This is a very interesting question. My practice is not to utilize anti-estrogen in true ER Negative /PR positive cases ( after repeating the assay on another tissue sample to rule out a false negative ER assay). EBCTCG meta analysis of randomized trials published in Lancet in 2011 showed only sli...

Based upon the ASCO/CAP guidelines from 2010, I would treat patients in the operable setting with anti-estrogen therapy if ER and/or PR > 1%. As described in guidelines (Hammond et al JCO 2010), the studies can vary in terms of the predictive role of PR, independent of ER values. In some retrospe...