Comparison of IHC testing for HER-2 in breast cancer specimens before and after adoption of new 2013 ASCO/CAP guidelines in a single institution: Impact on outcome and cost.

Abstract

e18294 Background: Revised guidelines for HER-2 testing in Breast Cancer Specimens occurred in 2007 and again in 2013 with an intention to capture more patients who could benefit from HER-2 directed therapy. Methods: The purpose of this study was to compare the HER 2 + cases outright and the equivocal cases that resulted in a reflex FISH test that was ultimately positive utilizing both guidelines. The number of equivocal tests results and those that ultimately were positive, negative or remained equivocal were quantitated. A retrospective analysis on specimens from 2003-2008 and 2013-2016 was performed. Results: see table. Conclusions: An expansion of 8.8% is seen in the equivocal category after adoption of the 2013 guidelines. Despite an increased number of reflex FISH testing there was no significant increase in the number of FISH positive patients. The end result was a greater delay in time to treat patients appropriately for send-out FISH tests and significant increase in costs for testing that did not result in management change. If the additional costs are multiplied by the number of patients with breast cancer each year and resultant equivocal results calculated for the almost 9% increase, that extra cost is close to 12 million dollars. Based on our small institution study, reconsideration of guideline criteria is important in this era of value-based medicine. [Table: see text]