The management of hereditary breast and ovarian cancer (HBOC) in Japan has changed drastically with the expansion of indications for poly ADP-ribose polymerase inhibitors, the increase in diagnostic opportunities with the spread of companion diagnoses, and partial insurance coverage of HBOC management. These circumstances require a response that is coordinated across the entire hospital rather than from individual departments. In April 2021, we established the HBOC Center, which is operated by nine departments: Obstetrics and Gynecology, Reproduction, Surgery (breast group, hepato-pancreato-biliary group), Urology, Dermatology, Neuropsychiatry, the Center for Medical Genetics, and the Cancer Center. In addition to discussions of individual cases, our monthly conferences have enabled us to establish indication criteria and appropriate items for surveillance, visualize the examination flow in the hospital, construct a patient database, and provide open lectures to educate the public. The future HBOC management system should not only fulfill the existing requirements for risk-reducing surgery and facility standards but also offer comprehensive and diversified attention based on the needs of patients and their family members.

In Japan, the rising incidence of hereditary breast and ovarian cancer syndrome (HBOC) follows partial insurance coverage introduced in 2020. Compared with the general population (~11% lifetime risk), individuals with HBOC face a significantly higher lifetime risk of breast cancer (48%–76%), often presenting at younger ages. BRCA1 mutations are linked to triple-negative breast cancer, whereas BRCA2 mutations typically result in luminal-type disease. Key risk management strategies include surveillance and prophylactic surgery. Annual magnetic resonance imaging and mammography are recommended at younger ages than in the general population, despite concerns regarding contrast agents, radiation exposure, and examination-related burdens. Although risk-reducing mastectomy lowers breast cancer risk by over 90%, it remains underutilized because of cosmetic and psychological considerations. Nipple-sparing or skin-sparing mastectomy combined with immediate or delayed reconstruction offers a balance between risk reduction and postoperative outcomes, although safety and procedure details still warrant careful evaluation. Managing the high breast cancer risk associated with HBOC requires ongoing efforts to refine current strategies while minimizing patient burden.

High-grade serous carcinoma (HGSC), the most aggressive subtype of epithelial ovarian cancer, is strongly associated with hereditary breast and ovarian cancer (HBOC) syndrome and is primarily linked to germline BRCA1/2 pathogenic variants (PVs). The cumulative risks of ovarian cancer by the age of 70 years are 40% and 18% for carriers of BRCA1 and BRCA2 PVs, respectively. Risk-reducing salpingo-oophorectomy (RRSO) is a recommended preventive strategy that reduces the risk of ovarian cancer by more than 80% and may improve overall survival. However, surgical menopause after RRSO poses several challenges, including infertility and hormonal deficiency. Although the use of hormone replacement therapy may alleviate symptoms, it requires careful consideration of breast cancer risk. Emerging strategies, such as prophylactic salpingectomy with delayed oophorectomy, are being investigated to balance cancer prevention and patient quality of life. Further research is required to refine personalized prevention and management approaches for HBOC-associated ovarian cancer.

A program of recruiting families with hereditary pancreatic cancer and hereditary breast and ovarian cancer (HBOC) syndrome as high-risk individuals for pancreatic cancer surveillance using magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasound (EUS) has proven effective, resulting in the improvement of early detection rates and life expectancy. Given this, recent guidelines recommend pancreatic surveillance for patients with familial pancreatic cancer and pathological variants of ten genes, including BRCA1/2. In April 2021, our hospital established the HBOC Center, which is operated by nine departments, including obstetrics and gynecology, breast surgery, pancreatology, urology, medical genetics, dermatology, psychiatry and neurology, and oncology. Currently, MRCP or EUS is performed once or twice a year in 63 cases with pathogenic variants in 54 families. Although 4 cases (6.3%) revealed pancreatic microcysts or branched intraductal papillary mucinous neoplasms, no sign of pancreatic cancer was detected. Since January 2021, the germline BRCA1/2 test for companion diagnosis of pancreatic cancer has been covered by insurance, improving the accessibility of genetic testing among patients with pancreatic cancer. However, the BRCA1/2 positivity rate remains low at 1.3%, and its indication for use is very limited. The implementation of genetic testing, including BRCA1/2 analysis, is necessary for the prevention and early detection of pancreatic cancer in high-risk families.

Hereditary breast and ovarian cancer syndrome (HBOC) is a hereditary tumor syndrome caused by mutations in BRCA genes. Advances in genetic testing technologies have enabled surveillance and risk-reducing surgeries for carriers of BRCA mutations, allowing for the early detection and prevention of cancer. However, the research and support infrastructure for addressing the psychological and social impacts of genetic diagnostics remain insufficient, and there is a need for mental and psychological support based on the needs of patients and their families. Here, we provide an overview of mindfulness, a psychotherapy that has been demonstrated to be effective in alleviating psychological distress in cancer patients, and we discuss the prospects for mindfulness therapy in HBOC patients.

Hereditary breast and ovarian cancer syndrome (HBOC) is traditionally associated with mutations in the BRCA1 and BRCA2 genes, predominantly impacting breast, ovarian, pancreatic, and prostate cancers. However, recent research suggests that these mutations may also predispose carriers to a broader spectrum of malignancies, including biliary tract, cervical, colorectal, endometrial, esophageal, and gastric cancers. This review presents findings from extensive datasets, including a significant study from a nationwide Japanese biobank that examined cancer risks in 63,828 patients and 37,086 controls. Our review highlights notable associations, such as an increased risk of uterine and cervical cancers in BRCA1 mutation carriers and increased risk of esophageal and gastric cancers in BRCA2 mutation carriers. These emerging associations underscore the necessity of revisiting and potentially expanding current clinical guidelines to incorporate these additional risks. These findings advocate a comprehensive approach to genetic counseling and underscore the importance of tailored cancer surveillance strategies in populations carrying BRCA mutations. This expanded understanding could significantly influence preventive, diagnostic, and therapeutic strategies, promoting personalized approaches to manage and potentially prevent these malignancies in genetically susceptible populations.