N-terminal pro-brain natriuretic peptide levels after receipt of anthracycline for breast cancer.

Abstract

e24103 Background: Many of the 200,000 patients diagnosed with breast cancer (BC) annually in the United States receive anthracycline-based therapy, increasing their risk of future congestive heart failure. N-terminal brain natriuretic peptide (NT-proBNP) has been used as a biomarker of asymptomatic cardiac dysfunction in the general population and is of interest to identify patients who might benefit from echocardiography during survivorship. This study aimed to assess how age, baseline comorbidities, and time since BC diagnosis impact NT-proBNP levels after anthracycline-based chemotherapy. Methods: This retrospective study, using samples collected in our ongoing prospective Mayo Clinic Breast Disease Registry, included 20 survivors of non-metastatic BC patients per year for each of the first 5 years after anthracycline-based chemotherapy (n=100 total). NT-pro-BNP levels were assessed using a Roche immunoassay. Cardiac risk factors were obtained by chart review. Multivariable linear regression models assessed associations between NT-proBNP values and these independent variables: baseline cardiac risk factors (including hypertension, hyperlipidemia, obesity, diabetes mellitus, and smoking), tumor ER status (surrogate for possible endocrine therapy), time between diagnosis and serum collection, T and N status, use of trastuzumab, and age. Results: The mean age at the time of BC diagnosis was 52.2 (SD 9.8). 13% of tumors were human epidermal growth factor receptor (HER2)-positive and 71% were estrogen receptor (ER) positive. NT-proBNP was elevated in 34%. Mean NT-BNP level was higher (p=0.047) for those in years 4-5 (158 pg/mL) compared to those in years 1-3 (106 pg/mL) (See Table.) Models revealed years from diagnosis to serum draw (p=0.026), older age (p=0.006), more cardiac risk factors (p=0.064), and N2-3 (p=0.001) were associated with elevated NT-pro-BNP level. Use of trastuzumab, ER status, and tumor size were not associated with NT-proBNP. Conclusions: NT-proBNP is elevated in 1/3 of survivors who received anthracycline therapy for BC. As expected, cardiac risk factors and advancing age are associated with higher NT-proBNP. NT-proBNP values >300 were only found in patients who were 4-5 years after diagnosis. Additional research will be needed to further define the diagnostic and prognostic merit of NT-proBNP in survivors after receipt of anthracycline therapy. [Table: see text]