This application is submitted by Brigham and Women's Hospital (BWH), a Harvard- affiliated teaching hospital located in Boston, and requests funding to continue a training program for cancer surgeons, the Advanced Training in Surgical Oncology (ATSO) program. ATSO supports laboratory-based cancer research for surgical residents who wish to pursue a career in general surgical or thoracic oncology. The program is primarily directed toward residents from BWH, but also includes other Harvard-affiliated residencies and postgraduate programs throughout the United States. ATSO leaders also make a deliberate attempt to recruit applicants from underrepresented minorities. The overall goal of ATSO is to dramatically improve care of cancer patients by training surgeon-scientists who will devote their careers to studying and implementing biologically-based cancer treatment. This goal is particularly important now, as surgeons are at the forefront of the revolution in personalized medicine. The ATSO program achieves this aim by exposing surgical residents to the best discovery and translational research available in the Harvard system, placing them in laboratories led by mentors who are accomplished scientists and educators. ATSO includes formal didactic sessions to familiarize trainees with the fundamentals of basic, translational and clinical research, including programs in research ethics. Through the work of its Governance Board, ATSO provides frequent career development and progress review interactions with trainees and the ATSO itself is continually enriched through formal evaluations by its Advisory Board and the trainees themselves. Our well-established program has a solid record of success, with 91% of post-ATSO trainees from the last 10 years successfully pursuing a career in academic medicine. We look forward to improving this record even further by meeting the challenges of an ever-increasing societal need for talented, well-trained and well-supported surgeon-scientists.