Correlation of COX-2 Expression with Estrogen Receptor Status in DCIS
Y Hussein, S Bandyopadhyay, S Madan, T Jazaerly, K Hayek, B Albashiti, M Ibrahim, I Khalifeh, W Sakr, R Ali-Fehmi. Wayne State University, Detroit; American University of Beirut, Beirut, Lebanon
Background: Ductal carcinoma in situ (DCIS) continues to represent a growing proportion of patients diagnosed with mammary neoplasia in recent years. While DCIS is considered a major precursor to invasive carcinoma, the progression rates are believed to be variable and potentially related to multiple morphological and molecular markers. Our objective was to classify DCIS according to ER/ Her 2 Neu profile and the expression of COX-2 as a marker likely to signify higher progression potential.
Design: We identified 108 consecutive patients with DCIS on whom clinicopathological data and ER status were available. Immunohistochemical staining for Her 2 Neu and COX 2 was performed using standard procedures. ER was considered positive if > 10% of the nuclei were stained while > 30% of DCIS cells showing complete membrane staining was required for Her-2/neu positivity. The resulting four DCIS categories (ER+, Her2/neu-; ER+,HER2/neu+; ER-,Her2/NEU-; ER-, Her2/NEU+), were correlated with the linear model for COX2 expression levels (expressed as percentages) and with patients age, race and with DCIS nuclear grade. All data was analyzed using the R statistical environment.
Results: Of the 108 DCIS cases, 40 were ER+, Her 2/neu-; 5 were ER+, Her2/neu +; 8 were ER-, Her2/neu + and 2 were ER-, HER-2/neu-. Increased expression of COX-2 was seen in the ER -, Her2/neu + group when compared to the ER+, Her2/neu + group (p=0.004) and to the ER+, Her2/neu – group (p=0.0002). The small number of cases in the ER-, Her2/neu- group precluded the inclusion of this category in the statistical analysis. COX-2 expression did not correlate with patient age, race or DCIS nuclear grade.
Conclusions: Our data suggest that the morphologic heterogeneity of DCIS appeared to be mirrored on the ER, Her2neu status and COX-2 expression levels. The study indicates statistically significant correlation between COX-2 expression and non-hormonally driven DCIS as determined by Estrogen receptor negative status.
Tuesday, March 23, 2010 9:30 AM
Poster Session III # 45, Tuesday Morning