After endocrine therapy in women with hormone receptor positive (HR+) breast cancer, PAM50 risk of recurrence (ROR) score and intrinsic subtype may be able to identify node-positive patients with limited risk of metastasis, according to a recent study published in Annals of Oncology.
Michael Gnant, MD, of the Medical University of Vienna and fellow researchers looked at tissue specimens of 543 node positive patients who received adjuvant tamoxifen and/or anastrozole.
“As most node-positive patients with HR+ breast cancer currently receive adjuvant chemotherapy improved methods for characterization of individuals’ metastasis risk are needed to reduce overtreatment,” they noted.
Primary objective was to evaluate prognostic information of ROR score with combined clinical standard variables in patients with one positive node (1N+) or two/three positive nodes (2-3N+).
The authors found that, upon multivariate analysis, PAM50-derived ROR score provided reliable prognostic information beyond established clinical factors for patients with both 1N+ and 2-3N+.
The 10-year distant recurrence risk was significantly increased in the high-risk group based on ROR score for 1N+, compared to the low-risk group, as well as the combined low/intermediate risk group for patients with 2-3N+.
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In addition, luminal A intrinsic subtype demonstrated a significantly lower risk of distant recurrence in patients with 1N+ and 2-3N+ compared to luminal B subtype.
“The PAM50 test is a valuable tool in determining treatment for node-positive early breast cancer patients,” the authors concluded.
- Gnant, M., et al. “Identifying Clinically Relevant Prognostic Subgroups of Postmenopausal Women with Node-positive Hormone Receptor Positive Early Stage Breast Cancer Treated with Endocrine Therapy: A combined analysis of ABCSG-8 and ATAC using the PAM50 risk of recurrence score and Intrinsic Subtype.” Annals of Oncology. doi: 10.1093/annonc/mdv215. [epub ahead of print]. May 1, 2015.