Abstract P5-11-07: ER Positive Screen Detected Breast Cancers (SDBC) Do Not Require Chemotherapy

Abstract

Abstract Background: Meta-analysis of symptomatic breast cancer trials advises chemotherapy to women less than 70 years of age at high risk of death (i.e benefit of >1% survival benefit from treatment) but UK screen detected breast cancers (SDBC) in women aged 50 to 65 years have a 97.2% relative survival compared to 77.6% for symptomatic cancers in the ABS at BASO audit. Methods: To determine which women benefit from chemotherapy, we have analysed 1,607 symptomatic and SDBC in one unit. Results: SDBC had a significantly lower risk of relapse with the five year breast cancer mortality for ER positive breast cancers being low in the Excellent, Good and Moderate Prognostic Group 1 but being significantly higher in the Good Prognostic Group and Moderate Prognostic Group 1 diagnosed symptomatically. Symptomatic cancers in the Good Prognostic Group (GPG) and Moderate Prognostic Group 1 (MPG1) had a hazard ratio of 5.34 (1.61-17.75) and 14.46 (10.4-106.0) respectively for cancer death compared to SDBC. NPI Index Score and Mortality in SDBC and Symptomatic Cancers treated in Manchester 1990-98 - ER ER positive cancers detected by screening (but not ER negative) had a 0.6% mortality annually whereas the symptomatic cancers had a 10% annual mortality in the first five years. The UK National ABS/BASO Audit was used to confirm the findings (Table 2). Data over the last ten years of follow-up from the ABS at BASO audit indicates significant survival improvements in the Moderate Prognostic Group 2 (MPG2) and the Poor Prognostic Group (PPG) for SDBC. NHSBSP and ABS at BASO Breast Screening National Audit Data for Invasive SDBCs diagnosed between 1990 and 2002 Discussion: Thus, ER positive SDBCs represent a group which have a low risk of relapse and do not require chemotherapy. The improvements in survival of SDBC relate to better treatment of ER negative and HER2 positive breast cancers and have occurred predominantly in the MPG2 and PPG. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-11-07.