Abstract P1-13-02: Dynamic changes in high-sensitivity cardiac troponin I in response to anthracycline-based chemotherapy-The Cardiac Care Trial pilot data

Abstract

Abstract BACKGROUND Treatment advances have improved cancer-related outcomes and shifted interest towards minimising long-term iatrogenic complications, particularly chemotherapy-related cardiotoxicity. High-sensitivity cardiac troponin I (hs-cTnI) assays accurately quantify very low concentrations of plasma troponin and enable early detection of cardiomyocyte injury prior to development of myocardial dysfunction. The profile of hs-cTnI in response to anthracycline-based treatment has not previously been described. PATIENTS AND METHODS This was a multi-centre prospective observational cohort study. Female patients with newly-diagnosed invasive breast cancer scheduled to receive adjuvant or neo-adjuvant anthracycline-based (epirubicin) chemotherapy were recruited. Blood sampling was performed before, during and 24 hours after each treatment cycle. Plasma hs-cTnI concentrations were measured using the Abbott ARCHITECTSTAT assay (limit of detection 1.2 ng/L, coefficient of variation ≤10% at 4.7 ng/L, 99th centile upper reference limit in women 16 ng/L). RESULTS We recruited 78 women with a mean (standard deviation) age of 53.6 (9.6). The median (IQR) baseline troponin concentration was 1 (1 to 4) ng/L and median (IQR) cumulative epirubicin dose was 394 (300 to 405) mg/m2. Following an initial 33% fall 24 hours following anthracycline dosing (p <0.001), hs-cTnI concentrations increased by a median of 50% (p<0.001) with each successive treatment cycle. In total, 45 patients had troponin measured immediately prior to the sixth treatment cycle of whom 21 (46.6%) had hs-cTnI concentrations ≥16 ng/L indicating myocardial injury. Plasma hs-cTnI concentrations prior to the second treatment cycle were a strong predictor of subsequent myocardial injury. CONCLUSIONS Cardiotoxicity arising from anthracycline therapy is detectable in the earliest stages of breast cancer treatment and is cumulative with each treatment cycle. More than one third of patients will develop biochemical evidence of chronic myocardial injury with plasma hs-cTnI concentrations above the 99th centile upper reference limit. This injury is most reliably determined from blood sampling performed before rather than during or after each treatment cycle. Citation Format: Olga Oikonomidou, Evangelos Tzolos, Philip D Adamson, Peter S Hall, Iain R MacPherson, Morag MacLean, Steff Lewis, Heather McVicars, David E Newby, Nicholas L Mills, Ninian Lang, Peter A Henriksen. Dynamic changes in high-sensitivity cardiac troponin I in response to anthracycline-based chemotherapy-The Cardiac Care Trial pilot data [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-13-02.