Merrill, Margaret S.

e13680 Background: Multiplex genetic testing (MGT) simultaneously analyzes multiple cancer susceptibility genes and can reveal genetic variants of uncertain significance (VUS) that have unclear associations with cancer risks. Little is known about how people are prepared for receiving VUS results from MGT, or whether their emotional reactions differ based on the levels of cancer risk to which they may be susceptible. Methods: We recruited participants from the online Prospective Registry of Multiplex Testing (PROMPT). Those with only a VUS in a cancer predisposition gene completed a survey including measures of their MGT experience, distress (range 0-30; α = .87), uncertainty (0-45; α = .83), and positive experiences (0-20; α = .75). We used generalized linear modeling to examine how demographics, awareness of the possibility of VUS before testing, and level of cancer risks associated with their VUS gene were related to emotional outcomes. Results: Data were available from 661 individuals (40% response rate, 95% female, 90% white, 78% college graduate, 69% cancer history, age 23-93) with VUS in a gene of high risk (47%), moderate/low risk (35%) or limited evidence of risk (18%). Among the sample, 80.8% reported ever receiving cancer genetic counseling, and only 50.8% reported being aware of the possibility of VUS when deciding about testing. Participants reported low current distress ( M± SD= 3.25±5.19), uncertainty (9.18±8.35) and positive experiences (7.83±5.98). Distress was associated with younger age, less family cancer history, and being unaware of the possibility of VUS before testing; distress was also higher among those with VUS in a gene of high risk than those with VUS in a gene of moderate/low risk or limited evidence of risk ( ps≤.023). Uncertainty was associated with younger age, non-white race, less education, and being unaware of the possibility of VUS; uncertainty was also higher among those with VUS in a gene of high risk than those with VUS in a gene with limited evidence of risk ( ps≤.05). Fewer positive experiences were associated with more education and more family cancer history; those with VUS in a gene of high risk had fewer positive experiences than those with VUS in a gene with limited evidence of risk ( ps≤.03). Conclusions: Many individuals undergoing MGT may not fully understand the prospect of receiving VUS. Clinicians should consider patients’ background, preparation, and level of cancer risk to which they are potentially susceptible, as these factors may affect their emotional adaptation.

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.