Evaluation oncotype DX^® 21‐gene recurrence score and clinicopathological parameters: a single institutional experience

Abstract

Aims: Oncotype DX recurrence score (RS) is a clinically validated assay, which predicts the likelihood of disease recurrence in oestrogen receptor-positive/ HER2-negative (ER+/HER2À) breast cancer (BC). In this study we aimed to compare the performance of Oncotype DX against the conventional clinicopathological parameters using a large BC cohort diagnosed in a single institution. Methods and results: A cohort (n = 430) of ER+/ HER2À BC patients who were diagnosed at the Nottingham University Hospitals NHS Trust and had Oncotype DX testing was included. Correlation with the clinicopathological and other biomarkers, including the proliferation index, was analysed. The median Oncotype DX RS was 17.5 (range = 0-69). There was a significant association between high RS and grade 3 tumours. No grade 1 BC or grade 2 tumours with mitosis score 1 showed high RS. Low RS was significantly associated with special tumour types where none of the patients with classical lobular or tubular carcinomas had a high RS. There was an inverse association between RS and levels of ER and progesterone receptor (PR) expression and a positive linear correlation with Ki67 labelling index. Notably, six patients who developed recurrence had an intermediate RS; however, four of these six cases (67%) were identified as high-risk disease when the conventional clinical and molecular parameters were considered. Conclusion: Oncotype DX RS is correlated strongly with the conventional clinicopathological parameters in BC. Some tumour features such as tumour grade, type, PR status and Ki67 index can be used as surrogate markers in certain scenarios.

Expression, assessment and significance of Ki67 expression in breast cancer: an update

“…In our recent study, we found a strong positive correlation between Oncotype DX RS and Ki67 and none of the patients with less than 10% Ki67 expression had high risk Oncotype DX RS while in high Ki67 expression tumours, Oncotype DX RS varies. For example, 54% of tumours with Ki67 >70% has high risk RS compared to 17% that showed low risk RS, supporting the reliability of Ki67 in predicting tumour prognosis and Oncotype DX 83 . In addition, a previous study showed that high Ki67 tumours are at higher risk of relapsing among patients with low risk Oncotype DX, and Ki67 status may help to identify a subset of low risk Oncotype DX patients who could benefit from adjuvant chemotherapy 86 .…”

“…The St Gallen guidelines recommended Ki67 in order to distinguish the molecular subtypes luminal A and luminal B BC 11. Due to its prognostic significance in hormone receptor-positive BC, MKi67 gene is one of the 16 genes that are measured in the Oncotype DX recurrence score (RS) 76–78. There is a high concordance rate between Oncotype DX RS and Ki67 index 36 79 80.…”

Characteristics and prognostic significance of polo‐like kinase‐1 (PLK1) expression in breast cancer

“…BC is the leading cause of cancer‐related deaths in women worldwide and the therapeutic decision of BC patients currently depends on histopathological data and molecular biomarkers 26,39–41 . However, many patients show resistance to treatment due to the clinical heterogeneity of BC 42 .…”

“…BC is the leading cause of cancer-related deaths in women worldwide and the therapeutic decision of BC patients currently depends on histopathological data and molecular biomarkers. 26,[39][40][41] However, many patients show resistance to treatment due to the clinical heterogeneity of BC. 42 For these reasons, research into the molecular biology of treatment response is often aimed at identifying genes with prognostic and predictive impact, especially for TNBC patients, who do not benefit from targeted therapy and show a high rate of recurrence.…”

The added value of ultrasound imaging biomarkers to clinicopathological factors for the prediction of high-risk Oncotype DX recurrence scores in patients with breast cancer

“…Several attempts have been made to determine the correlation between RS and various predictive clinicopathological indicators, including the expression of estrogen receptor (ER) and progesterone receptor (PR), high histologic grade, and Ki-67 proliferation index, which have yielded a variety of models ( 8 - 12 ). However, the predictive performance has varied widely across studies, with the accuracy ranging from 52.5–86.8%.…”