Oncotype DX Assay Changes 29% of Treatment Decisions in Patients with Stage II Colon Cancer

VBCC - March 2012, Volume 3, No 2 - Gasterol Intestinal Symposium

San Francisco, CA—Results obtained on the Oncotype DX Colon Cancer Assay led to changes in treatment decisions 29% of the time for patients with stage II colon cancer, according to a survey of community oncologists reported at the 2012 Gastrointestinal Cancers Symposium. "One of the more difficult decisions is what stage II patients to treat," said lead investigator Thomas H. Cartwright, MD, Ocala Oncology, FL. "In stage II patients, we typically rely on more subjective factors, number of lymph nodes, tumor grade, and so forth. This test helps us determine recurrence risk." The difference between this assay and the Oncotype DX assay for breast cancer (see page 16) is that the breast cancer test is not only prognostic but also predictive, whereas the test in colorectal cancer (CRC) is prognostic only. Some physicians, therefore, have wondered about the utility of the test in CRC. That treatment for more than 25% of patients was clearly determined by test results confirms the assay's utility in the management of CRC, Dr Cartwright maintained.

Oncotype DX, which produces a 12-gene recurrence score, has been commercially available since January 2010. This study was the first evaluation of its impact on treatment recommendations in CRC in a survey of medical oncologists. Similar surveys in breast cancer have shown that treatment decisions are altered approximately 30% of the time based on test results. The web-based survey involved 116 US oncologists who had ordered Oncotype DX testing for ≥3 patients with stage II CRC. Most came from a community practice setting and had an average of 16 years of oncology practice. Half of the oncologists saw >40 patients with newly diagnosed CRC in a typical year. The 34-item survey recorded patient characteristics, preassay and postassay treatment recommendations, and the oncologist's general practice patterns.

Impact of Test on Treatment Recommendations
Of the 116 respondents, 92 (79%) had a treatment recommendation before ordering the assay. Of these recommendations, 57% included chemotherapy. After the 12-gene recurrence score was obtained, 29% of the recommendations changed. For 67%, the treatment intensity decreased; for 33%, the treatment intensity increased, said Dr Cartwright. Decreased treatment intensity was defined as a change from chemotherapy to observation or a change from oxaliplatin-containing to non–oxaliplatin-containing chemotherapy. Increased intensity was defined as a change from observation to any chemotherapy or from non–oxaliplatin-containing to oxaliplatin-containing chemotherapy. "These results suggest that the use of the recurrence score may be associated with a meaningful change in treatment recommendations for stage II CRC patients," Dr Cartwright concluded, "and may lead physicians to reduce the treatment intensity, which contributes to the assay's cost-effectiveness."— CH

Related Items
For Pancreatic Cancer, Neoadjuvant Chemoradiation Cost-Effective Compared with Surgery First
Caroline Helwick
VBCC - March 2012, Volume 3, No 2 published on April 20, 2012 in Gasterol Intestinal Symposium
Everolimus Has Minimal Economic Impact on Treatment of Pancreatic NETs
Caroline Helwick
VBCC - March 2012, Volume 3, No 2 published on April 18, 2012 in Gasterol Intestinal Symposium
Last modified: May 28, 2014
  • Rheumatology Practice Management
  • American Health & Drug Benefits
  • Value-Based Cancer Care
  • Value-Based Care in Myeloma
  • Value-Based Care in Neurology