Abstract P2-05-02: Potential Empowerment and risk of Genetic Counseling with Genetic Breast cancer risk assessment in Personalized Health Care: Prospective Cohort Study using Genetic Counseling Outcome Scale (GCOS-24)

Abstract [Introduction] Personalized health care is recommended for the prevention and early detection of breast cancer. Advances in technology have made it possible to estimate genetic risk, PGV (pathogenic/likely-pathogenic germline variant) or PRS (polygenic risk score), in practice. However, linkage after risk assessment to personalized health care is still developing. One of the issues is how to tell the result especially in case of newly diagnosed PGV after Genetic Panel Testing or PRS. In this study, we evaluated genetic counseling (GC) using an established patient-reported outcome measure for clinical genetics services scale (Genetic Counseling Outcome Scale24 (GCOS24)) at genetic counseling for disclosure the results of the previous study, and examined the association with management after GC. [Method] We performed targeted sequencing for 11 breast cancer-related genes using peripheral blood DNA from 1995 female breast cancer patients. Of 1995 cases, 101 patients were PGV carriers, who were candidates of this study. Participants were referred to the Clinical Genetics unit, Kyoto University Hospital from 10 institutions (January 2018-March 2022). GCOS24 and relating questionaries were asked before and after GC. GCOS24 is a scale consisting of 24 items that assess five factors: decision control, cognitive control, behavioral control, emotional regulation, and hope. (In light of the current status of hereditary breast cancer care in Japan, 23 items were used.) Each item is rated on a scale of 1-7 points, for a total score of 23-161. In addition, we reviewed medical records to evaluate the post-GC management. [Results] Of the 101 cases, 38 cases were enrolled. The reasons of 63 not-enrolled cases were: 30 cases without follow-up (deaths or transfer to another hospital), 11 cases already diagnosed in clinical practice, 18 cases that did not wish to know their results, and 4 cases whose hospital were developing for hereditary breast cancer care. Median age at the time of genetic GC was 55 (min-max 30-83) years. Details of PGV cases were: BRCA2 23 cases, BRCA1 2, PALB2 4, PTEN 3, TP53 3, ATM 1, CHEK2 1 and NF1 1. GCOS24 after GC were improved than before GC. (Average 99 (min-max 17-124) vs 114 (91-138), Mean difference 23.9, 95% Confidence intervals (CI) 29.6 to 18.3). Thirty patients (79%) had higher increase in scores than 10.3, which was the previously reported Minimum Clinically Important Difference (MCID) of this scale. In all items except 4 items (#6,11,13,21), GCOS24 after GC were significantly improved than before GC. In post-GC management, 8 patients received or planned RRSO (risk reducing salpingo-oophorectomy) among 25 BRCA1/2 cases. There was a case with dysplastic cells detected in the resected ovary. After GC, average of GCOS24 in RRSO cases was 120 (95% CI 110 to 129), while average of GCOS24 of other BRCA1/2 cases was 110 (95% CI 104 to 116). On the other hand, two patients stopped visiting to the hospital because of fear after GC. Average of GCOS24 of 15 junior-high/high school graduate cases were 111 (95% CI 105 to 117), while average of GCOS24 of 23 college graduate cases were 117 (95% CI 111 to 122). [Discussion] In patients diagnosed with hereditary breast cancer by genetic panel testing, GC worked well except for 4 items. These 4 items (#6,11,13,21) were related to emotion. This study revealed there was also a risk to reject surveillance due to fear, suggesting that it is necessary to provide psychological support in some cases. Although the limitation of this study is the small number of cases, GCOS24 were high in RRSO cases, suggesting that GC played an important role when proceeding with intervention. We believe that the findings are helpful for the future implementation of genetic panel testing or PRS testing in healthy subjects for personalized health care. Citation Format: Nobuko Kawaguchi-Sakita, Noriko Senda, Yukiko Inagaki-Kawata, Hiromi Murakami, Sayaka Honda, Takahiro Yamada, Yuki Kataoka, Shoko Takahara, Shigeru Tsuyuki, Kazuhiko Yamagami, Yoshio Moriguchi, Masae Torii, Tatsushi Kato, Hirofumi Suwa, Wakako Tsuji, Eiji Suzuki, Akira Yamauchi, Ryuji Okamura, Shinji Kosugi, Masakazu Toi. Potential Empowerment and risk of Genetic Counseling with Genetic Breast cancer risk assessment in Personalized Health Care: Prospective Cohort Study using Genetic Counseling Outcome Scale (GCOS-24) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-05-02.