Abstract ES8-2: Prognostic indicators in treatment of DCIS

Abstract

Abstract The goal of DCIS treatment is to avoid a future invasive breast cancer. Invasive breast cancer risk is heterogeneous across the population of DCIS patients. More than 40% of women with minimal, low grade DCIS will develop invasive breast cancer if left untreated and followed for more than 10 years. Risk of invasive recurrence is about 2% per year for DCIS treated by simple excision (lower for small low grade lesions and higher for larger high grade lesions). A reliable approach for risk-stratifying individual DCIS lesions could permit tailored approaches to therapy or avoidance of therapy all together in the lowest risk women. Screen-detected, grade 1 and 2 micropapillary DCIS in older women is likely the lowest risk lesion. Progression to invasive breast cancer is more likely related to focal myoepithelial cell dysfunction than molecular alterations in the bulk luminal cell populations. Nevertheless, p16, ER, COX2, HER-2/neu, and Ki67 staining patterns in the bulk luminal cell population have been linked to recurrence risk. A 12 gene recurrence score has been shown to predict the risk of recurrence for DCIS treated by excision without radiation. This assay was adapted from the 21-gene OncoTypeDx test and is weighted heavily towards proliferation markers. Accurate prediction of invasive recurrence risk will likely require detection of focal alterations in myopeithelial cells and the basement membrane. Citation Format: Euhus DM. Prognostic indicators in treatment of DCIS. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES8-2.