Introduction:
Cardiotoxicity is a well-known risk in breast cancer patients treated with anthracyclines and trastuzumab. Ezaz et al. developed a clinical risk score (CRS) to risk stratify these patients. Despite evidence that African American (AA) race is a significant risk factor for cardiotoxicity, no study has assessed the impact of AA race on this CRS. Here we assess the discrimination ability of the Ezaz et al. CRS with the addition of AA race.
Methods:
This is a retrospective cohort utilizing a registry of 118 patients with stage I-IV breast cancer treated with anthracyclines and/or trastuzumab. Patients without baseline echocardiography data or with baseline LVEF < 50% were excluded. The CRS from Ezaz et al. consisting of age, adjuvant chemotherapy, coronary artery disease, atrial fibrillation or flutter, diabetes mellitus, hypertension, and renal failure was calculated with the addition of AA race. Cardiotoxicity was defined by an LVEF decline of ≥ 10% to LVEF < 53% from baseline.
Results:
In our 118 patient cohort, the mean age was 59 years, 23 (20%) AA patients, 65 (55%) patients considered low risk (scores of 0-3) and 53 (45%) considered moderate to high risk (scores ≥4). After a follow up of 3 months to 5 years, 14 (12%) patients developed cardiotoxicity.
Table 1
lists the CRS changes in statistical characteristics and predictability with the addition of AA race. In comparing the models, the AUC c-statistic increased from 0.609 to 0.642 (95% CI 0.47-0.75, 95% CI 0.49-0.79 respectively; P value = 0.56) with the addition of AA race (
Figure 1
).
Conclusions:
In this study, the Ezaz et al. CRS demonstrated improved discrimination and sensitivity with the addition of AA race. This study suggests AA race improves the predictive ability of the Ezaz et al. CRS. Given the limited size of our study, we promote that this should be hypothesis-driving and encourage further investigation on the path to develop an important risk stratification tool.
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