This work was accepted for an oral presentation at the ASCO Annual Meeting, Chicago, Illinois, 2012.
Molecular determinants of outcome with mammalian target of rapamycin inhibition in endometrial cancer
Article first published online: 25 OCT 2013
© 2013 American Cancer Society
Volume 120, Issue 4, pages 603–610, 15 February 2014
How to Cite
Mackay, H. J., Eisenhauer, E. A., Kamel-Reid, S., Tsao, M., Clarke, B., Karakasis, K., Werner, H. M. J., Trovik, J., Akslen, L. A., Salvesen, H. B., Tu, D. and Oza, A. M. (2014), Molecular determinants of outcome with mammalian target of rapamycin inhibition in endometrial cancer. Cancer, 120: 603–610. doi: 10.1002/cncr.28414
- Issue published online: 4 FEB 2014
- Article first published online: 25 OCT 2013
- Manuscript Accepted: 29 AUG 2013
- Manuscript Revised: 27 AUG 2013
- Manuscript Received: 24 MAY 2013
- endometrial cancer;
- predictive biomarkers;
Targeting the phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway is of increasing interest as a therapeutic strategy in many tumors. The aim of this study was to identify molecular markers associated with mTOR inhibitor activity in women with metastatic endometrial cancer.
Archival tumor samples were collected from 94 women with recurrent or metastatic endometrial cancer who participated in 3 National Cancer Insitute of Canada Clinical Trials Group phase 2 trials investigating single-agent mTOR inhibitors: IND160A and IND160B (temsirolimus) and IND192 (ridaforolimus). Analyses included mutational profiling using the OncoCarta Panel version 1.0 and immunohistochemical expression of the tumor suppressor gene PTEN (phosphatase and tensin homologue) and stathmin, a marker of PI3K activation. Associations between biomarker results and clinical outcomes were assessed.
Mutations were found in 32 of 73 analyzed tumors, PIK3CA (21 patients) was the most common mutated gene. Co-mutations were seen in 8 tumors, most frequently KRAS and PIK3CA (4 cases). PTEN loss was observed in 46 of 85 samples analyzed and increased stathmin expression was observed in 15 of 65 analyzed samples. No correlation was observed between biomarkers and response or progression. In patients taking concurrent metformin, there was a trend toward lower progression, of 11.8% versus 32.5% (P = .14).
No predictive biomarker or combination of biomarkers for mTOR inhibitor activity were identified in this study. Restriction and enrichment of study entry, especially based on archival tumor tissue, should be undertaken with caution in trials using these agents. Cancer 2014;120:603–610. © 2013 American Cancer Society.