Purpose: To evaluate the cardiovascular risk profile of a subset of patients with early-stage breast cancer treated with adjuvant taxane-anthracycline-containing chemotherapy and/or trastuzumab (Herceptin).
Experimental design: Twenty-six patients with breast cancer (mean, 20 months postchemotherapy) and 10 healthy age-matched women were studied. We measured 14 metabolic and vascular established cardiovascular disease (CVD) risk factors, body mass index, cardiorespiratory fitness, and left ventricular systolic function. All assessments were done within a 14-day period.
Results: Cardiac abnormalities were suggested by left ventricular ejection fraction (LVEF) <50% in 8% of patients, LVEF remained >10% below pretreatment values in 38%, whereas 50% presented with resting sinus tachycardia. Brain natriuretic peptide was significantly elevated in 40% of patients and was correlated with LVEF (r = -0.72, P =or< 0.001). For the majority of CVD risk factors, similar proportions of patients and controls (35-60%) were classified as "undesirable." A significantly higher proportion of patients were classified with low cardiorespiratory fitness (46% versus 0%, P < 0.01), being overweight/obese (72% versus 50%, P < 0.05), and having resting sinus tachycardia (50% versus 0%, P < 0.01) compared with controls. Cardiorespiratory fitness and body mass index were correlated with CVD risk factors (r = -0.64 to 0.63, P < 0.05; r = -0.63 to 0.67, P < 0.05, respectively). Exploratory analyses revealed several differences between CVD risk factors based on chemotherapy regimen.
Conclusion: Breast cancer survivors treated with adjuvant chemotherapy are at a higher risk of developing late-occurring CVD than age-matched controls due to direct and indirect treatment-related toxicity.