RESUMO
PURPOSE: To correlate the Cole relaxation frequencies obtained from measurements of the electrical properties of breast tissue to the presence or absence of cancer. METHODS: Four-lead impedance measurements were obtained on ex vivo specimens extracted during surgery from 187 volunteer patients. Data were acquired with a commercial Solartron impedance bridge employing 4-lead Ag-AgCl or blackened platinum (BPt) electrodes at frequencies logarithmically spaced from 1 Hz to 3.2 × 10(7) Hz utilizing 6-10 frequencies per decade. The Cole frequencies obtained from these measurements were correlated with the tissue health status (cancer or noncancer) obtained from histological analysis of the specimens. RESULTS: Analysis of the impedance measurements showed that the Cole relaxation frequencies correlated to the presence or absence of cancer in the examined tissue with a sensitivity up to 100% (95% CI, 99%-100%) and a specificity up to 85% (95% CI, 79%-91%) based on the ROC curve of the data with the Cole frequency as the classifier. CONCLUSIONS: The results show that the Cole frequency alone is a viable classifier for malignant breast anomalies. Results of the current work are consistent with recent bioimpedance measurements on single cell and cell suspension breast cell lines.