Abstract
Abstract Introduction: ALK mutations are one of the most common genetic aberrations occurring in 3-11% of the neuroblastoma (NBL) patients and are considered oncogenic. We determined the role of ALK protein levels on survival of NBL patients. Secondly, we tested in vitro responsiveness to ALK inhibitors in NBL cell lines with and without ALK mutation. Results: Formalin-Fixed, Paraffin-Embedded material of 71 NBL, 12 ganglioneuroblastoma (GNBL) and 20 ganglioneuroma (GN) patients was stained for total ALK protein by immunohistochemistry (IHC). The percentage of ALK positive cells in IHC was stratified in 4 Ccategories; Category 1 (n=40): < 20% ALK-positive cells, category 2 (n=25): 20-50% ALK positive cells, category 3 (n=25): 50-75% ALK positive cells, and category 4 (n=13): 75-100% ALK positive cells. These categories correlate significantly with overall survival in the spectrum of NBL, GNBL and GN (p=0.002, Logrank test). ALK mutations were identified in 2/63 NBL (3.2%) and 2/11 GNBL (18.2%) patients by sequencing. Importantly, in NBL and GNBL patients, ALK protein expression remains a significant factor in a multivariate model (Cox Proportional Hazard model) including the COG risk stratification (p<0.000), which encompasses stage and NMYC status (see table). Further, we studied the role of ALK levels in the response to ALK inhibitors in vitro in NBL cell lines. ALK inhibitor response (TAE684) correlates well with ALK protein levels (r=−0.813, p=0.001). ALK point mutated cell lines show higher ALK levels and a better ALK inhibitor response (LC50 values 14.9 fold lower, p=0.004) than WT and amplified cell lines. In conclusion: ALK protein expression is an independent predictor of overall survival in NBL patients and ALK inhibitor response in vitro. ICH staining with ALK antibody is reliable and correlates well with prognosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4347. doi:10.1158/1538-7445.AM2011-4347
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
