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PURPOSE Evidence-based guidelines recommend cascade genetic counseling and testing for hereditary cancer syndromes, providing relatives the opportunity for early detection and prevention of cancer. The current standard is for patients to contact and encourage relatives (patient-mediated contact) to undergo counseling and testing. Direct relative contact by the medical team or testing laboratory has shown promise but is complicated by privacy laws and lack of infrastructure. We sought to compare outcomes associated with patient-mediated and direct relative contact for hereditary cancer cascade genetic counseling and testing in the first meta-analysis on this topic. MATERIALS AND METHODS We conducted a systematic review and meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO No.: CRD42020134276). We searched key electronic databases to identify studies evaluating hereditary cancer cascade testing. Eligible trials were subjected to meta-analysis. RESULTS Eighty-seven studies met inclusion criteria. Among relatives included in the meta-analysis, 48% (95% CI, 38 to 58) underwent cascade genetic counseling and 41% (95% CI, 34 to 48) cascade genetic testing. Compared with the patient-mediated approach, direct relative contact resulted in significantly higher uptake of genetic counseling for all relatives (63% [95% CI, 49 to 75] v 35% [95% CI, 24 to 48]) and genetic testing for first-degree relatives (62% [95% CI, 49 to 73] v 40% [95% CI, 32 to 48]). Methods of direct contact included telephone calls, letters, and e-mails; respective rates of genetic testing completion were 61% (95% CI, 51 to 70), 48% (95% CI, 37 to 59), and 48% (95% CI, 45 to 50). CONCLUSION Most relatives at risk for hereditary cancer do not undergo cascade genetic counseling and testing, forgoing potentially life-saving medical interventions. Compared with patient-mediated contact, direct relative contact increased rates of cascade genetic counseling and testing, arguing for a shift in the care delivery paradigm, to be confirmed by randomized controlled trials.

The literature demonstrates that the quality of cancer family history (CFH) as currently collected in the outpatient setting is inadequate to assess disease risk. Prior to implementation of a web-based application for cancer family history collection, we aimed to review the quality of collected CFH in a gynecologic oncology outpatient clinic and determine contributing patient factors. Medical records were reviewed for 200 new patients presenting between 4/2019-7/2019. CFH was collected during the patient interview and evaluated for inclusion of eight elements based on standards set by the genetics community. Univariate and multivariable linear regression analyses were utilized to evaluate the effect of patient characteristics on the number of relatives included in the CFH. Among our cohort of 200 patients, CFH was documented for 185 patients (92.5%). On univariate analysis, patients with a family history of cancer and prior genetic testing had significantly greater median number of relatives included in the CFH. On multivariable analysis, patients with family members with cancer had significantly more relatives included. Our data are consistent with the literature, suggesting that the current collection methods may not adequately capture all measures of a high quality CFH. Patients reporting no family history of cancer and those without prior genetic testing were least likely to have CFH that included key quality elements and these patients might benefit from health information technology CFH collection tools.

e17597 Background: Approximately 20% of ovarian cancers are due to an underlying germline pathogenic variant. While several genes have been well-established in the development of hereditary ovarian cancer (e.g. BRCA1/2, RAD51C, RAD51D, BRIP1, mismatch repair genes), there are other genes for which the cancer risk is less certain and management recommendations remain controversial, including partner and localizer of BRCA 2 (PALB2). We sought to evaluate the association between PALB2 germline pathogenic mutations and ovarian cancer in the first meta-analysis on this topic. Methods: We conducted a systematic review and meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO no.: CRD42021281325). We searched key electronic databases to identify studies evaluating multigene panel testing in patients with ovarian cancer. Eligible trials were subjected to meta-analysis. Results: Thirty-seven studies met inclusion criteria. We found 55,137 cases of ovarian cancer with information available on germline PALB2 pathogenic variant status. Reported histological subtypes included serous adenocarcinoma (74.8%), endometroid (6.5%), clear cell (2.1%), mucinous (3.1%), and other (13.5%). Most ovarian cancers were stages III (73.5%) and IV (22.3%), followed by II (6.0%), and I (4.1%). Among ovarian cancer cases with PALB2 sequencing data available, 0.4% demonstrated a germline pathogenic variant in the PALB2 gene and the pooled odds ratio (OR) for having a PALB2 mutation was 2.31 (95% CI 0.89- 5.98). Among 94 patients with a germline PALB2 pathogenic variant, the pooled odds ratio (OR) for developing ovarian cancer was 2.85 (95% CI 1.58-5.15) relative to 33,855 patients without PALB2 mutations. Conclusions: Our meta-analysis demonstrates that the pooled OR for developing ovarian cancer with an underlying PALB2 germline pathogenic variant was 2.85 (95% CI 1.58-5.15). While this risk is lower than many of the well-established hereditary ovarian cancer genes, it does exceed the baseline population risk of 1-2%. Whether this meets the threshold to consider risk-reducing salpingo-oophorectomy is up for debate. Large population-based studies and evaluation of the combination of PALB2 mutations and cancer family history are needed to improve management recommendations for patients harboring pathogenic mutations in this gene.

10592 Background: Evidence-based guidelines recommend that patients (probands) diagnosed with a hereditary cancer syndrome share the information with blood relatives as relatives can have 50% risk for harboring the same pathogenic mutation. This information offers the opportunity for relatives to undergo genetic counseling, genetic testing, early detection, and prevention of cancer. Limited literature on this topic suggests underutilization of recommended family member disclosure. We sought to evaluate rates of familial disclosure of hereditary cancer syndrome information in the first meta-analysis on this topic. Methods: We conducted a systematic review and meta-analysis in accordance with PRISMA guidelines (PROSPERO no.: CRD42020134276). We searched key electronic databases to identify studies evaluating hereditary cancer cascade relative disclosure. Eligible trials were subjected to meta-analysis. Results: Thirty studies met inclusion criteria. This review included 3,779 probands and 12,751 at-risk relatives. Among 12,751 included relatives, 72% (CI 64-79%) received information about the hereditary cancer syndrome identified in their family and 28% (CI 19-37%) underwent genetic testing. On meta-analysis, there was a higher rate of disclosure among female vs male relatives (79% [73% - 84%] vs 67% [57% - 75%]) and a higher rate among first-degree vs. second degree relatives (83% [77% - 88%] vs 58% [45 – 69%]). The data regarding the contribution of race/ethnicity to disclosure were limited and inconsistent, with two studies demonstrating non-White vs. White relatives being less likely to have results disclosure and two studies finding no correlation; however, both studies finding no difference were limited by small sample sizes. Finally, one study found that higher proband annual income was associated with improved familial disclosure. Conclusions: Despite a growing understanding of the importance of cascade genetic counseling and testing, probands do not disclosure information on hereditary cancer syndromes to most at-risk relatives. Very few relatives complete genetic testing, representing a critical missed opportunity for precision cancer prevention. Future studies are needed to elucidate barriers to hereditary cancer syndrome disclosure and create innovative strategies to facilitate this essential process.