A first-of-its-kind diagnostic test opens the door to personalized medicine in colon
cancer
Genomic Health’s new
Oncotype DX® Colon Cancer Assay is now available for patients
diagnosed with stage II disease. This test looks at the activity of 12 genes within
a patient’s tumor to assess the likelihood that the patient will experience a recurrence
of their disease within three years of diagnosis. This information, in turn, can
aid patients and their physicians in determining whether or not aggressive treatment
such as chemotherapy is appropriate following the surgery to remove the tumor.
Oncotype DX is the first test of its kind for colon cancer patients, and
while Genomic Health is excited to add a second diagnostic test to its portfolio,
we believe the availability of this new test signals something much more important:
the beginning of a new era in the treatment and management of colon cancer, as personalized
medicine becomes a reality in this disease state.
Advancing the Dialogue Beyond Screening and Treatment
For years, Katie Couric and other public figures have emphasized the importance
of colon cancer screening, urging Americans to get screened since this is one of
the few cancers that can be prevented. These communication efforts have broken the
silence on both colonoscopies and colon cancer, helping erase the stigma around
the screening process and the disease itself.
On the other end of the spectrum, there has been a significant increase in the number
of treatment options for colon cancer patients over the last decade, as several
ground-breaking therapies and new treatment combinations have been developed, following
a lag of nearly 20 years.
Despite these advances in the areas of screening and treatment, helping patients
get a more personalized and precise diagnosis has been largely ineffective until
recently. This is no small issue, particularly for the 30,000 – 40,000 Americans
who are diagnosed with stage II colon cancer each year. For this patient population,
it is not clear which patients should receive chemotherapy after their tumor has
been surgically removed, and which patients will fare well without undergoing that
systemic treatment.
This is a significant dilemma because approximately 20 percent of these patients
will eventually experience a recurrence of their disease, despite what appears to
be an initial cure with surgery alone. While some patients receive chemotherapy
following surgery, determining which patients should most appropriately be treated
has been a major challenge. As a result, some of the patients who could potentially
benefit from chemotherapy are slipping through the cracks while others may be over-treated
and exposed to unnecessary toxicity.
Pioneering a New Paradigm
With such a clear need for better tools to help physicians identify which colon
cancer patients are at the highest risk of experiencing a disease recurrence – and
therefore may benefit from more aggressive treatment – Genomic Health decided years
ago to build on its breast cancer research, and use that expertise to develop a
new diagnostic test for early stage colon cancer patients.
A decade of research on the genomics of cancer has taught us that the information
contained within the biology of the tumor is vital to understanding how that cancer
is likely to behave and progress. While it is important to use novel genomic testing
in concert with traditional clinical observations such as tumor pathologic features
and the patient’s lymph node status, relying on clinical observations alone does
not reveal the entire story.
Through our years of colon cancer studies we have identified 12 genes whose combined
behavior can accurately and reliably predict an individual patient’s risk of recurrence.
And in addition to this important discovery of the 12 genes, our research has also
confirmed what we understand to be a key role of two other markers: T-stage and
Mismatch Repair (MMR).
We’ve learned that a higher T-stage, specifically T4 stage, in colon cancer is predictive
of aggressive disease and therefore is associated with a higher likelihood of recurring.
Conversely, a stage II colon tumor that is identified by laboratory testing as Mismatch
Repair deficient is a good prognostic sign, since those tumors tend to be less aggressive
and less likely to recur.
With the introduction of the Oncotype DX Colon Cancer Assay – and with
our enhanced understanding of the role of T-stage and MMR – it is now possible to
more accurately classify and differentiate these colon cancer tumors, because of
this fundamental new diagnostic paradigm. For the first time, stage II colon cancer
patients and their physicians have a genomic tool that enables them to better understand
the complex inner workings of their individual tumors, opening the door to personalized
medicine for patients with colon cancer.
About Genomic Health
Genomic Health, a life science company founded in August of 2000 and located in
Redwood City, California, is committed to improving the quality of cancer treatment
decisions through the research, development and commercialization of genomic-based
clinical laboratory services. To that end, the company conducts sophisticated genomic
research to develop clinically-validated molecular diagnostics which provide individualized
information on response to certain types of therapy, as well as the likelihood of
disease recurrence. These diagnostic technologies generate information that healthcare
providers and patients can use in making treatment decisions.
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