Allred scoring for ER reporting and it's impact in clearly distinguishing ER negative from ER positive breast cancers.

OBJECTIVE To determine the scoring of Estrogen Receptor (ER) status in carcinoma breast by Allred method that is essentially bimodal and to compare the results with a conventional scoring system. MATERIALS AND METHODS A retrospective, comparative study carried out at Aga Khan University Hospital Section of Histopathology over a period of 18 months, i.e., Jan 2005 to June 2006. Anti ER antibody (clone D07) was used for all IHC stains using envision detection system. ER stains of 860 consecutive breast cancer cases were reviewed and rescored by both conventional and Allred method of ER scoring. RESULTS Comparison of results showed that there was a substantial decrease in weak positive cases from 18% to 5% by rescoring using Allred scoring system compared to conventional scoring. The data was analyzed using chi square test. CONCLUSION The sensitivity and specificity of Allred method were calculated; Sensitivity of Allred method was 99.4% & Specificity of Allred method was 99.5% whereas sensitivity and specificity of conventional method was 88.0% and 84% respectively