Hormone Receptor Negative Breast Cancer - Food For Thought

There was recently an on-line conference about hormone receptor negative breast cancer sponsored by www.breastcancer.org. The moderator of the conference was an oncologist named Dr. Jennifer Armstrong, M.D. Although not much new information was offered, it was refreshing to see someone finally focus on this topic. One of the things that wasn't said is something that an oncologist once told me, i.e. that if you sample tissue from a breast cancer tumor in different places, it's possible to get different results. For example, the results of one sample might be estrogen negative, 30% positive progesterone while the results of a second sample from the same tumor could be estrogen 30% positive and progesterone 70% positive. In this on-line conference, one of the doctors stated that these hormone receptor tests are difficult to perform, and therefore it may make sense to have the test repeated. If two different results are obtained, how then do doctors/patients confidently make decisions about which drugs to use as treatments?