Abstract P2-08-26: Cardiovascular events and mortality in a population-based cohort treated for ductal carcinoma in situ

Abstract

Abstract Background: Ductal carcinoma in situ (DCIS) patients are mostly diagnosed through cancer screening programs, suggesting that this population may have a healthy screenee effect of being more health-conscious, have lower comorbidity and belong to a higher socio-economic class. In this population-based cohort, we assessed the likelihood of cardiovascular events and mortality in DCIS patients, comparing with a control group of non-DCIS patients. Methods: Using the Korean National Health Insurance Service database, 13,740 women who were diagnosed of DCIS between 2007 and 2013 were analyzed. Control group matched by age was selected three times the number of DCIS cases (n=41,200). Follow-up for comorbidities and survival was performed up to 2016. Cox proportional hazard regression analysis was used to evaluate the association between DCIS and myocardial infarction (MI) risk, cerebrovascular stroke risk and mortality rate. The DCIS group was divided into pure DCIS patients and DCIS patients with subsequent invasive breast cancer for analysis. Results: Compared to the control group, patients with DCIS history were more likely to have hypertension, diabetes mellitus, dyslipidemia and the Charlson’s Comorbidity Index score was significantly higher. Patients with DCIS history also had higher income and were more likely to live in urban districts. Despite of higher comorbidity rate, pure DCIS patients had a trend of lower MI risk (HR 0.710; 95% CI 0.448 - 1.125) and significantly lower stroke risk (HR 0.708; 95% CI 0.492 - 1.019). Whereas, DCIS patients with subsequent invasive breast cancer had a significantly lower MI risk (HR 0.582; 95% CI, 0.371 - 0.913) and trend of lower stroke risk (HR 0.815; 95% CI 0.610 - 1.108). Mortality rate was similar between control group and pure DCIS patients, but was higher in DCIS patients with subsequent invasive breast cancer (HR 1.629; 95% CI 1.339 - 1.983). The trend of lower risk for cardiovascular events was sustained when adjusting for age, income and comorbidities (hypertension, diabetes mellitus and dyslipidemia). Conclusion: DCIS patients had a lower risk for MI and stroke compared to the control group despite of higher rate of comorbidities, which may reflect socioeconomic differences. DCIS patients with subsequent invasive breast cancer had higher mortality rate, whereas pure DCIS patients had similar survival rate compared to the control group. Citation Format: Tae-Kyung Yoo, Byung Joo Chae, Kyung Do Han, DaHye Kim, Juneyoung Ahn, Woo-Chan Park, Se Jeong Oh. Cardiovascular events and mortality in a population-based cohort treated for ductal carcinoma in situ [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-26.