Bloom–Richardson grading system
The Bloom–Richardson grading system from 1957 refers to a breast cancer classification system to grade breast cancers, and was the precursor of the present criteria, the modified Bloom–Richardson–Elston grading system (also called the Nottingham system.) 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.
Summary of semiquantitative method for assessing histologic grade in Breast Carcinoma
Tubule formation >75% 1 point 10%-75% 2 point <10% 3 points
Nuclear pleomorphism Small, regular uniform cells 1 point Moderate increase in size and variability 2 points Marked Variation 3 points
Mitotic counts Dependent on microscope field area 1-3 points
- Bloom, HJ; Richardson, WW (1957). "Histological grading and prognosis in breast cancer; A study of 1409 cases of which 359 have been followed for 15 years". British Journal of Cancer 11 (3): 359–77. PMC 2073885. PMID 13499785.
- Elston, CW; Ellis, IO (1991). "Pathologic prognostic factors in breast cancer. I. The value of histological grades in breast cancer. Experience from a large study with long-term follow-up". Histopathology 19 (5): 403–10. doi:10.1111/j.1365-2559.1991.tb00229.x. PMID 1757079. "Republished". 2002. doi:10.1046/j.1365-2559.2002.14892.x.
- Genestie, C.; Zafrani, B.; Asselain, B.; Fourquet, A. et al. (1998). "Comparison of the prognostic value of Scarff-Bloom-Richardson and Nottingham histological grades in a series of 825 cases of breast cancer: Major importance of the mitotic count as a component of both grading systems". Anticancer Research 18 (1B): 571–6. PMID 9568179.
- "National Comprehensive Cancer Network (NCCN) guidelines, Breast Cancer" (Version 2.2011).
- Fletcher, DM. Diagnostic Histopathology of Tumors 2 (4 ed.).