Oncotype DX™ Predicts Local and Regional Recurrences in Breast Cancer Patients

Oncotype DX™ Predicts Local and Regional Recurrences in Breast Cancer Patients

Researchers affiliated with the National Surgical Adjuvant Breast and Bowel Project (NSABP) reported that Oncotype DX Recurrence Score™ predicts the risk of local and regional recurrences in node-negative, hormone receptor-positive, tamoxifen-treated women with breast cancer. These findings expand the predictive value of Oncotype DX, which was previously shown to predict risk of distant recurrences. These results were recently presented at the 28th Annual San Antonio Breast Cancer Symposium (SABCS).

Adjuvant chemotherapy and/or hormone therapy have resulted in better survival among women with early-stage breast cancer. Because some women are at higher risk of cancer recurrence, and are more likely to benefit from these treatments than others, tests to predict risk of recurrence may allow for more individualized treatment approaches.

Oncotype DX is a test indicated for patients with newly diagnosed stage I or II, node-negative, estrogen-receptor positive breast cancer who will be treated with tamoxifen. The test evaluates a panel of 21 genes to predict a patient’s 10-year risk of cancer recurrence. The test classifies patients as being at high, intermediate, or low risk of recurrence based on a Recurrence Score. The

Oncotype DX Recurrence Score has been shown to predict the likelihood of distant recurrence as well as the benefit of chemotherapy.

To determine whether the Oncotype DX Recurrence Score predicts risk of local and regional recurrence, researchers from the NSABP Breast Committee evaluated results from the NSABP B-14 and B-20 clinical trials. These trials included 895 tamoxifen-treated patients, 355 placebo-treated patients, and 424 chemotherapy plus tamoxifen-treated patients.

  • The Oncotype DX Recurrence Score was a significant predictor of local or regional recurrence among the 895 tamoxifen-treated, lymph-node negative, estrogen receptor-positive patients. The Recurrence Score was an important predictor of recurrence regardless of patient age, tumor size, or tumor grade.
  • The Recurrence Score also significantly predicted risk of local or regional recurrence in placebo-treated patients and chemotherapy plus tamoxifen-treated patients.
  • For patients treated with tamoxifen, rate of local or regional recurrence by 10 years after treatment was 4.3%, 7.2%, and 15.8%, respectively for those with low, intermediate, or high Recurrence Scores.
  • For placebo-treated patients, rate of local or regional recurrence was similar between those with intermediate and high Recurrence Scores (approximately 20%) and approximately 11% for those with a low Recurrence Score.
  • For patients treated with both chemotherapy and tamoxifen, all local or regional recurrence rates tended to be low: 1.6%, 2.7%, and 7.8% for patients with low, intermediate, or high recurrence scores, respectively.

The researchers concluded that the Oncotype DX Recurrence Score helps predict the risk of local or regional recurrence in women with node-negative, estrogen receptor-positive breast cancer. Results from Oncotype DX may help to further guide the most appropriate treatment choices for each patient with this disease.

Reference: Mamounas E, Tang G, Bryant J, et al. Association between the 21-gene recurrence score assay (RS) and risk of locoregional failure in node-negative, ER-positive breast cancer: results from NSABP B-14 and NSABP B-20. Proceedings from the 28th annual San Antonio Breast Cancer Symposium. December 8-11, 2005. Abstract # 29.

Related News:Oncotype DX Changes Treatment Decisions in One Quarter of Breast Cancer Patients (12/15/05)

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