- A patient who has a change in receptor status (e.g., PR negative to positive) may be stratified as triple negative or hormone positive, contrary to the most recent receptor testing, for the purposes of the study based upon the clinical course at the discretion of the Study Chair; for HER2 assessment, a negative result is an immuno-histochemistry staining of 0 or 1+, a fluorescence in situ hybridization (FISH) result of less than 4.0 HER2 gene copies per nucleus, or a FISH ratio of less than 1.8