New research presented at the 93rd annual meeting of the American Association for Cancer Research (AACR) suggests that monitoring with the serum HER2/neu oncoprotein test may help oncologists assess the effect of trastuzumab(Drug information on trastuzumab) (Herceptin)-based therapy in patients with metastatic breast cancer. These data add to the growing body of evidence supporting the value of the serum HER2/neu oncoprotein test in the management of patients with metastatic breast cancer.
Serum monitoring provides a "real time" picture of a woman’s changing HER2/neu levels, enabling oncologists to evaluate the effectiveness of a particular therapy. Studies have shown that decreasing HER2/neu values reflect response to therapy, while increasing values may indicate progressive disease.
Data from the study supported the value of the serum HER2/neu oncoprotein test in early prediction of response to trastuzumab-based therapy in metastatic breast cancer patients. Trastuzumab works by targeting cancer cells that overexpress the HER2 protein, and slowing or stopping the growth of these cells.
The study was designed to examine whether serial monitoring of serum HER2/neu levels in metastatic breast cancer patients can predict or parallel response to therapy. A total of 3,122 serum samples were taken from 75 women at baseline, and again immediately prior to each infusion of trastuzumab. A decline in serum HER2/neu levels over time correlated to response to trastuzumab. Specifically, the ratio of baseline serum levels to the levels monitored throughout the course of treatment was significantly higher among patients responsive to therapy than among those who did not respond (P ≤ .01). This predictive value was apparent after the first infusion of trastuzumab.
"These data suggest that monitoring with this oncoprotein blood test can help physicians treat their metastatic breast cancer patients," said Dr. Wolfgang Johannes Köstler, clinical division of oncology, department of internal medicine at University Hospital in Vienna. "In addition to the health implications, optimizing treatment may also have a positive impact on cost."