AbstractThe determination of steroid receptors in human breast cancers has assumed increasing importance over the past several decades. Improper handling of the specimens could affect results obtained. This study details the effects excessive levels of heat that occur with the use of electrocautery can have on steroid receptor quantities and localization. Twelve resected primary and metastatic human breast cancers were analyzed for cytoplasmic and nuclear receptors by biochemical analysis. In addition, steroid binding was determined by direct fluorescent histochemical techniques. To a portion of each resected specimen a Boviecwas applied to simulate electrocautery resection. Analysis of the different portions of the same tumor revealed that there was a decrease in measurable cytoplasmic receptor in all cauterized specimens and a concomitant increase in the nuclear receptor. A similar shift in steroid binding was noted in all the specimens analyzed by fluorescent histochemical techniques. The results of this study show that the application of excessive heat to human breast cancers will lead to false negative biochemical steroid receptor determination by shifting the receptors intranuclear.