A machine that takes electrical measurements on a person's skin could help to determine whether underlying breast lumps are cancerous or benign, possibly eliminating the need for thousands of surgical biopsies each year.
Doctors in a European study are reporting today that the device reliably ruled out cancer in tumors that were large enough to be felt in a physical examination. Benign tumors often can be left alone because they do not pose a significant health risk.
In a 40-minute procedure, nurses attach a series of probes -- or sensors -- to the surface of the breast. The sensors are connected by wire to a laptop computer that measures the electrical activity in the underlying tissue.
Scientists have learned that cancerous and normal cells emit different signals, and the differences are measurable on the skin's surface. The device is made by Biofield Corp. of Roswell, Ga.
"It's an EKG of the breast," said Dr. Neil B. Friedman of Mercy Medical Center in Baltimore, referring to electrocardiograms, which measure abnormalities in a person's heart rhythm. "We're really all like electric eels. We all have electrical activity going through our bodies."
Mercy is one of six medical centers involved in studies being conducted in the United States. Results of a separate European trial appear in today's issue of Lancet, a British medical journal.
European doctors testing the electrical-sensing machine enrolled 661 women who were scheduled for surgical biopsies. The doctors compared the biopsy findings with those of the machine.
The study found that the Biofield machine was useful in helping to diagnose larger tumors but less so in assessing smaller tumors that could not be felt. In the palpable tumors, the machine was correct 99 percent of the time when its measurements indicated the absence of cancer.
Each year, more than 180,000 women in the United States and 170,000 in Europe are diagnosed with breast cancer. Many more discover suspicious lumps as a result of physical examination or routine mammograms.
Doctors rely on biopsies to diagnose the lumps, and more than 80 percent of the biopsies find benign tissue. Even if the Biofield device effectively diagnoses tumors, doctors say, it must be used in conjunction with mammograms in making the final assessment.
"At this point in time, this is not going to replace mammography," said Friedman, director of breast services at Mercy.
Biofield hopes to begin selling the device in Europe this year but must perform an additional study in the United States before asking the U.S. Food and Drug Administration for permission to sell the machine in this country.
Dr. William C. Dooley, director of the Johns Hopkins Breast Center, said doctors have recently found nonsurgical ways to perform biopsies that have made the Biofield system less attractive as a diagnostic tool. The techniques involve the use of needles to draw tissue out of the breast.
Such biopsies can be done for about $70, which he said will probably be competitive with the Biofield procedure.
Dooley said the device would be much more attractive as a means of screening women who are at risk because of family history. The device has not been tested under those conditions.
In another development, scientists at the University of Maryland School of Medicine say they have identified a mechanism that causes abnormal copies of breast DNA to be made, setting in motion the growth of malignant tumors.
The scientists also identified a defective protein that can serve as a marker that DNA replication has gone awry. They studied 25 tumors known to be cancerous and found an abnormal version of the protein -- called proliferating cell nuclear antigen -- in all of the specimens.
If a streamlined test for the protein can be found, it could be used to make biopsies more accurate, especially in "gray areas" where current tests have trouble telling whether cells are cancerous or benign.
"What this test would do is remove the gray," said Dr. Robert J. dTC Hickey, an associate professor of pharmacology and senior author of a paper appearing in the August edition of the journal Cancer Research.
Pub Date: 8/01/98