The impact of the Oncotype Dx breast cancer assay in clinical practice: a systematic review and meta-analysis

Abstract

The impact of the Oncotype Dx (ODX) breast cancer assay on adjuvant chemotherapy (ACT) treatment decisions has been evaluated in many previous studies. However, it can be difficult to interpret the collective findings, which were conducted in diverse settings with limited sample sizes. We conducted a systematic review and meta-analysis to synthesize the results and provide insights about ODX utility. Studies, identified from PubMed, Embase, ASCO, and SABCS, were included if patients had ER+, node –, early-stage breast cancer, reported use of ODX to inform actual ACT decisions. Information was summarized and pooled according to: (1) distribution of ODX recurrence scores (RS), (2) impact of ODX on ACT recommendations, (3) impact of ODX on ACT use, and (4) proportion of patients following the treatment suggested by the ODX RS. A total of 23 studies met inclusion criteria. The distribution of RS categories was 48.8 % low, 39.0 % intermediate, and 12.2 % high (21 studies, 4,156 patients). ODX changed the clinical-pathological ACT recommendation in 33.4 % of patients (8 studies, 1,437 patients). In patients receiving ODX, receipt of ACT were: 28.2 % overall, 5.8 % low, 37.4 % intermediate, and 83.4 % high. High RS patients were significantly more likely to follow the treatment suggested by ODX versus low RS patients RR: 1.07 (1.01–1.14). The pooled results are consistent with most individual studies to date. The increased proportion of intermediate scores relative to original estimates may have implications for the clinical utility and cost impacts of testing. In addition, low versus high RS patients were significantly more likely to follow the ODX results, suggesting a tendency toward less aggressive treatment, despite a high ODX RS. Finally, there was a lack of studies on the impact of ODX on ACT use versus standard approaches, suggesting that additional studies are warranted.

Use of modified Magee equations and histologic criteria to predict the Oncotype DX recurrence score

“…30,[47][48][49] However, the widespread use of this test has come into question recently, as the literature has suggested that certain cases might be risk stratified more costeffectively using histopathologic variables. [50][51][52][53][54] Our data support this. The Magee equations, along with histologic and immunohistochemical criteria, may be a more cost-effective alternative in identifying cases that would likely stratify into a high or low Oncotype DX risk-stratification category.…”

Loss of ALCAM expression is linked to adverse phenotype and poor prognosis in breast cancer: A TMA-based immunohistochemical study on 2,197 breast cancer patients

“…Data have shown that the recurrence score was low in 48% of the first 20,050 tested patients and in this group there is minimal, if any, benefit from adjuvant chemotherapy (32,33). On the other hand, current knowledge indicates that approximately up to 77% of breast cancer patients may be exposed to chemotherapy toxicity and costs with little or no clinical benefit (34). Given the remaining ~30% of 'unnecessary' chemotherapies, these existing tests are still far from ideal.…”

Identification of estrogen-responsive genes based on the DNA binding properties of estrogen receptors using high-throughput sequencing technology

“…Recently, classification of breast cancer subtypes based on HER2 expression as well as ER and PR status was performed to determine the appropriate treatment and to predict the patient's prognosis [23] . In addition, it was shown that the expression patterns of several genes clinically correlate with the outcome of adjuvant therapy and the prognosis of breast cancer patients [24] . Thus, gene expression profiling will provide a new taxonomy of breast cancer.…”