Data being presented at the American Society of Clinical Oncology annual meeting in Chicago confirms that Genomic Health’s Oncotype DX assay is capable of identifying breast cancer patients who would benefit from extended hormonal treatment past five years, the company said Thursday.

The study analyzed 1,733 patients from the original NSABP B-14 and B-28 trials. Median follow-up of 13.9 years for the B-14 trial and 11.2 years for B-28 determined that the Oncotype DX Recurrence Score results were linked to distant return after five years in patients whose tumors had high quantitative estrogen receptor expression, the Redwood City, Calif. company said.

The results suggest that extending tamoxifen past five years in patients with high and intermediate Recurrence Scores with higher quantitative ER expression may be very beneficial, the company added. 

“Recent studies have shown that extending tamoxifen treatment for 10 years is associated with better outcomes; however, we still need better tools to identify who those patients are,” Genomic Health spokeswoman Victoria Steiner told Device Daily Bulletin. “We believe these data show that not all ER+ early-stage breast cancers are the same and confirm that the Oncotype DX breast cancer test predicts the likelihood of late recurrence five to 15 years out.”

According to Steiner, Oncotype DX is the only test validated to predict who benefits from chemotherapy and the only test included in all major breast cancer guidelines for treatment decisionmaking.

Oncotype DX was made commercially available 10 years ago and is available worldwide. The company said it is planning further studies in breast, prostate and renal cancers to demonstrate the unique impact of the Oncotype DX test worldwide. — Kellen Owings

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