By Merritt McKinney

NEW YORK, Mar 08 (Reuters Health) - A type of imaging called positron emission tomography (PET) may be more accurate than conventional techniques for evaluating women who have been treated for http://www.reutershealth.com/wellconnected/doc06.htmlbreast cancer, California researchers report.

"PET will be more accurate than conventional imaging to tell women whether the disease has returned or is still in remission," the study's lead author, Dr. Johannes Czernin of the University of California, Los Angeles, told Reuters Health.

The importance of this and other studies that demonstrate the benefits of PET, Czernin said, is underscored by the recent announcement that Medicare will cover the cost of the imaging for women who have been treated for breast cancer.

Once a woman is treated for breast cancer, she regularly undergoes several types of imaging tests to make sure that her cancer has not returned. These tests include mammography, CT scans, magnetic resonance imaging (MRI) and ultrasound.

The type of PET used in the study, known as FDG PET, works by measuring the use of glucose, or sugar, in the body's cells. Since cancer cells consume more sugar than normal cells, the scan identifies cancerous cells and shows whether they have spread beyond the original location of the tumor.

Several studies have shown that FDG PET, a full-body scan, is more effective than conventional tests for telling whether breast cancer has spread, or metastasized. But whether PET is a useful tool for predicting a woman's prognosis after treatment for breast cancer has been uncertain.

Czernin and his colleagues studied 61 women who had undergone both PET and a combination of conventional imaging tests after being treated for breast cancer. The women were followed for at least 6 months.

PET was more accurate than conventional imaging for both detecting and ruling out cancer recurrence, the researchers report in the March issue of the Journal of Nuclear Medicine.

The results of PET and conventional imaging were in agreement for 75% of the women. In the remaining 25%, however, the techniques produced contradictory results. Nine women had positive results on PET, meaning that cancer had returned, but negative results on conventional imaging. PET was negative in six women who had positive results on conventional imaging.

Based on the women's outcome 6 months after testing, PET turned out to be correct in 12 of the 15 cases in which PET and conventional imaging produced conflicting results. Conventional imaging was correct in only 3 of the 15 women.

"You get better information from a PET scan than from the combined information derived from many other tests," Czernin said.

In the report, the investigators note that the point at which cancer recurrence is detected can affect treatment choices. If cancer is found before it spreads beyond the breast, surgery or radiation may be effective. Once cancer metastasizes, however, chemotherapy, radiation or both are usually needed.

Right now, PET imaging is "vastly under-utilized," according to Czernin. But the number of women with breast cancer who are having PET is "increasing dramatically," he said.

The scan might also be useful for detecting breast cancer the first time around, according to Czernin. One possible use of PET, he said, might be in detecting cancer in women for whom mammograms are relatively less effective--such as those with very dense breast tissue or those with scars or implants.

SOURCE: Journal of Nuclear Medicine 2002;43:325-329.

Saliva test to detect breast cancer under development

March 8, 2002

By Kathleen Doheny

SAN DIEGO, California (Reuters Health) - A simple and inexpensive saliva test may detect breast cancer in its early stages, according to US researchers who have studied the approach for 5 years.

The test, which is being developed commercially by a Wisconsin company, identifies and measures the levels of the tumor marker HER2/neu in a woman's saliva. HER2/neu elevation strongly suggests the presence of breast cancer, according to Dr. Charles F. Streckfus of the University of Mississippi Medical Center in Jackson, who will present the findings Saturday at the International Association for Dental Research annual meeting in San Diego.

Working on what Dr. Streckfus calls an "educated hunch," his team isolated a soluble salivary form of the HER2/neu protein. They then evaluated more than 125 patients--including some with breast cancer, some with benign tumors, and some healthy controls patients--and found that elevated saliva levels of HER2/neu correlated with breast malignancies in 87% of cases.

High levels of the marker in saliva also correlate with high levels in the bloodstream, Dr. Streckfus said.

About 1100 patients are now enrolled in advanced-stage clinical trials of the test, according to John Wundrock, president and CEO of MedicGroup in Jackson, Wisconsin, which is developing two commercial versions of the saliva test.

MedicGroup hopes to apply to the US Food and Drug Administration for approval for both tests by year's end and to have both on the market by the end of 2003. The test is expected to be inexpensive, but exact costs are yet to be determined.

The saliva tests are seen by the developers as a supplement to physical examination and mammography. Besides aiding in breast cancer detection, the test could also potentially help doctors monitor treatment and perform follow-up screening, Dr. Streckfus said.

Source: www.reutershealth.com