors (30% vs. 16%, p = 0.01). There was a direct positive association with an increasing ODX score and HOMA-IR (p = 0.014). On subset analysis, this relationship was seen in White women (p = 0.005), but not in Black women (p = 0.55). CONCLUSION: In women with newly diagnosed breast cancer, increasing insulin resistance is associated with a higher recurrence score; however, this association was not present in Black women. This lack of association may be due to the small number of Black women in the cohort, or possibly a reflection of a different biological disease process of the patient's tumor.
BACKGROUND: Black women with breast cancer have a worse overall survival compared with White women; however, no difference in Oncotype DX™ (ODX) recurrence scores has been observed to explain this health disparity. Black women are also disproportionately affected by insulin resistance. We evaluated whether insulin resistance is associated with a higher ODX recurrence score and whether there is a difference between White and Black women to explain disparate clinical outcomes. METHODS: A subgroup analysis of patients in a multi-institutional cross-sectional study evaluating differences in insulin resistance between White and Black women was performed. Women diagnosed with a new hormone receptor-positive, HER2/neu-negative breast cancer with an ODX recurrence score were identified. Fasting blood glucose and insulin measurements were used to calculate the homeostatic model assessment of insulin resistance (HOMA-IR) score, a method for assessing insulin resistance, and compared against ODX scores. RESULTS: Overall, 412 women (358 White women, 54 Black women) were identified. Compared with White women, Black women had a higher body mass index (30 vs. 26 kg/m2, p < 0.0001), higher HOMA-IR score (2.4 vs. 1.4, p = 0.004), and more high-grade tumors (30% vs. 16%, p = 0.01). There was a direct positive association with an increasing ODX score and HOMA-IR (p = 0.014). On subset analysis, this relationship was seen in White women (p = 0.005), but not in Black women (p = 0.55). CONCLUSION: In women with newly diagnosed breast cancer, increasing insulin resistance is associated with a higher recurrence score; however, this association was not present in Black women. This lack of association may be due to the small number of Black women in the cohort, or possibly a reflection of a different biological disease process of the patient's tumor.