FDA Approves New Genetic Test for Breast Cancer

Jan 20, 2008
First-of-its-kind product gives prognostic information and
may help health care providers in deciding best follow-up

The U.S. Food and Drug Administration has approved a test
that helps in assessing the risk of tumor recurrence and
long-term survival for patients with relatively high-risk
breast cancer. The TOP2A FISH pharmDx is the first approved
device to test for the TOP2A (topoisomerase 2 alpha) gene
in cancer patients.

The TOP2A gene plays a role in DNA replication. The TOP2A
FISH pharmDx test uses fluorescently labeled DNA probes to
detect or confirm gene or chromosome abnormalities, a
technology known as fluorescent in situ hybridization

The recurrence of cancer depends partly on certain genes
whose activity may be altered by changes in the number of
gene copies in the tumor. Changes in the TOP2A gene in
breast cancer cells mean there is an increased likelihood
that the tumor will recur or that long-term survival will
be decreased.

"When used with other clinical information and laboratory
tests, this test can provide health care professionals with
additional insight on the likely clinical course for breast
cancer patients," said Daniel Schultz, M.D., director of
FDA's Center for Devices and Radiological Health. "It can
also provide valuable information to assist health care
providers and patients in better understanding the biology
of breast cancer disease."

The test is suitable for breast cancer patients who are
premenopausal or for whom tumor characteristics, such as
tumor size or lymph node involvement, suggest a higher
likelihood of tumor recurrence or decreased survival.

The FDA reviewed evidence that the test has been properly
validated for its intended use.

The product was studied in Danish patients who were treated
with chemotherapy after removal of a breast tumor. The test
is conducted on a small piece of the removed tumor. The
removed piece is stained with the FISH chemicals and
studied under a microscope.

The company submitted data from a study using tumor samples
and clinical data from 767 patients with high risk tumors
at 21 centers in Denmark. These studies confirmed that the
test was useful in estimating time to local or distant
recurrence and overall survival in women who received
certain chemotherapy regimens assisting in the treatment of
the disease.

The product is manufactured by Dako Denmark A/S (Glostrup,

Source: FDA