Mutational landscape of endometrial cancer identified by prospective clinical sequencing in a nationwide cancer network.

Abstract

e17123 Background: Tumor genomic profiling is a critical component of precision oncology allowing the detection of genomic alterations (GA) that have the potential to be targeted therapeutically. We present an analysis of comprehensive genomic profiling (CGP) of a large series of endometrial cancer (EC) patients assayed in a nationwide cancer network. Methods: 278 Pts with advanced EC underwent CGP with hybrid capture of up to 406 cancer-related genes on tumor tissue or for 62 genes on circulating tumor DNA ordered during clinical care for treatment decision-making between 01-2013 to 05-2018. Clinically relevant genomic alterations (CRGA) were defined as associated with targeted therapies or mechanism-driven clinical trials. The treatment histories for these patients were obtained with IRB-approved retrospective review. Results: Median age was 59 years (range, 37-85), 58% were Caucasian. GA were identified in 97% (271/278) of EC, of which 218 (80%) had a clinically relevant genomic alteration (CRGA). PI3K/AKT/mTOR pathway ( PIK3CA, AKT1/2/3, PIK3R1, PTEN, MTOR, STK11, FBXW7) CRGA were most common, present in 63.8% of EC. CRGA in other targetable pathways were identified: 28.4% in MEK ( KRAS, NRAS, HRAS, BRAF, RAF1, GNAS, NF1, NF2) , 12.5% in HRD (BRCA1/2, ATM, PALB2, BRIP1 ) and 9.9% in ERBB ( ERBB2, ERBB3, ERBB4, EGFR). 26 patients are MSI-high 9.5% (26/271) and 21 patients are TMB-high 7.7% (21/271). 29.8% (65/218) of EC patients were ordered a genomically-matched treatment, and 61 of these patients received the treatment. 69.2% (45/65) were agents that were FDA approved in a different tumor type, and 24.6% (16/65) through referral to a matched mechanism driven clinical trial. With access to the clinical trial TAPUR, the frequency of matched treatment through clinical trials increased over time from 2013 to 2018. The median PFS for non-clinical trial study patients was 9 weeks, and the median OS was 27 weeks. Conclusions: In a large series of Endometrial and Uterine cancer patients assayed with CGP, 27.9% (61/218) of pts received matched treatment, which was predominantly targeted therapy. The comprehensive sensitive and unbiased nature of CGP, coupled with a multidisciplinary molecular tumor board and staff dedicated to genomic interpretation, assisted in achieving a high frequency of patients’ participation in clinical trials and gene-directed treatment.