Orange County Gastrointestinal and Colorectal Cancer Doctors

Dr. Kasi is an associate clinical professor in the department of Medical Oncology & Therapeutics Research at City of Hope Orange County.

Ahmad Abou Abbass, M.D., F.A.C.S., is a nationally and internationally recognized hepatobiliary and pancreatic surgeon specializing in advanced minimally invasive and robotic techniques.

Amy Copeland, M.D., is a surgical oncologist treating gastrointestinal cancers such as stomach, small bowel, colon and appendix as well as soft tissue and retroperitoneal sarcomas.

Amir Esparza, M.D., F.A.C.S., is a colorectal surgeon double-board certified in general surgery and colorectal surgery and commitment to compassionate, high-quality care.

Mark Hanna, M.D., is an assistant clinical professor in the Division of Colorectal Surgery, Department of Surgery.

Specializing in bioengineering and tumor micro-environment in cancer development and progression, Andrew Nguyen, M.D., is an assistant clinical professor in the Division of Surgical Oncology in the Department of Surgery at City of Hope.

Mustafa Raoof, M.D., M.S., is a surgical oncologist and an assistant professor in the Department of Surgery and in the Department of Cancer Genetics and Epigenetics.

Yanghee Woo, M.D., is director of the Gastroenterology Minimally Invasive Therapy Program.

Omeed Alipour, M.D., is an interventional gastroenterologist with expertise in minimally invasive endoscopic techniques for the diagnosis and treatment of pancreatic and biliary diseases.

Lance Uradomo, M.D., M.P.H., is an assistant clinical professor, Division of Gastroenterology, Department of Medicine at City of Hope Orange County.

Luke Chen, M.D., is a medical oncologist and hematologist at City of Hope Orange County Lennar Foundation Cancer Center and Seacliff locations. Dr. Chen’s research has explored ways to improve treatment for prostate cancer and other malignancies.

Elizabeth Conner, M.D. is a gastrointestinal medical oncologist dedicated to advancing compassionate, research-driven cancer care.

Sudarsan Vishnu Kollimuttathuillam, M.D., is a medical oncologist and hematologist at City of Hope Orange County's Lennar Foundation Cancer Center and Seacliff locations. Dr. Kollimuttathuillan places a priority on offering his patients access to innovative treatments and clinical trial options.

Charisma Mylavarapu, D.O., is a dedicated physician specializing in gastrointestinal and genitourinary malignancies. Her journey into medicine was driven by a lifelong fascination with science and a deep commitment to community service.

Peter Ngo, M.D., is an assistant clinical professor, Department of Medical Oncology and Therapeutics Research at City of Hope Long Beach Elm and Worsham.

Krushangi Patel, M.D., is a highly engaged practitioner who prioritizes not only her patients' physical well-being but also their emotional and spiritual needs.

George Bernard Semeniuk, III, M.D., is a hematologist/oncologist specializing in leukemia, lymphoma and hematopoietic cell transplantation.

Tingting Tan, M.D., Ph.D., is a medical oncologist and assistant clinical professor in the Department of Medical Oncology & Therapeutics Research at City of Hope.

Percy Lee, M.D., is the medical director of Orange County and coastal region radiation oncology and vice chair for clinical research in the Department of Radiation Oncology.

Dr. Weng is a radiation oncologist and assistant clinical professor in the Department of Radiation Therapy at City of Hope Orange County.

Jason Salsamendi, M.D., is a interventional radiologist and clinical professor in the Department of Diagnostic Radiology at City of Hope.

Richard T. Lee, M.D., is the medical director of the Integrative Medicine Program in the Department of Supportive Care Medicine at City of Hope.

Jessica Cheng, M.D., is among the nation’s few, and Orange County’s only, fellowship-trained experts in cancer rehabilitation medicine. This is a subspecialty of physical medicine and rehabilitation (PM&R) also known as physiatry.