Abstract P6-06-09: Baseline assessment of left ventricular function for breast cancer patients undergoing anthracycline and/or trastuzumab: What is the prevalence of baseline dysfunction?
Authors: Abu-Khalaf MM , Medic I , Hatzis C , Park E , Chung G , DiGiovanna M , Hofstatter E , Sanft T , Pusztai L , Gross C , Russell K , Russell R 
Published: August 2014

Background: It is unclear if all breast cancer patients require baseline left ventricular function (LVEF) assessment prior to anthracycline chemotherapy, and the approach is variable in clinical practice. While some oncologist do not obtain baseline LVEF assessment in breast cancer patients under the age of 65 without known cardiac risk factors, others continue to perform baseline LVEF assessment in all breast cancer patients who will be receiving adjuvant anthracycline chemotherapy. We sought to determine the prevalence of left ventricular dysfunction in breast cancer patients prior to anthracycline and /or trastuzumab therapy, and to identify the cardiac risk factors associated with a low LVEF.

Methods: We performed a retrospective analysis of the Yale Equilibrium Radionuclide Angiography (ERNA) database, which also included self-reported cardiac risk factors. We identified 702 patients who had a baseline ERNA scan prior to anthracycline and/or trastuzumab therapy for an initial diagnosis of stages I-IV BC between July 2003 and May 2013. Our objective was to determine the prevalence rate of an abnormal baseline LVEF defined as &lt;50%, and determine if age, BMI, known coronary artery disease (CAD) or pre-existing cardiac risk factors (hypertension (HTN), diabetes mellitus (DM), hyperlipidemia, smoking, obesity) increased the chance of having an abnormal baseline LVEF.

Results: Median age was 51(range 26-86); 637 (91%) patients were 65 years of age or younger. BMI &lt;25 in 271 (39%), 25-29 in 220 (31%), ≥30 in 197 (28%), and unknown in 14 (2%). Self-reported factors included HTN in 187 (22%), hyperlipidemia in 156 (22%), DM in 59 (8%), smoking history in 131 (19%), family history of cardiac disease in 337 (48%), known coronary artery disease in 13 (2%), and obesity(self reported) in 143 (20%) of patients. Of the 702 patients, only 14 (2%) had an LVEF &lt;50%. On univariate analyses, self-reported obesity had the only significant association with LVEF &lt; 50, p-value of 0.046 (Fisher's Exact test). There was no significant association between calculated BMI (&lt;30 vs. ≥30) and LVEF &lt;50. Multivariate logistic regression also showed self-reported obesity as having a significant association with an LVEF &lt;50 (p-value of 0.010, OR = 0.09, 95%CI 0.02 to 0.57). A family history of cardiac disease had a borderline significant association with an LVEF &lt;50 (p-value = 0.057, OR = 0.31, 95%CI 0.09 to 1.04).

Conclusion: The prevalence of abnormal baseline LVEF in patients being considered for anthracycline and/or trastuzumab therapy is small. Age, BMI, pre-existing cardiac risk factors and coronary artery disease were not associated with LVEF &lt;50. Future studies should focus on further risk stratification to identify patients with baseline low LVEF, and those at risk for declines in LVEF during and after anthracycline and/or trastuzumab therapy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-09.