Influence of genomics on adjuvant treatments for pre-invasive and invasive breast cancer

Introduction and aimTribute to the improved quality of tumor marker studies all major national and international practice guidelines now recognized the potential clinical value of multivariate genomic prognostic tests. There are several diagnostic companies that offer these products for clinical use. This paper reviews recent trends in genomic prognostic testing in the clinic and briefly discusses future trends.Methods and resultsPublished manuscripts on breast cancer biomarkers, genomic prognostic and predictive tests were reviewed along with abstracts and proceedings of major conferences to extract information on the clinical utility, cost-effectiveness and usage of molecular tests in the management of early stage breast cancers. Genomic test use has steadily increased over the past 5 years, approximately 30%, 13% and 1% of stage I, II and III ER-positive breast cancer breast cancers are tested. Among those who are tested, approximately, 25–30% of the time treatment recommendations change due to test results. Testing is associated with decreased use of chemotherapy overall, however in clinically low risk patients who are tested tend to receive chemotherapy more frequently than low risk patients who are untested. Almost all cost-effectiveness studies concluded that genomic testing is cost effective under a broad range of assumptions when used within current guidelines. Simple immunohistochemistry based assays when performed following a standard operating procedure and combined into a multivariate prognostic model, have the potential to substitute for genomic tests in the future.Discussion and conclusionsGenomic testing, when available, is widely used to assist in adjuvant chemotherapy treatment recommendations for clinically intermediate risk (e.g. grade 2, stage I–II) ER-positive breast cancers.