This book is a curated collection of research and perspectives on Hereditary Breast and Ovarian Cancer (HBOC). Due to the shared genetic basis of these conditions—particularly mutations in the BRCA1 and BRCA2 genes—this volume also explores advancements in reproductive medicine, perinatal medicine, pancreatic cancer, prostate cancer, and more. In addition to its focus on clinical practice, the book provides updated data from nationwide registration, including the frequency of rare BRCA1/2 variants and the current status of risk-reducing surgeries. As the field rapidly evolves with the clinical development of poly (ADP-ribose) polymerase (PARP) inhibitors and the integration of BRCA1/2 genetic testing into public health insurance systems, this volume offers a comprehensive overview of the latest developments and ongoing challenges in HBOC-related care.

Readers will explore key topics such as the molecular mechanisms of carcinogenesis due to BRCA1/2 mutations, the challenges of risk-reducing mastectomy decision-making, and the future of BRCA testing in breast cancer diagnosis. Contributions from leading experts provide a comprehensive overview of healthcare for HBOPPC patients, including reproductive medicine and perinatal care, while addressing critical questions about individualized risk management and genetic counseling.

This book is an essential resource for breast surgeons and oncologists, obstetricians, gynecologists, pancreatic cancer surgeons, urologists, and genetic medicine physicians. It also serves as a valuable reference for HBOC patients, their families, and pharmaceutical professionals involved in PARP inhibitor development. By sharing the latest research and clinical practices, this volume aims to equalize and enhance HBOPPC treatment across Japan.

Dr. Takanori Ishida is the Chairman of Japanese Breast Cancer Society. He graduated from the School of Medicine at Tohoku University in 1987. Following postgraduate training at Iwate Central Hospital, he specialized in breast surgical oncology and subsequently joined Tohoku University. He received his Ph.D. in Medical Science from Tohoku University in 1998.Throughout his academic career, he has held a number of positions at Tohoku University, including Assistant Professor, Lecturer, and Associate Professor. Since 2017, he has served as Professor and Chair of the Department of Breast and Endocrine Surgical Oncology at the Tohoku University Graduate School of Medicine.He retired from Tohoku University in 2025 and currently serves as the hospital president of Tohoku Kosei Hospital. His research interests encompass breast surgery, medical oncology, breast cancer screening, pathology, and hereditary breast and ovarian cancer (HBOC).

Dr. Natsuko Chiba received her M.D. from the Tohoku University School of Medicine in 1993 and earned her Ph.D. from the Tohoku University Graduate School of Medicine in 1997. She began her academic career as a Lecturer at the Institute of Development, Aging and Cancer, Tohoku University, followed by clinical training as a staff physician in internal medicine at Ishinomaki Red Cross Hospital. From 1999 to 2002, she conducted research as a Research Fellow in the Department of Pathology at Brigham and Women’s Hospital and Harvard Medical School. She subsequently served as a clinical oncologist at Tohoku University Hospital.Since 2003, Dr. Chiba has held several academic positions at the Institute of Development, Aging and Cancer, Tohoku University, including Assistant Professor, Associate Professor, and, since 2014, Professor in the Department of Cancer Biology. Her research focuses on hereditary breast and ovarian cancer (HBOC), cell cycle regulation, and DNA damage responses.

Dr. Hiroyuki Nomura received his M.D. from Keio University School of Medicine in 1998 and earned his Ph.D. in Medical Science from the same institution in 2007. He completed his residency training in obstetrics and gynecology at Keio University Hospital and subsequently conducted research at Keio University School of Medicine focusing on the molecular mechanisms of peritoneal dissemination in ovarian cancer, as well as interventional clinical trials in gynecologic cancers.He began his academic career as an Assistant Professor at Keio University School of Medicine in 2006. In 2019, he was appointed Associate Professor at Fujita Health University School of Medicine. Since 2024, he has been serving as Professor and Chair of the Department of Obstetrics and Gynecology at Tokai University School of Medicine.His clinical and research interests include gynecologic oncology, hereditary tumors, cancer drug therapy, clinical trials, and biomarker research. He is also an active member of the Japanese Organization of Hereditary Breast and Ovarian Cancer (JOHBOC).