breast cancer program

Breast Cancer Physicians


Our dedicated, compassionate and experienced team of board-certified physicians from many specialties, including radiology, surgical oncology, pathology, medical oncology and radiation oncology, provide comprehensive care tailored to meet the unique needs of each patient. Each physician's experience and commitment will help support and guide you in your breast cancer care and journey.

Meet Our Physicians


Peter Ashjian, MD

Plastic Surgery/Breast Reconstruction

Dr. Ashjian is a board-certified plastic surgeon specializing in cosmetic and reconstructive surgery, particularly breast reconstruction. Over the past decade, he has performed hundreds of these operations, employing innovative techniques to enhance the lives of his patients. He is a member of the American Society of Plastic Surgeons, American Society of Reconstructive Microsurgery and Armenian American Medical Society of California. Dr. Ashjian studied medicine at the New York University School of Medicine where he graduated as a member of the Alpha Omega Alpha Honor Medical Society.


Boris Bagdasarian, DO

Medical Oncology

Dr. Bagdasarian practices hematology and oncology and has 21 years of experience in the medical field. He completed his residency in internal medicine at Adventist Health White Memorial and continued to specialize in hematology as a chief fellow in oncology and bone marrow transplantation at the renowned City of Hope National Medical Center and UCLA. Dr. Bagdasarian studied at Western University of Health Sciences, where he graduated magna cum laude. He is actively involved in cancer research and has been the principal investigator and co-investigator of numerous publications.


Sam Carvajal, MD

General Surgery

Dr. Carvajal has more than 25 years of experience in general surgery and vascular surgery and specializes in minimally invasive surgery. He graduated from the University of California, San Francisco School of Medicine, where he also completed an additional seven years of training in advanced surgical techniques. Board certified in general surgery, Dr. Carvajal has performed many breast surgeries, including lumpectomy and mastectomy, throughout his career. He is the physician liaison for the American College of Surgeons and provides state-of-the-art care for breast diseases.


Linh Chen, MD


Dr. Chen provides gentle care and expertise in women's imaging to her patients. As the medical director of the Women’s Imaging Department, she provides years of experience in mammography, breast and body ultrasound and breast biopsies. Dr. Chen graduated summa cum laude in biochemistry from Harvard University and received her medical degree from Harvard Medical School. She completed her radiology residency and fellowships in mammography and ultrasound at the University of California, San Francisco Medical Center. Dr. Chen was among the first to bring breast MRI and MRI-guided breast biopsy to the Glendale community and works with most advanced technology available in breast imaging. She is one of the local imaging experts in the detection and diagnosis of breast cancer.


Michele Cosgrove, MD


Dr. Cosgrove is medical director and chair of the College of American Pathologists Accredited Clinical Laboratory and Pathology Department. A graduate of the University of California, San Diego School of Medicine, Dr. Cosgrove received residency and fellowship training at the University of Southern California-Keck School of Medicine, where she currently holds appointment as associate clinical professor of pathology. She is certified by the American Board of Pathology in Anatomic and Clinical Pathology, with subspecialty certification in cytopathology. She has authored and co-authored numerous pathology publications. She is a specialist in performing and interpreting fine needle biopsies of the breast as well as other sites. Dr. Cosgrove and her colleagues share extensive experience and expertise in all aspects of women’s pathology, both breast and gynecologic.


Dennis Holmes, MD, FACS

Breast Surgery

Dr. Holmes is an internationally-renowned breast surgeon specializing in the surgical treatment of breast cancer and non-cancerous breast conditions. He is a sought-after authority on breast cancer surgery, cryoablation (tumor freezing), and radiation therapy. He completed his medical education at Tulane University School of Medicine, as well as a residency in general surgery at the University of San Francisco-East Bay and a fellowship in breast surgery at the University of Southern California. Dr. Holmes is a warm, caring breast surgeon who possesses the experience, empathy and patience to help each patient find a breast cancer solution that suits her physically and emotionally, while providing the best possible cancer control.


Simon Keushkerian, MD

General Surgery

Dr. Keushkerian received his medical degree from the American University of Beirut -Lebanon in 1981. He completed his general surgery residency at the University of Kansas. Throughout his 26 years in Glendale as a general surgeon, Dr. Keushkerian has performed many breast surgeries and is highly experienced in several types of common breast surgeries. Additionally, he dedicates time to serve the needy with yearly medical and surgical missions to Peru, Armenia, the Philippines and Malawi. He is board certified in general surgery and is the present Chief of Staff at Adventist Health Glendale.


Sara Kim, MD

Radiation Oncology

Dr. Kim is the medical director of the Radiation Oncology department at Glendale Adventist Medical Center. She brings experience and compassionate care to the Cancer Center as a board-certified radiation oncologist since 2003. Dr. Kim graduated from the University of California, Berkeley and received her medical degree from the University of Alabama School of Medicine. She completed her radiation oncology residency at Los Angeles County-University of Southern California. Since 2005, Dr. Kim has been a member of the Board of Directors for the Southern California Radiation Oncology Society and the Continuing Education Committee for Los Angeles Radiologic Society. She also serves as secretary for the Korean American Society of Therapeutic Radiation Oncology (KASTRO).


Sepideh Saber, MD

Plastic, Reconstructive & Hand Surgery

Dr. Saber is a board certified, highly trained plastic surgeon with expertise in aesthetic and reconstructive surgery, with a special interest and expertise in breast reconstruction. Dr. Saber earned her MD from Stanford and graduated from a rigorous integrated Plastic & Reconstructive Surgery residency at USC. She then completed an advanced sub-specialty fellowship in hand and microsurgery at NYU.

Her extensive training has provided Dr. Saber the expertise to bring the latest surgical techniques, including micro surgery to her work in breast reconstruction. Dr. Saber’s empathetic and conscientious approach allows her to build close connections and trust with her patients and achieve the best possible outcome.


Mihran Shirinian, MD


Dr. Shirinian has been practicing at Adventist Health Glendale for 23 years, specializing in hematology and oncology. He received his medical degree from the University of Cairo and completed his internship and residency at Cook County Hospital in Chicago, Illinois. He completed his fellowship at the University of Texas, MD Anderson Cancer Center, where he served as an instructor for two years and an assistant professor for an additional two years before moving to Glendale.

Learn more about the Cancer Center at AHGL. For a referral to one of our Breast Cancer Program physicians, call (818) 409-8000.