Results from three studies of the Oncotype DX? Colon Cancer test (Genomic Health) presented the 2013 ASCO Gastrointestinal Cancers Symposium, show that diagnostic test significantly contribute to changes in treatment decisions.
The various studies confirm that the Recurrence Score? (RS) results changed treatment recommendations in 45% of the enrolled stage II colon cancer patients. A seperate health economics study suggest the use of the test may result in a significant reduction in direct medical costs and improve patient well-being.
CALGB 9581 trial
A large clinical validation study of stage II colon cancer patients enrolled in CALGB 9581 trial further confirming that theOncotype DX test improves the ability to differentiate higher from lower recurrence risk beyond conventional factors. Based on evaluated specimens from 690 stage II colon cancer patients enrolled in CALGB 9581, a phase III randomized US cooperative group trial, the study confirmed the prediction of recurrence in stage II colon cancer.
The CALGB 9581 study population, which had, on average, low/standard recurrence risk, traditional clinical and pathologic variables were demonstrated to be poor discriminators of recurrence risk, with only MMR being significant in univariate analyses (p=0.04). By contrast, the Recurrence Score? result was the factor most significantly associated with recurrence-free interval, in both univariate (p=0.01) and multivariate analyses (p=0.004), demonstrating that the recurrencesScore result predicts recurrence risk with value beyond traditional measures. The remarkable consistency of these results with those from QUASAR reinforces the concept that a high recurrence score result can reveal an underlying biology indicative of more aggressive stage II disease for which adjuvant therapy may be more appropriate, particularly for the standard risk patients with T3, N0, MMR-P tumors, a population in which traditional markers are not informative 
“These new data reinforce the value of an individualized recurrence risk assessment score that enables physicians to identify those at high risk of recurrence who can experience a greater potential benefit from chemotherapy, as well as patients with a low risk of recurrence who can be spared unnecessary treatment,” said Steven Shak, M.D., chief medical officer and executive vice president for research and development at Genomic Health. “Oncotype DX represents an important advance in bringing personalized medicine into the modern paradigm for cancer care. With a growing body of evidence we now have expanded support for broader reimbursement and increased patient access to our colon cancer test.”
Changing 45% of treatment decisions
“Current clinical practice reveals a high level of variability and subjectivity in the treatment of stage II colon cancer patients,” said Steven Alberts, M.D., medical director for the Clinical Research Office in the Mayo Clinic Cancer Center, Rochester, Minn. “The Oncotype DX Colon Cancer test changes the paradigm for predicting individual recurrence risk for stage II colon cancer patients by providing quantitative information which has not been available with conventional measures.”
Conducted in collaboration with the Mayo Clinic Cancer Research Consortium, a prospectively designed study analyzed treatment decisions for 141 stage II, T3 MMR-proficient colon cancer patients across 17 sites demonstrating that the use of the Oncotype DX Colon Cancer test changed treatment decisions 45% of the time and led to an overall reduction in chemotherapy use.
For patients whose treatment recommendations changed, treatment intensity decreased for more than 33 percent of patients (from chemotherapy to observation or from oxaliplatin-containing to non-oxaliplatin containing regimens) and increased for more than 11% of patients (from observation to any chemotherapy or from non-oxaliplatin containing to oxaliplatin-containing treatment).
Reconfirms cost effectiveness
An analysis of 141 patients from 17 sites in the Mayo Clinic Cancer Research Consortium demonstrated the value of using the Oncotype DX test to identify stage II colon cancer patients with low risk of recurrence. After receiving the Recurrence Score results, physician recommendations for adjuvant chemotherapy in patients with low risk of recurrence decreased by 22%, which resulted in direct medical care costs savings of $4,200 per patient. This is the first health economic study of the Oncotype DX Colon Cancer test conducted in clinical practice. A separate modeling study showing that the use of the Oncotype DX test in stage II colon cancer patients may lead to health care cost savings while improving clinical outcomes was recently published in the December 2012 issue of Value of Health.
 Venook AP, Niedzwiecki D, Lopatin M, Lee M, Friedman PN, Frankel W, Clark-Langone K, et al. Validation of a 12-gene colon cancer recurrence score (RS) in patients (pts) with stage II colon cancer (CC) from CALGB 9581. J Clin Oncol 29: 2011(suppl; abstr 3518)
 Abstract #453: “Prospective evaluation of a 12-gene assay on treatment recommendations in stage II colon cancer patients” will be presented on Saturday, January 26, from 7:00?7:55 a.m. Pacific Time at Moscone West, San Francisco, Ca.
 Abstract #391: “Real-world comparative economics of a 12-gene assay for prognosis in stage II colon cancer” will be presented on Saturday, January 26, from 7:00?7:55 a.m. Pacific Time at Moscone West, San Francisco, Ca.
NCT00897429– Studying Tissue Samples From Patients With Stage II Colon Cancer Treated on Clinical Trial CLB-9581
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