my personal edition > breast cancer > news


  E-Mail this DGDispatch to a colleague

DGDispatch

New Technology Promises Simple Blood Test for Breast Cancer Detection: Presented at SABCS

By Coriene E. Hannapel

SAN ANTONIO, TX -- December 16, 2002 -- Protein chip mass spectrometry may be able to identify breast cancer-associated protein profile panels, which can lead to a simple blood test for cancer detection.

Lori L. Wilson, MD, Eastern Virginia Medical School, Norfolk, Virginia, United States, presented study results at the 25^th Annual Meeting of the San Antonio Breast Cancer Symposium.

While mammography remains the screening test of choice for breast cancer, Dr. Wilson said, this method fails to detect up to 20 percent of cancers.

"Currently, there are no single protein markers available for breast cancer screening," Dr. Wilson said. "Identification and analysis of a protein panel profile appears to have a greater potential for overcoming this limitation."

Dr. Wilson and colleagues at Eastern Virginia Medical School have used a procedure that combines SELDI (Surface Enhanced Laser Desorption Ionization)-TOF (Time of Flight) Protein Chip® (Ciphergen Biosystems, Inc., Fremont, California) Mass Spectrometry technology along with a classification algorithm to identify protein profiles for detection of breast cancer.

This innovative technology searches for multiple differentially expressed proteins and is able to create a protein profile panel.

With this procedure, a sample is placed directly on the chip, and proteins are then captured by affinity chemistry. An energy-absorbing molecule is added on the chip, which aids in the ionisation and desorption process, Dr. Wilson said. The proteins are then analysed by mass spectrometry, and the data analysis can be translated into either a trace view or a gel view.

Samples for this study were prospectively collected from patients enrolled through the Eastern Virginia Medical School Department of Surgery, Division of Surgical Oncology. The study population included pretreatment patients as well as normal healthy patients. Serum samples from139 females were analysed by SELDI technology.

Patients were classified as "normal," "benign" or "cancer." They ranged in age from 21 to 91 years, with a median age range of 46.5 years to 59.3 years. Caucasian and African-American women were included in the study. Eighty percent of study participants were found to have DCIS or early-stage I and II breast cancer.

The technology offers a number of surfaces available for protein capture, Dr. Wilson said. For this study, an IMAC-Cu chip was used and combined with a SAX chip. Nonspecific proteins were washed away with binding buffer, and the data analysis and peak labelling were performed with Wizard and Biomarker pattern software.

By combining the SAX chip along with the IMAC surface, it was hoped that improvements would result in resolution of the proteins and in the sensitivity and specificity. "For our learning set, we were actually very pleased that we improved our sensitivity/specificity to 96.6 percent for both, and our cross-validation was increased to 93.3 percent for sensitivity and specificity, and this was comparing cancers to normal," Dr. Wilson said.

Future direction for this procedure includes validation of initial classifiers in a large sample size study along with validation from outside institutions, Dr. Wilson added.

E-Mail this DGDispatch to a colleague

To print, use this version