Bloom-Richardson grade

Overview
The Bloom-Richardson grade (BR grade) is a a histologic grade assigned by pathologists to breast cancers. It is the most common type of cancer grade system currently used. It is a semi-quantitative grading method based on three morphologic features of invasive breast cancers. The morphologic features that are used are:


 * 1) degree of tumor tubule formation (percentage of cancer composed of tubular structures)
 * 2) tumor mitotic activity (rate of cell division)
 * 3) nuclear pleomorphism of tumor cells (nuclear grade, change in cell size and uniformity)

Each of these features is assigned a score ranging from 1 to 3. The scores are then added together for a final sum that will range between 3 to 9. This value is then used to grade the tumor as follows :


 * 3-5 Grade 1 tumor (well-differentiated).
 * 6-7 Grade 2 tumor (moderately-differentiated).
 * 8-9 Grade 3 tumor (poorly-differentiated).