Garber, Judy E.

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic provide recommendations for genetic testing and counseling for hereditary cancer syndromes, and risk management recommendations for patients who are diagnosed with syndromes associated with an increased risk of these cancers. The NCCN panel meets at least annually to review comments, examine relevant new data, and reevaluate and update recommendations. These NCCN Guidelines Insights summarize the panel’s discussion and most recent recommendations regarding criteria for high-penetrance genes associated with breast and ovarian cancer beyond BRCA1/2 , pancreas screening and genes associated with pancreatic cancer, genetic testing for the purpose of systemic therapy decision-making, and testing for people with Ashkenazi Jewish ancestry.

AbstractPrevious transcriptome‐wide association studies (TWAS) have identified breast cancer risk genes by integrating data from expression quantitative loci and genome‐wide association studies (GWAS), but analyses of breast cancer subtype‐specific associations have been limited. In this study, we conducted a TWAS using gene expression data from GTEx and summary statistics from the hitherto largest GWAS meta‐analysis conducted for breast cancer overall, and by estrogen receptor subtypes (ER+ and ER−). We further compared associations with ER+ and ER− subtypes, using a case‐only TWAS approach. We also conducted multigene conditional analyses in regions with multiple TWAS associations. Two genes, STXBP4 and HIST2H2BA, were specifically associated with ER+ but not with ER– breast cancer. We further identified 30 TWAS‐significant genes associated with overall breast cancer risk, including four that were not identified in previous studies. Conditional analyses identified single independent breast‐cancer gene in three of six regions harboring multiple TWAS‐significant genes. Our study provides new information on breast cancer genetics and biology, particularly about genomic differences between ER+ and ER− breast cancer.

Abstract Background The purpose of this study was to estimate precise age-specific tubo-ovarian carcinoma (TOC) and breast cancer (BC) risks for carriers of pathogenic variants in RAD51C and RAD51D. Methods We analyzed data from 6178 families, 125 with pathogenic variants in RAD51C, and 6690 families, 60 with pathogenic variants in RAD51D. TOC and BC relative and cumulative risks were estimated using complex segregation analysis to model the cancer inheritance patterns in families while adjusting for the mode of ascertainment of each family. All statistical tests were two-sided. Results Pathogenic variants in both RAD51C and RAD51D were associated with TOC (RAD51C: relative risk [RR] = 7.55, 95% confidence interval [CI] = 5.60 to 10.19; P = 5 × 10-40; RAD51D: RR = 7.60, 95% CI = 5.61 to 10.30; P = 5 × 10-39) and BC (RAD51C: RR = 1.99, 95% CI = 1.39 to 2.85; P = 1.55 × 10-4; RAD51D: RR = 1.83, 95% CI = 1.24 to 2.72; P = .002). For both RAD51C and RAD51D, there was a suggestion that the TOC relative risks increased with age until around age 60 years and decreased thereafter. The estimated cumulative risks of developing TOC to age 80 years were 11% (95% CI = 6% to 21%) for RAD51C and 13% (95% CI = 7% to 23%) for RAD51D pathogenic variant carriers. The estimated cumulative risks of developing BC to 80 years were 21% (95% CI = 15% to 29%) for RAD51C and 20% (95% CI = 14% to 28%) for RAD51D pathogenic variant carriers. Both TOC and BC risks for RAD51C and RAD51D pathogenic variant carriers varied by cancer family history and could be as high as 32–36% for TOC, for carriers with two first-degree relatives diagnosed with TOC, or 44–46% for BC, for carriers with two first-degree relatives diagnosed with BC. Conclusions These estimates will facilitate the genetic counseling of RAD51C and RAD51D pathogenic variant carriers and justify the incorporation of RAD51C and RAD51D into cancer risk prediction models.

TPS779 Background: 4-10% of PDAC patients harbor pathogenic germline variants in cancer susceptibility genes, including APC, ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, and TP53. For families with such pathogenic variants, the greatest potential impact of germline testing is to identify relatives with the same variant (cascade testing), thereby providing the opportunity for early detection and interception of PDAC and other associated cancers. Numerous factors limit cascade testing in real-world practice, including family dynamics, widespread geographic distribution of relatives, access to genetic services, and misconceptions about the importance of germline testing, such that the preventive benefits of cascade testing are often not fully realized. The primary aim of this study is to analyze two alternative strategies for cascade testing in families with inherited PDAC risk. Methods: 1000 individuals with a confirmed pathogenic germline variant in any of the above genes in a 1st/2nd degree relative and a 1st/2nd degree relative with PDAC will be remotely enrolled through the study website (www.GENERATEstudy.org) and randomized between two methods of cascade testing (individuals with prior genetic testing will be ineligible): Arm 1 will undergo pre-test genetic education with a pre-recorded video and live interactive session with a genetic counselor via a web-based telemedicine platform (Doxy.me), followed by germline testing through Color Genomics; Arm 2 will undergo germline testing through Color Genomics without dedicated pre-test genetic education. Color Genomics will disclose results to study personnel and directly to participants in both arms. All participants will have the option of pursuing additional telephone-based genetic counseling through Color Genomics. The primary outcome will be uptake of cascade testing. Secondary outcomes will include self-reported genetic knowledge, cancer worry, distress, decisional preparedness, familial communication, and screening uptake, which will be measured via longitudinal surveys. Enrollment is underway nationwide as of May, 2019. Clinical trial information: NCT03762590.

PURPOSETo estimate age-specific relative and absolute cancer risks of breast cancer and to estimate risks of ovarian, pancreatic, male breast, prostate, and colorectal cancers associated with germline PALB2 pathogenic variants (PVs) because these risks have not been extensively characterized.METHODSWe analyzed data from 524 families with PALB2 PVs from 21 countries. Complex segregation analysis was used to estimate relative risks (RRs; relative to country-specific population incidences) and absolute risks of cancers. The models allowed for residual familial aggregation of breast and ovarian cancer and were adjusted for the family-specific ascertainment schemes.RESULTSWe found associations between PALB2 PVs and risk of female breast cancer (RR, 7.18; 95% CI, 5.82 to 8.85; P = 6.5 × 10−76), ovarian cancer (RR, 2.91; 95% CI, 1.40 to 6.04; P = 4.1 × 10−3), pancreatic cancer (RR, 2.37; 95% CI, 1.24 to 4.50; P = 8.7 × 10−3), and male breast cancer (RR, 7.34; 95% CI, 1.28 to 42.18; P = 2.6 × 10−2). There was no evidence for increased risks of prostate or colorectal cancer. The breast cancer RRs declined with age ( P for trend = 2.0 × 10−3). After adjusting for family ascertainment, breast cancer risk estimates on the basis of multiple case families were similar to the estimates from families ascertained through population-based studies ( P for difference = .41). On the basis of the combined data, the estimated risks to age 80 years were 53% (95% CI, 44% to 63%) for female breast cancer, 5% (95% CI, 2% to 10%) for ovarian cancer, 2%-3% (95% CI females, 1% to 4%; 95% CI males, 2% to 5%) for pancreatic cancer, and 1% (95% CI, 0.2% to 5%) for male breast cancer.CONCLUSIONThese results confirm PALB2 as a major breast cancer susceptibility gene and establish substantial associations between germline PALB2 PVs and ovarian, pancreatic, and male breast cancers. These findings will facilitate incorporation of PALB2 into risk prediction models and optimize the clinical cancer risk management of PALB2 PV carriers.

Background: Lymphoma patients exposed to chest RT during adolescence/young adulthood are at increased risk for BC; the cumulative incidence exceeds 20% by age 45 and the BC risk is comparable to that in women with BRCA1 mutations. These findings present an urgent yet unmet need to reduce the risk of BC in RT-exposed lymphoma survivors. The risk of BC is 50% lower in chest RT-exposed survivors who also receive ovarian radiation, suggesting a critical role of endogenous estrogens in RT-related breast carcinogenesis, making tamoxifen (a selective estrogen receptor modulator) an attractive risk-reducing option. Tamoxifen administered at 20 mg/d is effective in BC prevention in other high risk populations, but severe adverse events (SAE: venous thromboembolism, endometrial cancer) have limited its broad use. Previous biomarker trials in the general population have shown that LDTam (5mg/d) is not inferior to tamoxifen at 20 mg/d in reducing BC risk, and is associated with a safer AE profile. Mammographic breast density (MBD) is an established biomarker of BC risk; high MBD is associated with a 4-fold higher risk of BC. We hypothesized that LDTam would be effective in reducing BC risk (using MBD as a primary endpoint) in chest RT-exposed lymphoma survivors. We used an investigator-initiated, multi-institutional, randomized phase IIb, double blind, placebo controlled trial (FDA IND 107367) to test this hypothesis. Methods: Female patients from 13 sites were ≥25y at enrollment, with a history of exposure to chest RT at ≥12 Gy by age 40 for their primary cancer, and were off therapy for ≥6 mo. Subjects with a prior history of BC/DCIS, B/L mastectomy, or baseline MBD <25% in both breasts were excluded. Tamoxifen 5mg or identical placebo tablets were provided by Sharp Clinical Services (Allentown, PA) under good manufacturing practice. Subjects were randomized 1:1 in a double-blinded fashion by a Web-based system to receive LDTam or placebo daily for 2y. MBD (in both breasts) was measured centrally on digital scans independently by 3 radiologists at baseline, 1y and 2y. Using an intention-to-treat analysis, the efficacy of LDTam in reducing MBD was compared between the LDTam and placebo arms by applying a linear mixed effects model for bivariate normally distributed data with random intercept and time*treatment arm effects. Correlations between the left and right breasts and within radiologists were accounted for in the model. Treating clinicians and all research staff were blinded to the treatment arm. Results: A total of 72 patients (LDTam: n=34; placebo: n=38) participated in the trial; primary diagnosis: Hodgkin lymphoma (86%); non-Hodgkin lymphoma (10%); other (3%); median age at diagnosis of primary cancer: 21.5y (IQR, 16-28), and at trial enrollment: 43.8y (35-49); median time from diagnosis of primary cancer to study: 17.0y (12-26). Median chest RT dose: 30.3 Gy (21-37.3); 11% had received pelvic radiation; 39% were post-menopausal at study. Participant characteristics were comparable between the two treatment arms, as was the mean baseline MBD (LDTam: 52.6% vs. placebo: 50.4%, p=0.6). The time*treatment arm effect was statistically significant (LDTam vs. placebo: estimate = -1.7, SE = 0.5, p = 0.001), indicating a significantly lower mean fitted MBD for LDTam (43.9%) vs. placebo (47.3%) at 2y (Figure). This represented a 16.5% relative reduction in MBD on the LDTam arm, corresponding to an estimated 33% lower risk of BC (assuming that reductions in MBD have the same benefit in lymphoma survivors as they do in the general population). There were no grade 3 or 4 AEs related to LDTam. Grade 2 AEs did not differ between treatment arms (LDTam: 44.1% vs. placebo: 36.8%, p=0.6). There was no difference in the prevalence of moderate-to-severe patient-reported outcomes between the treatment arms (Table). Conclusion: Low-dose tamoxifen was associated with a significantly steeper decline in MBD in chest RT-exposed lymphoma survivors, when compared with placebo, and was safe and well-tolerated. This is the first trial demonstrating efficacy of a pharmacologic intervention in reducing a biomarker strongly associated with breast cancer risk in lymphoma survivors with a past history of chest radiation. Disclosures Palomares: Covance: Other: Medical monitoring. Henderson:Seattle Genetics: Research Funding. OffLabel Disclosure: The drug is a low-dose tamoxifen, a selective estrogen receptor modulator. Tamoxifen in standard doses is used to reduce the risk of breast cancer in high risk populations. Tamoxifen in standard or low doses have not been tested before for chest-irradiated cancer survivors to reduce the risk of radiation-related breast cancer.

PURPOSE To update the ASCO guideline on pharmacologic interventions for breast cancer risk reduction and provide guidance on clinical issues that arise when deciding to use endocrine therapy for breast cancer risk reduction. METHODS An Expert Panel conducted targeted systematic literature reviews to identify new studies. RESULTS A randomized clinical trial that evaluated the use of anastrozole for reduction of estrogen receptor–positive breast cancers in postmenopausal women at increased risk of developing breast cancer provided the predominant basis for the update. UPDATED RECOMMENDATIONS In postmenopausal women at increased risk, the choice of endocrine therapy now includes anastrozole (1 mg/day) in addition to exemestane (25 mg/day), raloxifene (60 mg/day), or tamoxifen (20 mg/day). The decision regarding choice of endocrine therapy should take into consideration age, baseline comorbidities, and adverse effect profiles. Clinicians should not prescribe anastrozole, exemestane, or raloxifene for breast cancer risk reduction to premenopausal women. Tamoxifen 20 mg/day for 5 years is still considered standard of care for risk reduction in premenopausal women who are at least 35 years old and have completed childbearing. Data on low-dose tamoxifen as an alternative to the standard dose for both pre- and postmenopausal women with intraepithelial neoplasia are discussed in the Clinical Considerations section of this article. Additional information is available at www.asco.org/breast-cancer-guidelines .

TPS4162 Background: 4-10% of PDAC patients harbor pathogenic germline variants in cancer susceptibility genes, including APC, ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, and TP53. For families with such pathogenic variants, the greatest potential impact of germline testing is to identify relatives with the same pathogenic variant (cascade testing), thereby providing the opportunity for early detection and cancer interception of PDAC and other associated malignancies. Numerous factors limit cascade testing in real-world practice, including family dynamics, widespread geographic distribution of relatives, access to genetic services, and misconceptions about the importance of germline testing, such that the preventive benefits of cascade testing are often not fully realized. The primary aim of this study is to analyze two alternative strategies for cascade testing in families with inherited PDAC susceptibility. Methods: 1000 individuals (from approximately 200 families) with a confirmed pathogenic germline variant in any of the above genes in a 1st/2nd degree relative and a 1st/2nd degree relative with PDAC will be remotely enrolled through the study website (www.generatestudy.org) and randomized between two different methods of cascade testing (individuals with prior genetic testing will be ineligible): Arm 1 will undergo pre-test genetic education with a pre-recorded video and live interactive session with a genetic counselor via a web-based telemedicine platform (Doxy.me), followed by germline testing through Color Genomics; Arm 2 will undergo germline testing through Color Genomics without dedicated pre-test genetic education. Color Genomics will disclose results to study personnel and directly to participants in both arms. Participants in both arms will have the option of pursuing additional telephone-based genetic counseling through Color Genomics. The primary outcome will be uptake of cascade testing. Secondary outcomes will include participant self-reported genetic knowledge, cancer worry, distress, decisional preparedness, familial communication, and screening uptake, which will be measured via longitudinal surveys. Enrollment will begin February, 2019. Clinical trial information: NCT03762590.

1527 Background: Prospective Registry of Multiplex Testing (PROMPT) is an online registry for individuals who have had multiplex panel testing for cancer susceptibility. The main objective of this registry is to ascertain families to allow penetrance calculations for mutations in less well characterized genes. Methods: Since September 2014, health care providers and commercial laboratories have given PROMPT information with the test results to eligible individuals. Participants with pathogenic mutations or variants of unknown significance in cancer susceptibility genes have self-enrolled in PROMPT. We have sent annual follow-up surveys to participants to capture updated personal and family histories, additional genetic testing in the family, and changes in cancer screening patterns. Results: To date, 5800 participants have enrolled in PROMPT and 2321 follow-up surveys are completed. Of those eligible for follow-up, 1980 (44%) have completed at least one survey. 134 (5.8%) reported a new cancer diagnosis since baseline. Breast cancer (37, 27.6%) and non-Melanoma skin cancer (35, 26.2%) were the most commonly reported new diagnoses. 5.7% of participants with an ATM variant, 5.2% of those with a BRCA2 variant, and 4.3% of those with a CHEK2 variant and at least one follow-up survey have reported a new primary cancer diagnosis (excluding non-Melanoma skin cancer). In addition, 70 (3%) participants reported a cancer recurrence since time of last follow-up. Bone (9, 12.9%) and liver (8, 11.4%) were the most common recurrence sites. 12.7% of those with a TP53 variant, 7.1% of those with a BARD1 variant, and 3.3% of those with an ATM variant and at least one follow-up survey have reported a recurrence. 59 (2.5%) participants had additional clinical genetic testing, and 555 (24%) participants reported clinical genetic testing of family members. Conclusions: PROMPT collects updated health information from participants to achieve the primary goal of determining cancer incidence among carriers of different mutations. Moreover, PROMPT has increased participant contacts through use of annual follow-up surveys and gene-specific surveys with subsets of participants. Ongoing efforts include obtaining pathology reports of new and recurrent cancer diagnoses on study.