Additional Studies Performed on Breast Tumors

So there are ancillary studies, which we perform on all breast cancers. The very minimum ancillary studies, which should be performed, are for estrogen and progesterone receptor and also for the overamplification or overexpression of HER-2/neu.

Estrogen and progesterone receptors are found on normal breast tissue cells. They are also often found on breast tumor cells, and when they are found on breast tumor cells, the hormones estrogen and progesterone are actually known to stimulate those cells. And this is very interesting information for the oncologist because, not only do we know that tumors which tend to express estrogen and progesterone receptors are typically more well-differentiated and behave better, but we also have targeted therapies for patients whose tumors express estrogen and progesterone. So it’s very important for the pathologist to not only perform these studies, but perform them to a high standard and interpret them correctly.

Another ancillary study, which pathologists perform on all tumors, and it’s very important to look for in your pathology report, is HER-2/neu. HER-2/neu is a gene, which is overexpressed by some breast cancers. When it is overexpressed, it tends to be associated with more aggressive tumors, but it is a very important thing to know that you have an overexpressing or a HER-2/neu overexpressing breast cancer because we have a targeted therapy called Herceptin, which if an oncologist sees that you have an HER-2/neu overexpressing tumor, can often use this extra tool, or this drug, to help treat your breast cancer.