OCOH Treatment Center has been providing superior treatment to our patients since 2002. The facility is

Our staff is experienced and friendly. We are here to help our patients feel comfortable during treatment.

Welcome to Our Practice

Greg Richard Angstreich, M.D.

Dr. Greg Angstreich

Dr. Greg R. Angstreich joined OCOH in July 2011 from New Haven, Connecticut, where he was in practice since 2004. While there, he was a partner with Medical Oncology and Hematology, P.C., as well as a member of the medical staff at Yale-New Haven Hospital.

Prior to that, Dr. Angstreich completed a Medical Oncology and Hematology Fellowship at the Johns Hopkins Hospital Sidney Kimmel Comprehensive Cancer Center in Baltimore, Maryland, from 2001-2004.

His formal medical training began with the Traditional Internal Medicine Internship and Residency Program at Barnes-Jewish Hospital in St. Louis, Missouri, from 1997-2000.

Additionally, he graduated with College Honors from Washington University in 1993 and with a Letter of Commendation from Washington University School of Medicine in 1997, both in St. Louis, Missouri.

Dr. Angstreich is a member of the American Society of Clinical Oncology and the American Society of Hematology. He is also Board Certified in Internal Medicine, Hematology and Medical Oncology and has vast experience treating all malignancies, as well as all benign and cancerous blood disorders.

Originally from New York, Dr. A has been visiting friends and family in Southern California for years and is now quite pleased to be living in Newport Beach. He enjoys snow skiing, playing chess, reading and spending time with his 2 daughters, Madeline and Emily. He also is planning to learn how to surf!

Minh D. Nguyen, M.D.

Dr. Minh Nguyen

Dr. Nguyen joined our practice in July 2007 and has been in the study of medicine for over a decade. His impressive knowledge and experience is colored by his travels across the United States treating a variety of people around the country.

He began his medical journey in 1997, completing his Bachelor of Science Degree at the University of Michigan in 1997. Traveling to Detroit, MI he went on to receive his Medical Degree from Wayne State University School of Medicine in 2002. After spending his internship and residency at William Beaumont Hospital in Royal Oak, MI from 2002-2005. Minh Nguyen completed his fellowship in Medical Oncology at William Beaumont Hospital in 2007. During his studies he garnered multiple distinguished awards and accomplishments during his educational career which pointed to his promising future.

With Dr. Nguyen’s desire to expand his knowledge, in an effort to serve his patients more fully, he continued to affiliate himself with a variety of Medical boards and associations including Board Certification in Internal Medicine and board certification in medical oncology. He is a member of several professional societies, including the American Society of Clinical Oncology.

A native of Michigan, Dr. Nguyen resides in Irvine, CA with his wife and 3 children.  When he’s not caring for his patients, Dr. Nguyen focuses his time and energy on his family.  He also enjoys basketball, golf, and an occasional home improvement project. 

George B. Semeniuk III, M.D.

Dr. George Semeniuk

Dr. Semeniuk joined OCOH in 2002 after completing his Fellowship in Hematology and Oncology at Parkland Hospital, University of Texas Southwestern Medical School, Dallas, TX, from 1999-2002. He was Chief Medical Resident at Alameda County Medical Center, University of California at San Francisco, Oakland, CA, 1998-1999 following a residency there in 1996-1998. He also did his Internship at Alameda County Medical Center, University of California at San Francisco, Oakland, CA, 1995-1996, He received his M.D. from St. George’s University School of Medicine, Bay Shore, NY, in 1995. Dr. Semeniuk is Board Certified in Medical Oncology. He has several awards and honors and is an active member of many professional societies including the American Society of Clinical Oncology and the American Society of Hematology.

Dr. Semeniuk has specialized expertise in blood and coagulation disorders, including gastrointestinal malignancies and Integrative Oncology. He has completed an Associate Fellowship in Integrative Medicine at the University of Arizona in Tucson, Arizona with Dr. Andrew Weil.

Dr. Semeniuk incorporates a holistic philosophy to the treatment of cancer, incorporating diet, exercise and nutritional supplements to promote the body’s natural ability to heal itself while undergoing conventional chemotherapy and radiation. He supports many of his patients who choose to integrate complimentary and alternative modalities to their cancer treatments.

Dr. Semeniuk currently resides in Newport Beach and has successfully competed as an amateur boxer. He enjoys golf, surfing, scuba diving and opera to relax.

Louis A. VanderMolen, M.D.

Dr. Vandermolen

Dr. VanderMolen received his medical training at Loyola University Stritch School of Medicine, Maywood, Illinois, graduating as a Doctor of Medicine in 1980. He did an Internship in Internal Medicine in 1980-81 and Residency in 1981-83 at Baylor College of Medicine, Affiliated Hospitals, Texas Medical Center in Houston. He was Chief Medical Resident at The Methodist Hospital, Houston, Texas, in 1983.
Dr. VanderMolen has a fellowship in Hematology from Baylor College of Medicine, Affiliated Hospitals, Texas Medical Center College (1984) and another Fellowship in Oncology from the National Cancer Institute, Medical Branch, Clinical Oncology Program, Division of Cancer Treatment (1987-1989).

He was with the U.S. Public Health Service (1984-1987) and is Board Certified: American Board of Internal Medicine (1983) and American Board of Internal Medicine, Oncology Subspecialty (1989)

Prior to establishing his practice in May 1991, Dr. VanderMolen worked in private practice in Memphis, Tennessee, and Newport Beach, California. He is a member of several societies and has had several university, hospital, and other appointments.
Dr. VanderMolen resides in Laguna Beach with his daughter, Caitlin.  His interests include skiing, golf and piloting airplanes.


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