It is with deep sadness that we share the passing of Dr. Masahiro Tsuboi, MD, PhD, a highly respected thoracic surgeon, researcher, and long-standing member of the International Association for the Study of Lung Cancer (IASLC).
Dr. Tsuboi’s sudden departure has sent ripples of grief through the global lung cancer community, leaving colleagues, mentees, and patients worldwide mourning a true pioneer. His life’s work fundamentally transformed surgical standards for early-stage disease and propelled targeted therapies like adjuvant osimertinib into routine practice, saving countless lives.
Professional Career
Dr. Masahiro Tsuboi’s career was a testament to his unwavering commitment to thoracic oncology. He held key leadership positions that fundamentally altered how Japan and the global community approached lung cancer surgery.
He advanced through the ranks at the National Cancer Center Hospital East (NCCHE) in Kashiwa, Japan. His tenure reached its zenith when he became Chief and Director of the Division of Thoracic Surgery and Oncology. He led multidisciplinary teams, advocating for less invasive techniques and providing meticulous care to thousands of individuals. He was a Visiting Professor at Yokohama City University Graduate School of Medicine. There, he guided the next wave of surgeons and contributed to academic research focused on tumor biology and surgical advancements.
His impact on a national scale was significant. He led the Japan Clinical Oncology Group (JCOG), and as Past Chair of the Lung Cancer Surgical Study Group, he directed collaborative trials. These trials established new standards for perioperative management in early-stage non-small cell lung cancer.
Dr. Tsuboi’s Landmark Trials
Dr. Masahiro Tsuboi’s research fundamentally altered the landscape of thoracic oncology, as his meticulous clinical trials integrated surgical techniques with molecular therapies, thereby shaping international benchmarks.
“Dr. Tsuboi will be remembered for his remarkable scientific contributions, his commitment to patients, and his generosity as a colleague and mentor.” International Association for the Study of Lung Cancer
Dr. Tsuboi’s contributions to the ADAURA trial were particularly significant; this study revealed that adjuvant osimertinib diminished the likelihood of disease recurrence or mortality by 80% (HR 0.20) in individuals with resected EGFR-mutant non-small cell lung cancer (NSCLC) across stages IB-IIIA. Furthermore, the NeoADAURA study expanded upon these results within neoadjuvant contexts, thereby reinforcing osimertinib’s significance in perioperative management.
These results directly shaped NCCN and ESMO guidelines, making targeted therapy a new standard for resectable EGFR-positive NSCLC.
JCOG0802 and JCOG0804
As a key leader, he drove JCOG0802, a trial of over 1,100 patients that initially (at 5 years) suggested segmentectomy’s non-inferiority to lobectomy in early-stage NSCLC but later 10-year data favored lobectomy for overall survival while affirming segmentectomy’s role in preserving function. JCOG0804 optimized perioperative strategies for stage IA disease, emphasizing intentional sublobar resection. Both trials informed NCCN recommendations for minimally invasive surgery in low-risk patients.
JIPANG
Dr. Tsuboi co-led the JIPANG trial, establishing pemetrexed plus cisplatin as superior adjuvant chemotherapy for nonsquamous NSCLC (stage II-IIIA), with improved recurrence-free survival over vinorelbine plus cisplatin—especially in EGFR wild-type subgroups. Its 5-year OS data reinforced ESMO endorsements for histology-driven adjuvant chemotherapy, enhancing outcomes in resected disease.
A Tribute Shared by the International Association for the Study of Lung Cancer (IASLC)
Dear IASLC Community,
It is with deep sadness that we share the passing of Dr. Masahiro Tsuboi, MD, PhD, a highly respected thoracic surgeon, researcher, and long-standing member of the International Association for the Study of Lung Cancer (IASLC). Dr. Tsuboi dedicated his career to advancing lung cancer research, improving surgical care, and supporting the global thoracic oncology community.
Dr. Tsuboi served as Chief and Director of the Division of Thoracic Surgery and Oncology at the National Cancer Center Hospital East in Kashiwa, Japan, and as a visiting professor at Yokohama City University Graduate School of Medicine. He played an important role in several global clinical trials, including the ADAURA and NeoADAURA studies, which helped advance targeted therapies for patients with EGFR-mutant non–small cell lung cancer.
He was also deeply involved in the Japan Clinical Oncology Group (JCOG) and served as Past Chair of the Lung Cancer Surgical Study Group. His leadership contributed to landmark surgical trials, including JCOG0802, JCOG0804, and the JIPANG trial, which helped shape modern treatment strategies for early-stage lung cancer.
Within IASLC, Dr. Tsuboi was a valued and active member of the community, serving on the IASLC Board of Directors, the Lung Cancer Staging and Prognostic Factors Committee, and the Education Committee, and as a faculty speaker at numerous IASLC conferences.
Through these roles, he helped advance global collaboration, contributed to the development of the TNM lung cancer staging classification, and supported education and research across the field of thoracic oncology.
Dr. Tsuboi will be remembered for his remarkable scientific contributions, his commitment to patients, and his generosity as a colleague and mentor. His legacy will continue to influence the field of lung cancer research and care for years to come.
We extend our deepest condolences to his family, friends, colleagues, and the many people whose lives were touched by his work.
Sincerely,
President IASLC – Caicun Zhou MD
Cheif Executive Officer, IASLC – Karen Kelly MD
Dr. Tsuboi’s Global Influence
Dr. Masahiro Tsuboi’s global influence extended far beyond Japan, forging bridges between Eastern surgical traditions and Western molecular oncology through prolific scholarship and international collaboration. He was a sought-after faculty speaker at premier conferences, delivering keynote lectures on perioperative strategies at ESMO Congress, ASCO Annual Meetings, and AATS gatherings, where he shared insights from his trials with thousands of oncologists worldwide.
Key collaborations included partnerships with Western investigators on NeoADAURA alongside AstraZeneca, integrating osimertinib into global perioperative protocols, and his role in multinational staging efforts that refined TNM classifications for lung cancer.
With over 200 peer-reviewed publications and an h-index near 50, Dr. Tsuboi bridged Eastern precision in minimally invasive surgery with Western advances in targeted therapies, elevating outcomes for EGFR-mutant NSCLC patients everywhere.
Written by Aharon Tsaturyan, MD, Editor at OncoDaily Intelligence Unit