McALLEN
Billie J. Marek, MD, FACP
Medical Oncology/Hematology
Dr. Marker is board-certified and specializes in medical oncology and heamatology. He currently serves as
a director of Texas Oncology and is the medical director for Texas Oncology-McAllen. He has served the Rio
Grande Valley for the past 22 years as a medical oncologist and hematologist, has been recognized as a
“Super Doctor” in oncology for five years in a row, and was recognized as Doctor of The Year for Rio
Grande Regional. Dr. Marek received his medical degree from The University of Texas Medical School at
San Antonio. He completed his fellowship at The University of Texas M. D. Anderson Cancer Center.
Alvaro Restrepo, MD
Medical Oncology/Hematology
“I can be part of your team... and together we can fight the battle.” Dr. Restrepo specializes in, medical
oncology and hematology. He completed his fellowship at the University of Miami. He also serves on the
reast Cancer Committee of US Oncology and has completed a fellowship in breast cancer treatment.
Through the Life Beyond Cancer Fundation he established the Texas Oncology–McAllen Breast Cancer
Ride/Walk undraiser to raise funds for Rio Grande Valley cancer patients. To date approximately $30,000 has
been donated to cancer patients in the Rio Grande Valley.
Suresh Ratnam, MD, FACP
Medical Oncology/Hematology
Dr. Ratnam has been with Texas Oncology-McAllen for 13 years, which he joined after completing his
fellowship at the renowned National Cancer Institute at the National Institutes of Health. He has
co-authored several research publications and is passionate about cutting-edge oncology care. He currently
serves on the Pharmacy and Therapeutics Committee of US Oncology and chairman of the Credentials
Committee for South Texas Health System.
Guillermo Lazo, MD
Medical Oncology/Hematology
Dr. Lazo specializes in medical oncology and hematology. He completed his fellowship at The University of
Texas MD Anderson Cancer Center. He is a recipient of several awards including the American Society of
Clinical Oncology Merit Award and is the author of several peer-reviewed medical publications as well as
book chapters. He received the highest honors on the professional examination for his medical doctorate
degree.
McAllen 1901 South 2nd Street McAllen, Texas 78503 PH: 956.687.5150 FAX: 956.687.9546
www.TexasOncology.com