Background: Pancreatic ductal adenocarcinoma (PDAC) is associated with a significant percentage of germline pathogenic variants (GPVs). Unlike in the United States, routine universal genetic testing is not performed in Europe. The aim of the study is to evaluate the diagnostic yield of germline genetic testing in all patients with PDAC.
Methods: Individuals with newly diagnosed PDAC from three Spanish hospitals were enrolled, regardless of family history. Thirteen known susceptibility genes for PDAC were studied using a multigene panel or whole-exome sequencing.
Results: One hundred seventy-nine PDAC patients underwent genetic testing. Fourteen (7.8%) had a GPV or likely pathogenic variant In the genes studied: six in ATM, six in BRCA2, one in PALB2, and one in TP53. Of these, seven (50%) did not meet the clinical criteria for genetic study and would have been classified as sporadic PDAC. Presenting with a personal history of any other neoplasm was associated with some GPV, with an odds ratio (OR) of 3.5 (1.1-11.5). A family history of PDAC and breast cancer was also associated with some GPV, with oRs of 3.7 (1.08-13.6) and 8.5 (2.6-26.6), respectively. None of the patients over 60 years without a relevant family history of malignancies presented a GPV associated with PDAC.
Conclusions: In our PDAC cohort, a noteworthy number of GPVs were identified, and half of these patients would have been classified as sporadic based solely on clinical criteria. Genetic testing should always be considered, particularly in patients under 60 years or those with a history of other malignancies, especially where economic resources need optimization.
Keywords: genetic testing; germline pathogenic variant; pancreatic cancer.