ERBB2 and breast carcinoma: Although a FISH test was more expensive than an IHC test (US$339 versus US$118), they found that the cost-effectiveness ratio of correctly diagnosing and treating HER2-positive breast cancer in a larger percentage of women is greater than the initial upfront cost of utilizing both tests.12 At our institution, the additional cost of adding reflex HER2 FISH testing was negligible compared with the revenue we obtained by appropriately treating the additionally identified HER2-positive patients.