THE MSBR BREAST CANCER GRADING SYSTEM

The "mSBR grade" (modified Scarf-Bloom-Richardson) is arrived at (by pathologists) by evaluating the cancer for the following two parameters in order to "sum" or add-up the designated points in order to produce an Arabic numerical sum score. Score ranges equate to Roman-numeral grades, there being four grades. MSBR stands for "modified Scarff-Bloom-Richardson method".

	TUBULES: (a pattern or architectural parameter assessing cellular organization...the tumor's ability to maintain some semblance of normal order...how bad the tissue organization looks)......not a factor in this system
	NUCLEAR [size/shape] VARIATION: (a cytological/cellular parameter...how bad the cells look [B-R grade here]) 1 point, if only mild nuclear enlargement, no/mild darkening of chromatin [nuclear DNA/chromosomes], no/mild variation of nuclear shapes and sizes. 2 points, if moderate such changes. 3 points, if nuclei quite large, or bizarre, or have prominent nucleoli, and are quite dark [hyperchromatic]
	MITOTIC ACTIVITY: (a growth-rate parameter which is determined in the tumor area showing the fastest growth rate, usually the tumor periphery, counting the number of mitotic figures in ten high-power microscopic fields [hpf]...400x [40x objective and 10x ocular]) 1 point, 0-1 mitotic figures per 40x high-power field. 2 points, 2 " " " " " 3 points, 3 or more " " " "

Now, having assigned the points for the two parameters, one simply adds them up and compares to the following list. For example: a tumor has moderate nuclear abnormalities (2 points), and 2 mitotic figures per hpf (2 points)...a total of 2 pt. plus 2 pt. equals a total 4 points. This assigning of numerical values adds a sort of discipline to the pathologist's estimations.

	2 total points is defined as mSBR Group I
	3 total points is defined as mSBR Group 2
	4 total points is defined as mSBR Group 3
	5 total points is defined as mSBR Group 4
	6 total points is defined as mSBR Group 5

Dr. Le Doussal, champion of this system, found that Groups 1-3 accounted for 33% of the total cases and had a distinctly lower risk for developing metastasis than even Groups 3 & 4. That is, patients with well differentiated tumors and low mitotic counts have an excellent prognosis.