A Japanese case of familial malignant melanoma with germline CDK4 variant incidentally diagnosed by cancer genome profiling.

Familial malignant melanoma (FMM) is a hereditary tumor that is quite rare in Japan; to date, the germline CDK4 variant has scarcely been reported around the world. Thus, we report on a woman with FMM who developed salivary gland cancer, for which a germline pathogenic variant of CDK4 was incidentally identified through comprehensive genomic profiling. She had a history of multiple atypical nevi and a facial melanoma since her 30 s and multiple family histories of melanoma; however, none of her relatives were aware of its heredity. Genetic counseling and skin surveillance were performed. Precision medicine for cancer can discover this rare genetic syndrome and provides us with the opportunity to manage the health of patients and their relatives.

Present status of germline findings in precision medicine for Japanese cancer patients: issues in the current system.

OBJECTIVE: Since 2019, precision cancer medicine has been covered by national insurance in Japan; however, to date, germline findings have not been fully reported. The aim of this study was to evaluate the current status and raise a problem of germline finding analysis and disclosure in Japanese precision cancer medicine. METHODS: Germline findings of 52 genes were examined in 296 cases with advanced cancer by a case series study. RESULTS: Six (2.0%) cases were examined by the Oncoguide™ NCC Oncopanel with germline testing, but no germline findings were reported. The remaining 290 (98.0%) cases were analyzed by FoundationOne® CDx (tumor-only testing), which recognized 404 pathogenic variants; those of BRCA1/2 were recognized in 16 (5.5%) tumors. Our institutional algorithm suggested 39 candidate germline findings in 34 cases, while the public algorithm listed at least 91 candidate germline findings. Four germline findings had been previously identified (BRCA1: 3 and ATM: 1). Nine of 30 cases with candidate germline findings excluding these known germline findings refused or deferred germline testing. Only 4 of 16 cases that received counseling underwent germline testing, and those 4 revealed 3 germline findings (BRCA2, CDK4 and RAD51C); in total, 8 (2.7%) germline findings were revealed. Reasons for refusing genetic counseling and/or germline testing included extra hospital visits, added expense for germline testing due to limited national insurance coverage, poor patient physical condition and no known family members associated with the possible germline finding. CONCLUSIONS: In current Japanese precision cancer medicine, only a small fraction of the patients undergoes germline testing and demonstrated germline finding. The current results suggested a need for earlier indications for precision cancer medicine, broader insurance coverage and more efficient germline finding prediction algorithms, to increase the number of germline testings and to improve the following managements.

Sharing genetic test results of germline pathogenic variants of hereditary cancer with relatives: A single-center cross-sectional study.

OBJECTIVE: This study aimed to determine whether Japanese cancer patients share test results of germline pathogenic variants of hereditary cancer with their relatives. METHODS: This single-center cross-sectional study enrolled 21 Japanese patients who received results of germline pathogenic variants of hereditary cancer at least 6 months prior. RESULTS: All patients shared their test results with at least one relative, with the following sharing rates: 85.7% for first-degree relatives, 10% for second-degree relatives and 8.3% for third-degree relatives. Patients most commonly shared the information with their children aged >18 years (86.7%), followed by their siblings (73.6%), spouses (64.7%) and parents (54.5%). Three categories were extracted from qualitative analysis: 'characteristics of my cancer', 'knowledge and caution about inheritability' and 'utilization of medical care.' CONCLUSIONS: The rate of test result sharing with first-degree relatives was comparable with those in Europe and the USA. Patients with germline pathogenic variants also tended to share their test results more with their children and siblings than with their parents. Informing their relatives of the results was suggestive of the motivation to influence their relatives' health outcome and contribute to the well-being of their children and siblings.

A Cross-sectional Study of Regret in Cancer Patients After Sharing Test Results for Pathogenic Germline Variants of Hereditary Cancers With Relatives.

BACKGROUND: Research on whole genome/exome sequencing is increasing worldwide. However, challenges are emerging in relation to receiving germline pathogenic variant results and sharing them with relatives. OBJECTIVE: The aim of this study was to investigate the occurrence of and reasoning related to regret among patients with cancer who shared single-gene testing results and whole exome sequencing with family members. METHODS: This was a single-center, cross-sectional study. The Decision Regret Scale was administered, and descriptive questionnaires were used with 21 patients with cancer. RESULTS: Eight patients were classified as having no regret, 9 patients were classified as having mild regret, and 4 patients were classified as having moderate to strong regret. Reasons patients felt that sharing was the right decision included the following: to allow relatives and children to take preventive measures, the need for both parties to be aware of and ready for the hereditary transmission of cancer, and the need to be able to discuss the situation with others. On the other hand, some patients did not think it was a good decision to share the information because of the associated anxiety. CONCLUSIONS: Regret over sharing test results for pathogenic germline variants of hereditary cancers with relatives tended to be low. The main reason was that patients believed that they were able to benefit others by sharing. IMPLICATIONS FOR PRACTICE: Healthcare professionals need to understand the postsharing perceptions and experiences of patients and support them throughout the sharing process.