The impact of germline and somatic mutations in the homologous recombination repair pathway in pancreatic cancer patients who undergo perioperative chemotherapy.

Authors

Gudbjorg Jonsdottir

Gudbjorg Jonsdottir

University of Iowa Hospitals and Clinics, Iowa City, IA

Gudbjorg Jonsdottir , Asgeir Thor Masson , Laura S. Jacobus , Michelle L. Churchman , Stephen B. Edge , Anne M. Noonan , Michael J. Cavnar , Susanna Varkey Ulahannan , Ibrahim Halil Halil Sahin , Carlos Hou Fai Chan

Organizations

University of Iowa Hospitals and Clinics, Iowa City, IA, University of Iowa, Iowa City, IA, M2Gen, Tampa, FL, Roswell Park Comprehensive Cancer Center, Buffalo, NY, The Ohio State University Comprehensive Cancer Center, Arthur G. James Cancer Hospital, Columbus, OH, University of Kentucky, Lexington, KY, Stephenson Cancer Center, Oklahoma City, OK, 1574, Atlanta, GA, Brigham and Women's Hosp, Brookline, MA

Research Funding

No funding received

Background: Limited data is available regarding the effects of germline and somatic mutations in the homologous recombination repair (HRR) pathway in patients with resectable pancreatic cancer and exactly which mutations can be targeted with platinum-based chemotherapy. We aimed to assess the impact of HRR pathway mutations in a large cohort of pancreatic patients who underwent curative intent surgical resection. Methods: Patients with resectable pancreatic cancer who underwent perioperative chemotherapy, diagnosed from 1999-2020 from the participating members of the Oncology Research Information Exchange Network (ORIEN) were included in the study. Patients with germline and somatic whole exome sequencing data were analyzed for known pathogenic and likely pathogenic variants according to ClinVar in the following HRR pathway genes: BRCA1, BRCA2, PALB2, BRIP1, BRAD1, ATM, RAD51C, RAD51, RAD50, CHECK2, FANCC, FANCA, MRE11 and XRCC2. The Kaplan Meier method was used to compare median overall survival (OS) between patients with adenocarcinoma, with and without HRR pathway mutations. Multivariate cox proportional hazard model was used to calculate HR and 95% CI adjusting for age at diagnosis, sex and pathologic stage. Results: During the study period, the ORIEN cohort included 417 patients with resectable pancreatic cancer and whole exome sequencing. Of these 313 (75%) patients had adenocarcinoma and 104 (25%) neuroendocrine tumor. A total of 19 patients (5%) had an HRR pathway mutation - 15 (5%) in the adenocarcinoma group and 4 (4%) in the neuroendocrine group. In the adenocarcinoma group, 97 (31%) patients underwent platinum-based perioperative chemotherapy. Median OS was 2.8 years (IQR 2.5-3.3) in the adenocarcinoma group without HRR pathway mutation and 3.8 years (IQR 3.4-NA) in the group with HRR pathway mutation (HR 0.6: 95% CI 0.3-1.4, p = 0.76). Conclusions: There was a trend towards improved survival in patients with adenocarcinoma receiving perioperative platinum-based chemotherapy with HRR pathway mutations compared to those without a mutation. This finding supports previous data in the literature regarding the prognostic role of HRR pathway alterations in pancreatic cancer. Larger prospective studies are needed to assess the predictive role of these mutations in the perioperative setting in response to platinum-based chemotherapy.

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Abstract Details

Meeting

2022 ASCO Gastrointestinal Cancers Symposium

Session Type

Poster Session

Session Title

Poster Session B: Cancers of the Pancreas, Small Bowel, and Hepatobiliary Tract

Track

Pancreatic Cancer,Hepatobiliary Cancer,Neuroendocrine/Carcinoid,Small Bowel Cancer

Sub Track

Tumor Biology, Biomarkers, and Pathology

DOI

10.1200/JCO.2022.40.4_suppl.602

Abstract #

602

Poster Bd #

Online Only

Abstract Disclosures