Electrical potential measurements in human breast cancer and benign lesions.

Electrical potentials were measured on the breast and at other sites in 110 women with palpable breast masses. The tumor site was significantly electropositive compared with control sites only when the tumor was a cancer, as determined by a subsequent biopsy; the electrical potentials were not influenced by age or menstrual cycle. The results indicate that, on average, altered electrical potentials detected by a noninvasive measurement on the skin reflect the presence of transformed cells in patients with breast cancer. Previous in vitro studies of breast tissue and breast epithelial cells suggest that the observed effect was due to a change in interstitial K+ concentration that arose from alterations in the activity of K+ channels. Electrical potentials may be suitable for diagnosis of individual patients if refinements are made in the measurement technique.