Scientists from the Fox Chase Cancer Center said the findings indicate two out of three cancer cells carry at least one mutation that may be targeted, or medicated, by an existing drug or treatment.
 

The study, presented at meeting of the American Society of Clinical Oncology this month, suggests doctors may one day conduct DNA testing on tumors before deciding on a treatment regimen.
 

"Extended [DNA] sequencing of a patient's tumor is not something that's routinely done now," said Patrick Boland, M.D., a hematology/oncology fellow at Fox Chase who helped conduct the study. "Our ultimate hope is that, if we determine testing is worthwhile, it becomes routine for a doctor to send off a tumor sample to look for mutations before deciding on a course of treatment."
 

For the study, Dr. Boland and his colleagues performed genetic tests on 77 patients with solid tumors — primarily inflammatory breast cancer and colon cancer — to track nearly 200 mutations associated with cancer.
 

The results showed 96 percent of the patients carried one genetic mutation or more. Nearly two-thirds had at least one mutation the researchers termed "actionable," meaning it can be treated by a drug that is on the market or in development.
 

Dr. Boland stressed that even though these genetic defects are present, in many cases it's not clear which ones are causing the cancers.
 

"Even if we find a [change], we don't know if it's something that's driving the tumor to grow or something that just happened along the way," he said, noting more research to understand the basic biology of tumors. "We need our colleagues in the basic sciences to continue investigating the genetic underpinnings of cancer, so we can determine which mutations are most important to target."