Kinetics of Troponin and BNP in Breast Cancer Chemotherapy With Adriamycin and Trastuzumab

This pilot study involves very frequent monitoring of breast cancer patient blood levels of hs-cTnT Troponin and n-t-BNP (Brain Natriuretic Peptide) before and after initiation of chemotherapy with either adriamycin or trastuzumab in order to define the kinetics of both biomarkers during the first two cycles of chemotherapy. Cardiac troponins and BNP are frequently elevated after experimental chemotherapy in animal models. Their behavior in humans has been inconsistent, with occasional elevations seen, usually within 30 days of therapy. Assays for troponin with sensitivity into the pg/ml range have now been introduced. A majority of patients greater than age 50 have elevations above the detection limit, compared to only 1-3% with conventional troponin assays, and over 90% of diabetics have elevations above the detection limit. Moreover, augmented release of high sensitivity troponin is detected after exercise or rapid atrial pacing of durations of 10-15 minutes in patients with and without coronary artery disease. This improved sensitivity suggests the potential for detection and monitoring of cardiac damage after cancer chemotherapy. We hypothesized that this new generation of troponin assay would be associated with kinetic behavior suggesting ongoing cardiac damage with anthracycline therapy, and possibly also with trastuzumab.