Prediction of Oncotype Dx recurrence score using clinical parameters

Abstract

Objective/Background: The Oncotype Dx test is a genomic test currently used in clinical practice to predict the risk of disease recurrence in estrogen receptor (ER)-positive, HER2-negative breast cancer patients with axillary lymph node-negative or micrometastatic disease. The test is one of several similar genomically based tests available. Although it has a good predictive value, it is expensive and thus constitutes a significant financial burden for health systems. Thus, several attempts have been made to devise low-cost tools that could predict the recurrence score derived from the genomic evaluation using easily obtainable clinical parameters. Methods: Two previously proposed predictive tools were evaluated in a cohort of 201 patients that had undergone the Oncotype Dx test for their efficacy in predicting the Oncotype Dx Recurrence Score (RS). A simple predictor, named GR-PR, based on two available pathologic parameters, grade and progesterone receptor status was devised and also evaluated. Results: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of all three tools were compared and found to be similar for all cutoff points of Oncotype Dx RS. The accuracy of GR-PR was comparable to the best performing of the two other prediction tools for all four cutoff points. Conclusion: The simple GR-PR predictor proposed in this study seems to be at least as accurate as more complex tools and should be the preferred tool for the prediction of Oncotype Dx RS from clinicopathologic parameters when the Oncotype Dx test is not available.

Predictability of 21-Gene Recurrence Score Assay by Using Pathological and Immunohistochemical Parameters in Breast Cancer

“…Similar findings of grade and PR status to be the strongest predictors of RS were reported by Orucevic et al 27 Studies have proposed to rely on grade and PR status to predict the RR and therefore avoid ordering Oncotype Dx assay in ER-positive, HER2-negative, and node-negative tumors, specifically where the resources are limited. 16 Contrary to this, our study revealed a trend toward association for lymph node involvement, and it was observed that RS for cases with no nodal involvement was much higher compared with those with nodes. This may be because, in our sample, the number of cases with positive nodes was 3 times less than that with negative nodes.…”

“…In our study, the RS for grade 3 cases was more than 2 times that of grade 1, and there was a remarkable decrease in RS as the grade decreased. Thibodeau and Voutsadakis 16 also reported a similar trend with all grade 3 tumors having a high RS compared with grades 1 and 2. The interesting finding in this study was that although negativity of PR status was in inverse correlation to RS, having 1+ staining was associated with higher RS compared with no staining.…”

“…Sparano et al 8 reported the benefit of chemotherapy in younger age group (<50 years) with an RS of 16 to 25, which redefined the risk ranges in TAILORx data. On the other hand, Thibodeau and Voutsadakis 16 could not establish any association of age with Oncotype RS. Age lost its significance in multivariate linear regression analysis, indicating a minor contribution to the RS.…”

“…A research group has found a decrease in the use of chemotherapy from 25% to 10% in early BC cases which were ER positive and HER2 negative after the advent of Oncotype Dx. 16 Despite facilitating the selection of high-risk patients for adjuvant chemotherapy, the biggest limitation in the use of Oncotype Dx is the high cost (4175$) of the assay, 17 specifically for developing countries and even in the developed world with insurance-based health care system, which in most cases will not cover for the price of this assay. Therefore, the use of such an expensive test needs to be justified and a correct subset of patients should be selected for this assay based on identification of the parameters which indicate toward higher risk of recurrence or poor prognosis in ER-positive cases.…”

Clinical Impact of a Novel Model Predictive of Oncotype DX Recurrence Score in Breast Cancer

“…Several predictive models for RS have been reported, and age, tumor size, nuclear grade, lymphovascular invasion, histological type, ER, PgR, HER2, and Ki-67 have been reported as clinicopathological factors associated with RS (2,(6)(7)(8)(9)(10)(11). In the present study, we specifically utilized four immunohistochemical markers that are routinely used to determine the intrinsic breast cancer subtype in clinical practice.…”