BLOOM HJ, RICHARDSON WW.
"Histological grading and prognosis in breast cancer; a study of 1409 cases of which 359 have been followed for 15 years."
Br J Cancer. 1957 Sep;11(3):359-77.
I➜The Bloom–Richardson grading system originally described in 1957, refers to a classification system to grade breast cancers.
The grading as used in the Nottingham prognostic index is sometimes referred to as the Nottingham modification of the Bloom-Richardson system or Nottingham grade. Other synonyms include Elston grade or Elston-Ellis modification.
The cells and tissue structure of the breast cancer are examined histopathologically to determine how aggressive the cancer is. Lower grade tumors, with a good prognosis, can be treated less aggressively, and have a better survival rate. Higher grade tumors are treated more aggressively, and their intrinsically worse survival rate may warrant the adverse effects of more aggressive medications. The references highlight the historical and current criteria; the latter system is judged more reproducible and is the recommended grading method. The breast cancer classification article has further details of current breast cancer grading criteria. Main source:Wikipedia