Prof. Tanaka Masahiro

Prof. Tanaka Masahiro is a Professor of Medical Oncology at the University of Tokyo Hospital, one of Japan's most prestigious academic medical institutions. With over 26 years dedicated to cancer medicine, he is internationally recognized for his work in gastrointestinal oncology, particularly in the treatment of gastric cancer — a disease with disproportionately high incidence in Japan.

After earning his MD and PhD from the University of Tokyo, Prof. Tanaka completed training in internal medicine and oncology at the University of Tokyo Hospital before pursuing postdoctoral research at the National Cancer Institute (NCI) in Bethesda, Maryland, USA. His research there focused on targeted therapies and early-phase clinical trials in gastrointestinal malignancies.

Returning to Japan, he established and now leads the gastrointestinal oncology program at the University of Tokyo Hospital. He is the principal investigator on multiple clinical trials investigating novel immunotherapy combinations and biomarker-directed therapies in gastric and colorectal cancer.

Prof. Tanaka is a prominent figure in the translation of Japan's cancer research into clinical practice, having contributed to national cancer treatment guidelines. His approach to oncologic care emphasizes molecular tumour profiling, multidisciplinary team decision-making, and integrating clinical trial access as standard-of-care for eligible patients.

Prof. Tanaka earned his MD and PhD from the University of Tokyo Faculty of Medicine. He completed his internal medicine residency and oncology fellowship at the University of Tokyo Hospital before undertaking a postdoctoral research fellowship at the National Cancer Institute (NCI), National Institutes of Health, Bethesda, USA.

He holds board certifications in Internal Medicine and Medical Oncology from the Japanese Society of Internal Medicine and the Japanese Society of Medical Oncology respectively. Prof. Tanaka has been a visiting professor at Memorial Sloan Kettering Cancer Center, New York, and the European Institute of Oncology, Milan.

Prof. Tanaka's clinical expertise is centered on the systemic treatment of solid tumours, with particular focus on gastrointestinal cancers. He designs and manages complex chemotherapy regimens and has deep experience with HER2-targeted therapy in gastric cancer, VEGF-targeted agents in colorectal cancer, and immune checkpoint inhibitors across multiple tumour types.

He co-leads the University of Tokyo Hospital's molecular tumour board, which reviews complex cancer cases to identify actionable genetic alterations and match patients with appropriate targeted therapies or clinical trials. He coordinates care with surgical oncology, radiation oncology, and palliative care teams.

Prof. Tanaka is also experienced in managing cancer-related complications including chemotherapy toxicity, paraneoplastic syndromes, and cancer pain, and works closely with palliative care specialists for patients with advanced disease.

Prof. Tanaka has authored over 150 peer-reviewed publications in journals including the New England Journal of Medicine, The Lancet Oncology, and the Journal of Clinical Oncology. His pivotal trial contributions have helped establish immunotherapy combinations as standard treatment for advanced gastric cancer internationally.

He has been principal investigator on phase I, II, and III trials for novel agents in gastrointestinal oncology sponsored by international pharmaceutical companies and the Japan Agency for Medical Research and Development (AMED). Prof. Tanaka is a member of the steering committees of several global oncology cooperative groups and has presented at ASCO Annual Meeting, ESMO Congress, and the Japanese Cancer Association.

Prof. Tanaka consults international patients at the University of Tokyo Hospital, which has a dedicated international patient liaison service. He consults in Japanese and English, and the hospital provides certified medical interpreters for other languages.

International patients — particularly those seeking access to Japan's world-class oncology clinical trials or seeking second opinions from a leading authority on gastric or colorectal cancer — are encouraged to contact the hospital's international patient centre to arrange a consultation. Japan is recognized as a global leader in early-phase cancer trials and precision oncology.

Video consultations are available for second opinions, where Prof. Tanaka can review pathology, imaging, and molecular profiling reports and provide a detailed assessment of treatment options.

Prof. Tanaka has received the Japanese Cancer Association's Award for Outstanding Research Contributions and the Japanese Society of Medical Oncology's Excellence in Clinical Research Award. He has been named among Japan's leading oncologists in independent medical research rankings.

He holds honorary fellowships from the Royal College of Physicians of Edinburgh and the European Society for Medical Oncology (ESMO). Prof. Tanaka serves on the editorial boards of the Journal of Gastroenterology and Gastric Cancer.