Abstract 2194: Association of metabolic syndrome conditions with risk of second primary cancer of any organ in breast cancer survivors

Abstract

Abstract Purpose: Breast cancer survivors are at increased risk of developing second primary cancers; however, factors attributing to increased risk of second primary cancer in breast cancer survivors are under-studied. We evaluated the association of metabolic syndrome conditions with second primary cancer of any organ in breast cancer survivors. Methods: In this retrospective cohort study, we included 37,222 patients diagnosed with breast cancer between 2008-2020 at Kaiser Permanente Southern California (KPSC), an integrated healthcare system. We extracted data on cancer-related variables, sociodemographic and clinical variables from KPSC’s cancer registry and electronic health records. Among the metabolic conditions, we identified diabetes, hypertension, and dyslipidemia using ICD-10 diagnosis codes at or 1-year prior to breast cancer diagnosis; obesity was based on body mass index (BMI≥30kg/m2). We included metabolic syndrome as a categorical variable: 0, 1-2, and 3+ metabolic conditions. We followed patients electronically from breast cancer diagnosis until patients developed second primary cancer of any organ, died, disenrolled from the health plan, or reached study’s end (12/31/2021), whichever occurred first. Proportional hazards regression was used to report association [HR (95%CI)] between metabolic conditions and any second primary cancer. Results: During a median (IQR) follow-up of 5.17 (2.75-8.58) years, 1701 (4.6%) patients developed any second primary cancer. More than half (53.1%) of the breast cancer survivors had 1-2 metabolic conditions at baseline; 19.4% had 3+ metabolic conditions, and the rest 27.5% did not have any metabolic condition. Hypertension was the most common metabolic condition (45.5%), followed by obesity (38.9%), dyslipidemia (36.5%), and diabetes (19.0%). Survivors with 0 and 1-2 metabolic conditions were 35% and 19% less likely to develop any second primary cancer than survivors with 3+ metabolic conditions, respectively [crude HR (95%CI): 0.65 (0.57-0.75) and 0.81 (0.72-0.91), respectively]. Reduced risk in survivors with 1-2 metabolic conditions persisted adjusting for age, race and ethnicity, breast cancer diagnosis year, breast tumor SEER summary stage, breast tumor estrogen-progesterone status, smoking status, and breast tumor treatment [adjusted HR (95%CI): 0.87 (0.77-0.99)]. Conclusion: Risk of second primary cancer of any organ was elevated in breast cancer survivors with three or more metabolic conditions. Citation Format: Amrita Mukherjee, Zheng Gu, Lie Hong Chen, Arnold L. Potosky, Reina Haque. Association of metabolic syndrome conditions with risk of second primary cancer of any organ in breast cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2194.