(Ivanhoe Newswire) -- A 21-gene test that predicts whether early stage
breast cancer patients will benefit from chemotherapy is having a big impact on
treatment decisions by patients and doctors alike.
Based on test results, doctors changed their treatment recommendations in 31.5
percent of cases, while 27 percent of patients changed their treatment
decisions. In most cases, both doctors and patients decided to avoid
chemotherapy.
Medical oncologist and assistant professor in the Department of Medicine, Loyola
University Chicago Stritch School of Medicine, Dr. Shelly Lo, led the study. The
multi-gene test, Oncotype DX, examines 21 genes from a tumor sample to determine
how active they are and how likely the cancer is to recur. For women with low
scores, chemotherapy is not recommended.
More than 120,000 breast cancer patients have undergone the test since it became
commercially available in 2004. The test is intended for patients who have
estrogen receptor-positive breast cancer that has not spread to the lymph nodes.
About 100,000 such cases are diagnosed each year.
"The trend in oncology is towards personalized medicine," Lo was quoted as
saying. "We likely will see more tests similar to this one in the future."
The study included 89 breast cancer patients who received the gene test. They
were treated at Loyola, University of Michigan, University of California at
Davis and Edward Hospital in Naperville, IL.
Doctors changed treatment plans for 28 patients. In 20 of these cases, they
changed their treatments from hormone therapy plus chemotherapy to hormone
therapy alone. Twenty-four patients changed their treatment decisions, including
nine who dropped chemotherapy.
"This is the first study to show that results from this test simultaneously
impact decisions by physicians as well as patients," said Lo.
Doctors said the test increased their confidence in their treatment
recommendations in 76 percent of cases. And in 97 percent of cases, doctors said
they would order the test again. After receiving test results, patients reported
they were significantly less conflicted about their decision and felt
significantly less anxiety about their situations.
"This test of patients' own breast cancer provides us with greater certainty of
who derives benefit from chemotherapy and who can safely avoid it," senior
author Dr. Kathy Albain, professor in the Department of Medicine, Division of
Hematology/Oncology, Stritch School of Medicine, was quoted as saying.
The test costs $3,910, and generally is covered by insurance. Researchers said
the test could lower overall costs by avoiding the expense of unnecessary
chemotherapy in some patients.
SOURCE: Journal of Clinical Oncology, January 11, 2010
