Germline Testing identifies Pathogenic/Likely Pathogenic Variants in Patients with Pancreatic Neuroendocrine Tumors.

Abstract

10% of pancreatic neuroendocrine tumors (pNETs) are related to inherited syndromes (MEN1, MEN4, VHL, NF1, TSC). Growing evidence suggests that clinically sporadic pNETs can also harbor germline pathogenic variants. In this study, we report the prevalence of pathological/likely pathological germline variants (P/LP) in a high-risk cohort and an unselected cohort. We collected clinical data of patients with pNETs seen at MD Anderson Cancer Center (MDACC) and Johns Hopkins Hospital (JHH). High-risk cohort included (n=132) patients seen at MDACC who underwent germline testing for high-risk criteria (early onset, personal or family history of cancer and syndromic features) between 2013-2019. Unselected cohort (n=106) patients seen at JHH who underwent germline testing following their diagnosis of pNETs between 2020 to 2022. In the high-risk cohort (n=132), 33% (n=44) had P/LP variants. The majority of the patients had P/LP variants in MEN1 56% (n=25), followed by DNA repair pathways 18% (n=8), and 7 %(n=3) in MSH2 (Lynch Syndrome). Patients with P/LP were younger (45 years vs 50 years; p=0.002). In the unselected cohort (n=106), 21% (n=22) had P/LP. The majority were noted in DNA repair pathways 40% (n=9) and MEN1 36% (n=8). Multifocal tumors correlated with the presence of P/LP (p=0.0035). MEN1 germline P/LP variants correlated with younger age (40 vs 56 years) (p=0.0012). presence of multifocal tumors (p<0.0001), and WHO grade 1 histology (p=0.0078). P/LP variants are prevalent in patients with clinically sporadic pNET irrespective of high-risk features. The findings support upfront universal germline testing in all pNET patients.