Cancer Biomarkers Could Help Guide Treatment
New blood or biopsy tests predict patients' response to therapy, experts say
WEDNESDAY, April 18, 2007 (HealthDay News) -- New biomarkers could help doctors predict how individual cancer patients will respond to drug or radiation therapy, new research suggests,
The findings were detailed in a number of studies presented Wednesday at the annual meeting of the American Association for Cancer Research in Los Angeles.
Being able to determine how a patient will respond to specific cancer therapies should boost cancer treatment, experts said.
In one study, researchers at Lawrence Berkeley National Laboratory identified gene expression signatures that could serve as biomarkers to predict how a woman will respond to the breast cancer drugs lapatinib and CI-1040.
"Individuals respond differently to different therapeutics because there are substantial differences in the spectrum of genetic, biological and epigenetic (non-inherited) characteristics between breast cancers," Joe W. Gray, director of the Life Sciences Division at Lawrence Berkeley National Laboratory, explained in a prepared statement.
"We need better ways to identify how we can best tailor existing therapies to individuals and how to target experimental agents," Gray said.
In another study, French researchers said they found that mutations in the KRAS oncogene could predict a lack of response to the drug cetuximab in colorectal cancer patients. For people with this mutation, the drug is likely to be ineffective and could even harm them.
"Because of variety of different effective agents may now be available for any given type of cancer, deciding which treatment regimen is likely to be the most effective and the least toxic is more complicated than ever," Dr. Pierre Laurent-Puig, a professor of oncology at the University of Paris-Descartes, said in a prepared statement.
"Characterizing the factors that are predictive of toxicity and efficacy could lead to significant improvement in both the quality of treatment and outcomes," he said.
A third study by Vanderbilt University researchers identified 44 peptides (protein fragments) that can be used to determine response to tyrosine kinase inhibitor drug therapy -- combined with radiation therapy -- in patients battling lung or brain cancer.
"It is difficult to assess the response of cancer in the brain or lung to treatment, since those neoplasms [tumors] are difficult to access safely. With the proper biomarkers, physicians may be able to tell if a patient is not responding to therapy and alter their treatment strategy accordingly," Dr. Roberto Diaz, a radiation oncology resident at the Vanderbilt-Ingram Cancer Center, said in a prepared statement.
"This study provides us with a starting point for understanding how tumors physiologically respond to therapy and a noninvasive technique for monitoring that response," Diaz said.
In another study, scientists at the Translational Genomics Research Institute found that 164 genes are involved in regulating the vulnerability of squamous cell head and neck cancer cells to the drug lapatinib.
The U.S. National Cancer Institute explains tumor markers.