[1118] Is HER2/neu a predictor for invasive recurrence in DCIS. Nofech-Mozes S, Spayne J, Kahn HJ, Rakovitch E, Arun S, Pignol J-P, Lickley L, Paszat L, Hanna W. Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Toronto Sunnybrook Regional Cancer Centre, Toronto, ON, Canada The risk of transformation into invasive breast carcinoma after DCIS cannot be determined based the Van Nuys Pathologic Classification and Prognostic Index alone. We examined the expression of 9 biological markers with a potential role in tumor progression and their value as prognostic factors with an emphasis on predicting invasive recurrence in 133 patients with pure DCIS. All patients were treated with breast conserving surgery alone, between 1982-2000. Histology was reviewed and immunohistochemical staining was preformed. Pearson correlation coefficient was used to determine the associations between markers and histopathological features. Univariate and multivariate analysis examined associations between time to recurrence and clinico-pathologic features and biological markers. Median age at diagnosis was 55 years (25-85). With a median follow up of 8.91 years, 41/133 patients recurred (21 as invasive recurrence). In this cohort 13.5% had low, 43% intermediate and 42% high nuclear grade. Comedo necrosis was found in 65% of cases. Expression of ER (62.4%), PR (55.6%), HER2/neu (31.6%), MIB1 (39.8%), p53 (22.6%), p21 (39.8%), Cyclin D1 (95.5%) calgranulin (20.5%), psoriasin (12%), was found in DCIS. HER2/neu was overexpressed in 45% that recurred as DCIS and 42.9% that recurred as invasive cancer, and only in 26.1% in cases that never recurred. On univariate analysis HER2/neu overexpression was the only marker associated with an increased risk for any recurrence (p=0.044). The hazard ratio for recurrence for HER2/neu positive DCIS was 1.927 (confidence interval 1.016-3.653) compared to HER2 negative DCIS. On multivariate analysis HER2/neu overexpression remained the only independent variable significantly associated with any recurrence (p=0.014) and with invasive recurrence (p=0.044). This data suggests that HER2/neu testing may become an important parameter in the management of DCIS and the treatment of cases with positive HER2/neu status could be modified accordingly, similar to the current approach for HER2/neu positive invasive disease. San Antonio Breast Cancer Symposium, 12/06 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.