Microsatellite instability and loss of PTEN expression in early versus late-stage endometrial cancer: Results from studies of the National Cancer Institute of Canada Clinical Trials Group (NCIC-CTG)

• DOI: 10.1200/jco.2009.27.15_suppl.5534
• Publication Date: 2020-08-25T20:11:01Z
• Authors: H. Mackay; S. Gallinger; M. Tsao; C. M. McLachlin; K. Kieser; E. Eisenhauer; D. Tu; A. Oza
• Keywords: Microsatellite Instability; Univariate analysis

5534 Background: Microsatellite instability (MSI+) and inactivation of the tumor suppressor gene PTEN are implicated in development endometrial cancer (EC). The aim this study was to compare prognostic value MSI 2 patient (pt) populations, early stage vs. advanced/recurrent disease. Methods: Archival paraffin embedded from pts with EC enrolled closed NCIC-CTG studies: I/II (EN5) disease(IND 126, 148 160) were examined for (BAT 25/26) expression (immunohistochemistry). status correlated clinicopathologic features outcome trial databases. Results: 188 pt samples (97 I/II;91 disease) examined. Results available 129 166 pts. Overall, 55% negative (-) 19.3% MSI+. 33 (56.9%) - EN5 38 (53.5%) IND studies (p = 0.73). no association seen between or age, performance (PS), grade histology. In univariate analysis, there a trend towards improved survival (S) (HR 0.61; 95% CI, 0.36 -1.04, p 0.07), weaker multivariate analysis 0.56; 0.26–1.18 0.12). EN5, not associated S uni-or analyses. 0.57; 0.32–1.06 0.07). More MSI+ 23 (27.4%) studies, 9 (11%) 0.01. microsatellite stable (MSS) tumors better prognosis both 0.18; 0.06–0.51, < 0.0001) 0.16; 0.05 0.5, 0.0001). There difference MSS overall, studies. uni- correlation overall either group Conclusions: more common, worse prognosis, EC. is PTEN- advanced status. No significant financial relationships disclose.