Estimating Renal Insufficiency in Breast Cancer Patients Using Ultrasound Determined Resistive Index: A Cross‑Sectional Study of a Nigerian Cohort

Purpose: The purpose of this study was to investigate if the renal arterial resistive index (RRI) is impaired in women with breast cancer and correlate these values with estimated glomerular filtration rate (eGFR) as determined by the Chronic Kidney Disease Epidemiology Collaboration equation. Materials and Methods: This was an observational study of fifty chemotherapy‑naïve women with histologically confirmed breast carcinoma recruited consecutively over a 1‑year period. All women had a Doppler ultrasonography done to determine their RRI and eGFR. Results: Fifty women with breast cancer were evaluated. Their ages ranged from 28 to 85 years, with a mean age of 48.6 ± 13.8 years. The mean RRI in the study was 0.7 ± 0.07. There were thirty subjects (60%) with abnormal resistive index (RI) (>0.7), whereas twenty subjects (40%) had normal RRI. The mean eGFR in the study cohort was 62.6 ± 17. eGFR was abnormal in 96% of the women. About half (n = 24, 48%) had severe renal insufficiency (stages 3 and 4). The majority had advanced breast disease (stages 3 and 4), with 23 patients (46%) presenting with stage 3 disease and 17 (34%) stage 4 disease. Pearson’s correlation done between RRI and eGFR showed a mild but statistically significant correlation between RI and eGFR (r = −0.28, P = 0.04). Conclusions: Renal artery RI is raised in most subjects with breast cancer and correlates significantly with the eGFR as determined by cystatin C alone.