Kurian, Allison W

Abstract We evaluated the joint associations between a new 313-variant PRS (PRS313) and questionnaire-based breast cancer risk factors for women of European ancestry, using 72 284 cases and 80 354 controls from the Breast Cancer Association Consortium. Interactions were evaluated using standard logistic regression and a newly developed case-only method for breast cancer risk overall and by estrogen receptor status. After accounting for multiple testing, we did not find evidence that per-standard deviation PRS313 odds ratio differed across strata defined by individual risk factors. Goodness-of-fit tests did not reject the assumption of a multiplicative model between PRS313 and each risk factor. Variation in projected absolute lifetime risk of breast cancer associated with classical risk factors was greater for women with higher genetic risk (PRS313 and family history) and, on average, 17.5% higher in the highest vs lowest deciles of genetic risk. These findings have implications for risk prevention for women at increased risk of breast cancer.

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.

6531 Background: This survey of Targeted Agent and Profiling Utilization Registry (TAPUR) Study physicians examined use, attitudes, and perception of tumor genomic testing (TGT), defined as any DNA test performed on tumor specimen/plasma. TAPUR is a multibasket study of marketed agents targeting tumor genomics. Methods: 333 physicians at 54 TAPUR sites were surveyed (2016-2017). Survey domains included use of TGT, barriers to ordering TGT, and genomic confidence. Surveys included 3 scenarios for TGT ordering 1) pretreated advanced cancer patients (pts) without options, 2) newly diagnosed, untreated, metastatic pts and 3) early stage/potentially curable pts with standard options. Data were analyzed with descriptive statistics. Results: 112 physicians responded (33%). The table displays demographics and genomic confidence. Respondents reported a median of 25% of their pts had TGT in past 12 months for trials/routine care (range 0-85%). Barriers to testing included access to tumor specimen (86%), insurance coverage (67%), concerns that results will not be actionable (55%), and test issues (wait time, unsure which test/lab to use, test accuracy) (54%). TGT was ordered most often for scenario 1 (96%) and 2 pts (70%). Few respondents (32%) would order testing in scenario 3. Of those who reported testing for scenarios 1 & 2, most told pts that results could inform treatment/prognosis/trials (97%) or may be uninformative (84%). In all scenarios, pt expectations of TGT results were discussed prior to testing. A minority reported frequently telling pts in advance that results could inform heritable cancer susceptibility (37%). Conclusions: Confidence in using TGT was high. TGT was performed most for pts with advanced cancer and few options. Availability of specimens was largest barrier reported, indicating the importance of blood-based tests. Few respondents discussed implications of germline findings in advance, despite growing evidence of germline findings in somatic testing. [Table: see text]