[237] Does Clinicopathologic Features Influence the Use of Adjuvant Chemotherapy in Early-Stage Breast Cancer Patients Who Have an Oncotype DX Intermediate Risk Score?

Michaela T Nguyen, Zhengming Chen, Timothy D'Alfonso, Alexander Stessin, Himanshu Nagar, Mary Hayes, Sandra J Shin. Weill Cornell Medical Center, New York, NY; New York Presbyterian, Weill Cornell Medical Center, New York, NY

Background: Oncotype DX (Genomic Health) is a commercially available 21 gene RT-PCR assay that is widely used to determine the risk of distant recurrence and the benefit of adjuvant chemotherapy in patients with early stage breast cancer. This assay calculates a recurrence score (RS) that is stratified as low, intermediate or high. Patients with low RS have been shown to gain little to no benefit from adjuvant chemotherapy while those with a high RS derive large benefits from adjuvant therapy. Currently, it is unclear whether patients with an intermediate RS (18-30) benefit from adjuvant chemotherapy. The objective of this study was to determine if routinely available clinicopathologic parameters impact the decision for adjuvant chemotherapy utilization in breast cancer patients found to have an intermediate RS.
Design: A single-center retrospective study (2005-2012) was conducted on 543 patients with invasive breast carcinoma who had Oncotype DX testing performed as part of their routine clinical care. Age, tumor size, tumor grade, lymphovascular invasion, nodal status, ER/PR status, Her2neu status, Ki-67 index, Oncotype DX RS, and treatment were obtained by electronic medical record for each patient. Logistic regression was performed to determine the association between clinicopathologic parameters (age, tumor size, tumor grade, presence of lymphovascular invasion, lymph node micrometastasis, and Ki-67 index) and the utilization of adjuvant chemotherapy.
Results: 154 of 543 (28.3%) early-stage breast cancer patients (ER/PR positive, Her2neu negative, node negative) was found to have an intermediate RS by Oncotype DX testing. 56 of 154 (36.4%) received adjuvant chemotherapy while 98 of 154 (63.4%) did not. Twelve patients refused adjuvant chemotherapy (recommended) and thus, excluded from the analysis. A statistically significant association between high tumor grade and the utilization of adjuvant chemotherapy was identified (OR 10.2, 95% CI 2.97, 35.1; p-value <0.0001). Associations of remaining clinicopathologic parameters with the utilization of adjuvant chemotherapy were not significant.
Conclusions: Our results suggest that high tumor grade is a clinicopathologic feature that significantly favored the use of adjuvant chemotherapy in early stage breast cancer patients classified in the intermediate risk group by Oncotype DX testing.
Category: Breast

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 29, Wednesday Morning

 

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