The Cancer Detector LEC-03C is claimed to measure the speed with which cancer cells are reproduced. It is being promoted by the Leszlauer Electronic Research Laboratory, a company by Budapest, Hungary. The device was developed by Zoltán Leszlauer, who claims that it:
Analysis of Claims
Certain electrical properties of tumor cells differ from those of the normal tissues that surround them. Tumor cells demonstrate greater permittivity (ability to resist the formation of an electrical field) and conductivity of electrical current. These findings are thought to occur because (a) cancer cells tend to have higher sodium and water content than normal cells, and (b) their cell membranes have different electrochemical properties.
Electric current flowing through biological tissue encounters resistance (impedance) that can be measured. The higher the concentration of sodium, potassium, and other ions, the lower the resistance. Researchers believe that the scanners used in magnetic resonance imaging (MRI) could be used to detect such differences. In laboratory experiments, impedance measurements have been found to differ between tumors and normal tissues . One study, for example, found differences between surgically removed specimens of breast cancer and the surrounding normal tissue . The authors concluded that these findings might lead to the development of a noninvasive technique for early breast cancer detection. It is obvious, however, that surgical specimens differ from similar tissues in live patients, because temperature and blood flow alter impedance. Before concluding that impedance measurements are useful for detecting breast cancer, studies on human volunteers would have demonstrate reliability.
In addition, preliminary experiments in simulations (not actual patients) have found that electrical impedance tomography (EIT) could be helpful in detecting breast cancer. This technique—involving multiple measurements that “map” the measured values—searches for differences in skin impedance that might indicate a tumor in the underlying breast tissue . The Cancer Detector LEC-03C is a device at the end of a flexible tube. It does not use tomography but depends on sensors that—according to Leszlauer—are “placed on mucous membrane or on the open wound.” He states, however, that “the pus, chemicals, crust and keratoid layer” must be removed before the test is done.
No screening device is useful unless it produces accurate and consistent results. When I asked for Leszlauer for references to independent, controlled trials of his equipment, he replied that no clinical trial (or any other experiment) has been published or is being conducted. However, he stated that, “We have been making experiments with the equipment for 10 years and now we are sure that it works good.” 
The Bottom Line
Laboratory tests can find differences when carcinoma of the breast and colon , basal cell carcinoma , prostate cancer , and premalignant conditions such as Barrett ‘s esophagus  are compared to normal tissue in the laboratory. Practical application, however, seems unlikely. Detection in humans would require adjusting for differences in temperature, changes in local blood flow, and other factors. Furthermore, experiments have shown that nasal polyps  and tissue injury alter the sodium content and impedance of cells, which could significantly interfere with the accuracy of impedance screening. Even if these problems can be overcome, a tissue diagnosis would still be needed to determine appropriate therapy. And since the Cancer Detector LEC-03C involves pressing on the suspected areas of cancer, its use could increase the spread of cancer cells.
- Blad B, Baldetorp B. Impedance spectra of tumour tissue in comparison with normal tissue: A possible clinical application for electrical impedance tomography. Physiological Measurement 17 Suppl 4A:A105-115, 1996.
- Chauveau N and others. Ex vivo discrimination between normal and pathological tissues in human breast surgical biopsies using bioimpedance spectroscopy. Annals of the New York Academy of Sciences 873:42-50, 1999.
- Radai MM, Abboud S, Rosenfeld M. Evaluation of impedance technique for detecting breast carcinoma using a 2-D numerical model of the torso. Annals of the New York Academy of Sciences 873:360-369, 1999.
- Leszlauer Z. E-mail message to Christopher U. Lehmann, M.D., November 1, 1999.
- Soler AP and others. Increased tight junctional permeability is associated with the development of colon cancer. Carcinogenesis 20:1425-1431, 1999
- Emtestam L and others. Electrical impedance of nodular basal cell carcinoma: A pilot study. Dermatology 197:313-316, 1998.
- Lee BR and others. Bioimpedance: novel use of a minimally invasive technique for cancer localization in the intact prostate. Prostate 39:213-218, 1999.
- Gonzalez-Correa CA and others. Virtual biopsies in Barrett’s esophagus using an impedance probe. Annals of the New York Academy of Sciences 873:313-321, 1999.
- Bernstein JM and others. Nasal polyposis: immunohistochemistry and bioelectrical findings (a hypothesis for the development of nasal polyps). Journal of Allergy and Clinical Immunology 99:165-175, 1997.
Dr. Lehman, a neonatologist, is an assistant professor in the Department of Pediatrics of Johns Hopkins University Medical Center.
This article was posted on December 12, 1999.