Abstract P4-10-09: The impact of Charlson comorbidity index on survival of triple negative breast cancer

Abstract

Abstract Background Patients with cancer and comorbidities have been found to have poorer survival since they may be unable to receive or complete treatments. It is not clear if comorbid conditions impact survival of patients in all stages of disease and all ER/PR/HER2 subtypes. Purpose The purpose of this study was to determine how the Charlson Comorbidity Index (CCI) affected the risk of mortality of triple negative breast cancer (TNBC) within each stage of disease. Methods We accessed 22,503 cases of TNBC and documented CCI from the California Cancer Registry 2000-2015. The CCI is a weighted index based on the presence of certain comorbid conditions twelve months prior through six months following the cancer diagnosis and weighted by the severity of those conditions. A score of 0 is interpreted as no significant comorbidity burden and scores of 3 or more are generally interpreted as a high comorbidity burden. Kaplan-Meier Survival Analysis and the Log Rank test were used to compare differences in breast cancer specific survival between patients with a CCI of 1, 2 or higher (2+) versus a CCI of 0. Cox Regression Analysis was used to estimate risk of mortality of CCI after adjusting for age, race/ethnicity, socioeconomic status, grade, and treatment. Analyses were conducted separately for each stage. Hazard ratios and 95% confidence intervals (CIs) were reported. Results There 16,664 (74.1%) cases with a CCI of 0; 3,915 (17.4%) with a CCI of 1; 1,055 (4.7%) had a CCI of 2, and the remaining 869 (3.9%) cases of TNBC had a CCI of 3 or higher. Unadjusted survival analysis indicated that for stages 2 and 3, there was increased survival with decreasing CCI score. For stages 1 and 4, survival was only better for patients with a CCI of 0 versus a CCI of 2+. Cox regression analysis indicated that the CCI made no difference in risk of mortality for patients with stage 1 disease. Patients with a CCI of 2+ had an increased risk of mortality when compared with a CCI of 0 for stage 2 (HR = 1.48, CI: 1.25-1.77), stage 3 (HR=1.25, CI: 1.03-1.52) and stage 4 (HR = 1.53; CI: 1.22-1.92). Conclusion Comorbidity as measured by the CCI does not increase the risk of mortality for patients with stage 1 TNBC and only increases risk of mortality in higher stages for patients with a CCI score of 2 or higher. Citation Format: Parise C, Caggiano V. The impact of Charlson comorbidity index on survival of triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-10-09.