Clinical utility of the IHC4+C score in oestrogen receptor-positive early breast cancer: a prospective decision impact study

Abstract

Background:Most oestrogen receptor (ER)-positive early breast cancer diagnosed today is highly curable with multimodality treatment. Systemic adjuvant treatments including endocrine therapy and chemotherapy have made a significant contribution to the increasing cure rates over the past three decades. However not all women will require chemotherapy. The IHC4+C score is a prognostic tool that integrates four immunohistochemical measures with clinicopathological features to estimate the residual risk of distant recurrence at 10 years in post-menopausal women with ER-positive breast cancer who have received 5 years of endocrine therapy. Retrospective studies indicate that the test can identify a set of women that are at such low risk of recurrence that chemotherapy can be of little benefit.Methods:In this study, 124 patients were prospectively selected from the multidisciplinary team meeting between January 2013 and April 2014 for IHC4+C testing. Adjuvant systemic treatment recommendations by clinicians were recorded without and with the availability of the score in addition to the patient's decision.Results:There was concordance in the MDT's recommendation without and with the availability of the score in 73% of cases. Clinicians recommended chemotherapy or at least its discussion to 74 (59%) patients, which fell to 32 (34%) patients after the IHC4+C score was made available, sparing one in four tested patients a chemotherapy recommendation, along with its toxicity and expense.Conclusion:This decision impact study shows that when used by clinicians in the multidisciplinary team meeting for adjuvant decision-making, a significant proportion of patients are spared chemotherapy recommendations.

Ki67 Is an Independent Predictor of Recurrence in the Largest Randomized Trial of 3 Radiation Fractionation Schedules in Localized Prostate Cancer

“…Patients with low mean Ki67 could be reassured that they are likely to have a good prognosis and might be candidates for studies of reduced ADT. This study suggests that Ki67 is of maximal predictive benefit when used as a continuous variable; this method of stratification is used effectively in the clinic for Ki67 and other expression profiling-based algorithms 19 , 22 .…”

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Extended Adjuvant Endocrine Therapy in Hormone Receptor-Positive Early Breast Cancer

“…The most widely used of these, Oncotype DX (by Genomic Health), is highly effective in assessing the early recurrence risk (within 5 years); however, it is less helpful in quantifying later recurrence [25,26]. Similar characteristics (with accurate assessment of the early recurrence risk but poor quantification of the later recurrence risk) have been noted with other molecular assays, including Mammaprint and the IHC4 score (summarising 4 immunohistochemical parameters) [27,28]. The Prediction Analysis of Microarray 50 (PAM50) assay and its resultant risk of recurrence (ROR) score (assessing 50 genes by quantitative polymerase chain reaction (qPCR) with subtyping of the lesions into luminal A, luminal B, human epidermal growth factor receptor 2 (HER2)-enriched and basal-like types) appears to offer more long-term predictive data with superior recurrence risk quantification in the 5-10-year range [29].…”

Gene Expression Profiling and Expanded Immunohistochemistry Tests to Guide Selection of Chemotherapy Regimens in Breast Cancer Management: A Systematic Review

“…Evidence from one prospective study (50) demonstrated that the IHC4 test led to changes in treatment recommendations for 34% of the patients, with 25%…”