Comparative molecular analyses of pancreatic cancer (PC): KRAS wild type vs. KRAS mutant tumors and primary tumors vs. distant metastases.

Authors

Mohamed Salem

Mohamed E. Salem

Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC

Mohamed E. Salem , John Marshall , Rebecca Feldman , Michael J. Pishvaian , Wafik S. El-Deiry , Jimmy J. Hwang , Emil Lou , Hongkun Wang , Zoran Gatalica , Sandeep K. Reddy , Anthony Frank Shields , Philip Agop Philip

Organizations

Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, Caris Life Sciences, Phoenix, AZ, Fox Chase Cancer Center, Philadelphia, PA, Department of Medicine and Oncology and Innovation Center for Biomedical Informatics, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, University of Minnesota, Hopkins, MN, Karmanos Cancer Institute, Detroit, MI

Research Funding

Other

Background: Targeted therapy has a minimal role in PC, partly because PC has not yet been well molecularly characterized. Little is known about the molecular characteristics of the subset of PC that doesn’t carry KRAS mutations. Better knowledge would enhance our ability to develop targeted therapies. Methods: PC tumors submitted to Caris Life Sciences for IHC (protein expression), ISH (gene amplification), and NGS sequencing between 2009 and 2015 were studied. Chi-square tests determined differences. Results: A total of 2426 PC tumors were examined. KRAS mutations (85%) were the most frequent genetic alteration. Other commonly mutated genes were TP53 (63%), SMAD4 (13%), BRCA2 (12%), ATM/APC/NTRK1 (5% each), BRCA1 (4%) and cMET/PIK3CA (3% each). BRAF mutations were seen in 6% of the RAS WT tumors. When compared with KRAS MT, KRAS WT tumors had a greater frequency of BRCA1 (9% vs. 3%, p = 0.05), CTNNB1 (5% vs. 0.2%; p < 0.01), GNAS (4% vs. 1.5%, p = 0.02), and FGFR2 (1.2% vs. 0.1%, p < 0.01) mutations, whereas SMAD4 and TP53 mutations were higher in KRAS MT tumors (15% vs. 5%, p = 0.02; 68% vs. 28%, p < 0.01, respectively). KRAS MT tumors had higher expression (66% vs. 49%, p < 0.01) and amplification (2.5% vs. 0%, p = 0.04) of cMET, and higher expression of EGFR (90% vs. 82%, p = 0.04), whereas KRAS WT tumors had higher HER2 expression (2% vs. 0.4%, p < 0.01) and amplification (6% vs. 0.7%, p < 0.01). Comparing 1o (n = 1099) with Met (n = 1327) PC, 1o tumors had a higher frequency of “low” ERCC1 (81% vs. 63%, p < 0.01) and “low” RRM1 (87% vs. 77%, p < 0.01), and higher PD1+ TILs (45% vs. 34%, p < 0.01). Conversely, cMET (62% vs. 51%, p = 0.006), PDL1 (10% vs. 5%, p = 0.01), and TOPO1 (65 vs. 33, p < 0.01) were overexpressed at higher rates in Met PC. Lung Mets, had a higher expression of HER2 (2.3% vs. 0.5%; < 0.01), and PD1 TILs (50% vs. 33%; p = 0.03) than liver Mets, whereas, the PIK3CA mutation rate was higher in liver Mets (4% vs. 0%; p = 0.03). Conclusions: Genomic differences between KRAS WT vs. MT tumors suggest different carcinogenic pathways and tumor biology. 1o tumors may carry genetic alterations that are distinct from distant Mets. Mutations in druggable genes (e.g., HER-2, PIK3CA, BRCA2) may provide therapeutic opportunities.

Disclaimer

This material on this page is ©2024 American Society of Clinical Oncology, all rights reserved. Licensing available upon request. For more information, please contact licensing@asco.org

Abstract Details

Meeting

2016 ASCO Annual Meeting

Session Type

Poster Session

Session Title

Gastrointestinal (Noncolorectal) Cancer

Track

Gastrointestinal Cancer—Gastroesophageal, Pancreatic, and Hepatobiliary

Sub Track

Pancreatic Cancer

Citation

J Clin Oncol 34, 2016 (suppl; abstr 4121)

DOI

10.1200/JCO.2016.34.15_suppl.4121

Abstract #

4121

Poster Bd #

113

Abstract Disclosures

Similar Abstracts

Abstract

2023 ASCO Gastrointestinal Cancers Symposium

Circulating tumor DNA–based genomic landscape of KRAS wild-type pancreatic adenocarcinoma.

First Author: Brendon Fusco

Abstract

2023 ASCO Annual Meeting

Relations between mutant KRAS and TP53 subtypes and other co-mutations in pancreatic cancer.

First Author: Soniya Abraham

Abstract

2020 ASCO Virtual Scientific Program

Enrichment of alterations in targetable molecular pathways in KRAS wild-type (WT) pancreatic cancer (PC).

First Author: Philip Agop Philip

Abstract

2023 ASCO Annual Meeting

The clinical and genomic characteristics of KRAS G12D mutated cancers.

First Author: Guomin Lin