[153] The University of Kentucky Model for Selecting Breast Cancer Patients for Oncotype DX Testing

Steven Frame, Meredith Burge, Nicole Miller, Yolanda Brill, Rahul Matnani, Patrick McGrath, Marie-Louise Fjallskog, Luis M Samayoa. University of Kentucky, Lexington, KY; VAMC, Lexington, KY; Uppsala University, Uppsala, Sweden

Background: Currently, the decision on treatment of Estrogen Receptor (ER) (+), Her2-neu (-), N0-1a patients is largely supported by molecular tests such as Oncotype DX. While the benefits of this test are indisputable, the guidelines for ordering it are non-specific and may lead to over-utilization at a significant cost. This study presents a model for Oncotype DX testing, based on common morphologic (H&E) and Immunohistochemical (IHC) variables already established in our daily practices.
Design: Recurrence Scores (RS) from 72 randomly selected N0 patients were compared to levels (%) of ER, Progesterone Receptors (PR), Ki – 67, Cyclin A, Mitotic Index (MI) and Tumor Grade (TG) using univariate regression analyses. Although no one variable showed a significant R value, the ones that correlated the most were selected and given a numerical score according to cut-off levels either previously described (MI and TG) or encountered while performing the analyses (ER and PR) (see table 1). Subsequently, all patients were scored accordingly and paired with their corresponding RS.

Univeristy of Kentucky Model for Oncotype DX testing
 12345
ER expression %>90<90   
PR expression %90 - 10070 - 9030 - 701 - 300
Mitotic Index*IIIIII  
Tumor Grade*123  
Based on the modified combined Bloom Richardson Score


Results: See Figures 1A-D


Conclusions: Although limited by the number of patients and depending on individual practices, results from this study suggest that only patients with scores of 8 and 9 will benefit from Oncotype DX. Patients with scores of 4-7 and > 10 will probably not benefit from the test since their RS are predictable to be low (< 21) and high (>25) respectively. In addition, RS of < 10 were not found in patients with tumors showing <90% ER (+), MI > I and in grade III tumors. These observations indicate that the model may be useful even after the results from the TAILOR X trial become available.
Category: Breast

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 14, Tuesday Afternoon

 

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