A comprehensive program may improve access to effective genetic counseling services in patients with ovarian and breast cancer despite geographic barriers.

676 Background: Results from the POLO trial demonstrated the benefits of PARP inhibition in patients (pts) with germline BRCA-mutated metastatic pancreatic cancer (PC). In 2018, ASCO and NCCN updated their guidelines to recommend that pts with a personal history of PC undergo germline testing. We examined referral patterns and frequency of germline pathogenic variants in pts with PC. Methods: A retrospective review was performed of PC pts seen at the Levine Cancer Institute (LCI) Center for Genetics between January 2010 and September 2019. Descriptive analyses were completed on demographics and appointment outcomes. Results: A total of 201 PC pts were referred; 20 canceled and 14 no-showed their appointment. The remaining 167 were seen and included in this analysis. Most pts (59%) were referred after July 2018. The median age was 65 years (range 32-90) and 19% were < 50 years. The majority of pts were female (61%). Race was most often reported as white (72%) followed by black (20%). Reported family histories were as follows: 28 (17%) claimed at least one first-degree relative with PC; 54 (32%) claimed a first, second, or third-degree relative with PC; 24 (14%) had no known family history of PC; and 95 (57%) claimed a first-degree relative with another cancer (breast [37], prostate [25], colon [18], ovarian [9], uterine [6], and gastric [2]). Germline testing was pursued by 138 (83%) pts: 25 (18%) were found to have a pathogenic variant and 50 (36%) a variant of uncertain significance. Pathogenic variants were most commonly identified in ATM (24%), BRCA2 (20%), PALB2 (12%), and CDKN2A (8%). Variants were also observed in DIS3L2, HOXB13, MITF, MUTYH (heterozygote), NTHL1 (compound heterozygote), RAD50, PRSS1, and SDHA. Among pts that had a pathogenic variant, cascade testing was performed in 11 families (44%) for 29 individuals. Conclusions: Our data suggest that the referral of PC pts to genetics has increased following updated ASCO/NCCN guidelines. However, improved adherence to genetic counseling is needed. ATM and BRCA2 were the most common germline mutations observed. More effort to increase awareness of genetic testing and its potential implications for pts and their families is warranted and might reduce cancellations and missed visits.

e13660 Background: The efficacy of PARP inhibitors in germline BRCA-mutated pancreatic adenocarcinoma (PC) and immune checkpoint inhibitors in dMMR colorectal cancer (CRC) shows the importance of genetic testing. We aimed to characterize the frequency of pathogenic/likely pathogenic germline variants (PLPVs) in GI cancer pts. Methods: A retrospective review of pts referred to the Levine Cancer Institute Genetics Program was conducted. Genetic testing used a focused hereditary cancer 4-43 gene panel or pan-cancer 82-84 gene panel. Results: Out of 1144 GI cancer pts seen between 2010 and 2019, 869 underwent germline testing, and 199 (23%) pts had at least one PLPV in a hereditary cancer susceptibility gene, while 253 (29.3%) had a variant of uncertain significance. Of 630 CRC pts, 24% had a PLPV and 13% harbored a germline mutation in DNA MMR genes and were diagnosed with Lynch Syndrome, representing ~50% of all pts with a PLPV. Other germline PLPVs were found in APC, ATM, BRCA1, BRCA2, CHEK2, MUTYH, and PALB2. Of 163 PC pts, 16.6% had a PLPV in ATM, BRCA2, CDKN2A, and MEN1. Gastric cancer pts (17%) had germline PLPVs in APC, BRCA2, CDH1, MLH1, and MSH2; biliary cancer pts (17%) had germline PLPVs in PALB2, RAD50, and PTCH1; and GIST pts (60%) had PLPVs in SDHA or SDHB. Conclusions: Germline mutations were found in 23% of GI cancer pts, underlining the importance of multigene germline testing. Knowledge of inherited GI cancer risk helps determine the likelihood of benefit from possible specific targeted therapies. Genetic testing and counseling pose a challenge, but implications for pts with hereditary syndromes are highly significant. [Table: see text]

e16300 Background: EOPC is associated with significant life years lost. Approximately 5%-10% of pancreatic adenocarcinoma (PAC) have an underlying genetic predisposition and national guidelines recommend testing in all patients with PAC. Certain germline mutations such as BRCA2 and PALB2 predict response to specific treatments including platinum and targeted therapies. It is currently unknown to what extent patients with EOPC pursue recommended germline testing. We examined the utilization of germline testing in patients with EOPC who were referred to genetics. Methods: A retrospective review of patients with EOPC at the Levine Cancer Institute (LCI), defined as ≤60 years of age at time of diagnosis, who were referred and seen by genetics between January 2019 and December 2021 was performed. Germline testing was performed using multi-gene cancer panels. Positive germline testing was considered as any known pathogenic or likely pathogenic variant not including variants of unknown significance (VUS). Results: We identified 69 patients with EOPC who were evaluated by genetics. The median age was 55 years (range 25-60) with 36 (52%) male, 33 (48%) female, 48 (70%) white, 16 (23%) Black, 61 (89%) with ECOG 0-1, 36 (52%) current or prior smoking history, and 28 (42%) presenting with metastatic disease. As shown, out of 69 patients, 10 (14%) declined testing or had unknown results, 30 (43%) had negative germline testing, 29 (42%) had genetic testing that revealed 19 (65%) had VUS, and 10 (34%) had pathogenic variants. The most frequently seen pathogenic variants were ATM (30%), BRCA1 (30%), BRCA2 (10%), MLH1 (10%), RAD51C+ (10%) and CFTR (10%). Conclusions: Our data suggest that most patients with EOPC who are evaluated undertake germline testing. Given the predictive nature of certain pathogenic mutations on PAC treatment options, characteristics of patients with EOPC who decline testing should be further explored. There is need for larger studies to confirm the high incidence of pathogenic variants observed in our cohort of EOPC patients. [Table: see text][Table: see text]