Williams Cancer Institute

The Williams Cancer Institute Medical Team

Dr. Jason R. Williams

President and Director of Interventional Oncology and Immunotherapy at WCI

Jason R. Williams is a medical doctor, board-certified radiologist, image-guided cancer specialist, researcher, and professor.

He is one of the pioneers of immunotherapy, specializing in intra-tumoral interventions. He performed the world’s first ablation procedure and implemented an intra-tumoral injection of a specific combination of immunotherapy agents, thus leveraging the actual process of ablation as an immunotherapy agent itself. Since then, he has performed thousands of procedures many of them “first in human” in multiple areas of ablation and cryoablation therapies.

Dr. Williams is the Director of Interventional Oncology and Immunotherapy at the WCI, where he has been advancing the use of intra-tumoral immunotherapy. He is also an adjunct professor at Case Western Reserve University in Cleveland, Ohio, where he is helping to further cutting-edge research. In addition, he is actively involved in private research combining numerous different immunotherapy agents for image-guided intra-tumoral injection covering almost all cancer types.

He and his wife, Stefanya Williams live between Los Cabos, Baja California, and Los Angeles, California.

Dr Williams started doing ablation in the early 2000s in his university. Then the need of creating an institute started to become more evident, but the process was not easy.

Williams Cancer Institute started in a difficult time because there was lack of approval, lack of insurance coverage and the hospitals were not receptive. In 2014, we started doing procedures mainly in the US. We have offices in Florida and California and facilities in Cabos San Lucas and Mexico City in Mexico. Williams Cancer Institute was called Image Guided Cancer Specialist at that moment. It was at the same time when Dr. Williams was writing our book The Immunotherapy Revolution. It ultimately changed to Williams Cancer Institute and now we have three facilities in between Mexico and the US, having the best team ready to save cancer patients’ lives.

We´re also looking to keep growing and we hope to get more facilities around the world, someday we want to achieve the dream of Dr. Williams to see cancer become a distant memory from the past.

Dr. Carlos Vargas

Chief of imaging Officer at WCI

Dr. Carlos A. Vargas, with 19 years of experience in both diagnostic studies and image-guided interventional procedures, board certificated by the College of Radiology and Imaging of Mexico City.

He graduated from the medical school at La Salle University in Mexico City in 1998 and has specialized in Radiology and Imaging in 2000.

Since 2003 he had been practicing diagnostic and interventional radiology. He has a master’s degree in hospital administration. He also has interest in teaching with more than 15 years experience in undergraduate courses at private universities as La Salle and Anahuac Universities.

He has been chief of radiology departments in several private hospitals in Mexico City such as San Angel Inn Chapultepec and Diomed.

Co-author in several publications in the field of interventional radiology such as:

1. Tratamiento Endovascular Del Aneurisma de Aorta Abdominal. Vision de la Radiología Intervencionista. Acta Médica Grupo áNgeles a (2206) v (4) N (4) – Octubre-Diciembre

2. Procedimientos Intervencionstas en vías Biliares. Acta Medica Grupo áNgeles a (2006) v (4) N (3) – Julio-Septiembre

3. Nefrostomia Percutánea. Acta Médica Grupo áNgeles a (2006) v (4) N (3) – Julio-Septiembre

4. Filtros en Vena Cava Inferior. Acta Médica Grupo áNgeles a (2206) v (4) N (2) – Abril-Junio

5. Aneurisma de Aorta Abdominal. Acta Medica Grupo áNgeles a (2203) v (1) N (2) – Abril-Junio

Eduardo Cortes

Chief Medical Officer at WCI

Eduardo Cortes studied biomedical engineering in Mexico City at Universidad Iberoamericana with a passion for improving patient outcomes in the field of oncology.

Since January of 2016, Eduardo has been an integral member of the Williams Cancer Institute team, where he works to further develop and implement solutions to improve cancer treatment alongside Dr Williams.

Eduardo’s commitment to patients is evident in everything he does. He is known for his compassionate approach to care and his ability to connect with patients on a personal level, ensuring that medical staff and care are provided in the best possible way.

As Medical Director of the Williams Cancer Institute, he plays a crucial role in patient care and medical coordination. Eduardo’s expertise lies in Intratumoral Immunotherapy and has been instrumental in implementing this innovative treatment approach at the institute.

He is extremely excited about the future of cancer research and is dedicated to making a positive impact on patients’ lives. He is committed to continuing his education and professional development to stay at the forefront of the field.

When he’s not working, Eduardo enjoys spending time with his family and training for his next triathlon.

Dr. Jesus Barrera

Medical Doctor and Anesthesiologist at WCI

Dr. Jesus A. Barrera Peralta is originally from the state of Baja California Sur, born in the town of Santa Rosalia in the municipality of Mulegé in the north of the state, from a very young age he migrated to the state of Baja California to pursue his medical degree at the University Xochicalco Campus Ensenada, where he graduated satisfactorily with honors in 2009.

He concluded his postgraduate studies in Anaesthesiology in 2014, graduating from the High Specialty Medical Unit of the National Medical Centre of the West in Guadalajara, Jalisco and has more than 10 years of experience in the field of Anaesthesiology. Concerned about public health on the eve of helping those most in need, he participated as Coordinator, Assistant Director and Medical Director in various hospitals and Deputy Director and Medical Director in different public hospitals in the town of Cabo San Lucas in Baja California Sur, Mexico until 2021. He is currently an active member of the College of Anaesthesiology in the state of Baja California Sur and Federated since 2014.

He is an anaesthesiologist in the Neuro Spine and Pain Clinic and a staff member in the Hospital H+ Los Cabos since 2018, participating in various surgical branches.

Two years ago he received the invitation to participate in WCI where he says he saw an area of opportunity to help people with cancer in advanced stages and little chance of life in the short term. His goal to help Dr. J Williams being his greatest achievement, he provides security and confidence to all our patients from their admission, during the treatment provided by Dr. J. Williams and later in the area of satisfactory recovery with the best of experiences for patients, leaving their treatment in the best possible conditions.

Dr. Ramon Sanchez

Medical Surgeon – Diagnostic and Therapeutic Imaging Specialty at WCI

Dr. Ramon Alfonso Sanchez Sanchez, a distinguished interventional radiologist, has built an exemplary career through dedicated service, innovative research, and a commitment to excellence in patient care. After graduating from Universidad La Salle in Mexico City, Dr. Sanchez achieved national recognition by securing the 3rd place in Mexico’s national residency exam for radiology. He undertook his residency at Manuel Gea Gonzalez General Hospital, completing a four-year program in radiology. Throughout his residency, Dr. Sanchez contributed to both national and international meetings, earning recognition and awards for his work.

In his third year of residency, he was appointed as Chief of the Radiology Residency Program, demonstrating early leadership qualities. Dr. Sanchez further specialized in interventional radiology and interventional oncology at the Instituto Nacional de Cancerología (INCAN) in Mexico, a leading center for cancer research and treatment. After completing his training, he continued at INCAN for two additional years as an attending physician, focusing on training new doctors and treating patients with oncological diseases.

Seeking new challenges, Dr. Sanchez accepted the position of Chief of Interventional Radiology at HRAEI Hospital, a tertiary care facility in Mexico, where he was involved in resident education and collaborated closely with oncologists on treating cancer patients. His pursuit of innovation led him to Los Cabos, where he took on the role of Chief of Radiology at H+ Hospital. There, he met Dr. Jason Williams and began collaborating on cutting-edge oncological therapies at the Williams Cancer Institute. For the past 18 months, Dr. Sanchez has been instrumental in advancing image-guided intratumoral therapies and cryoablation procedures.

Dr. Sanchez is an accomplished author and co-author in the field of interventional radiology, with notable publications including:

  1. “Punción y drenaje de colecciones toracoabdominales en servicios de radiología intervencionista” (Puncture and drainage of thoracoabdominal collections in interventional radiology services) in Anales de Radiología México, January 2016.
  2. “Coriocarcinoma en un paciente con antecedente de enfermedad trofoblástica: reporte de caso y revisión de la literatura” (Choriocarcinoma in a patient with a history of trophoblastic disease: case report and literature review) in Anales de Radiología México, January 2016.
  3. “Mucormicosis diseminada. Presentación de caso y revisión de la literatura” (Disseminated Mucormycosis. Case presentation and literature review) in Anales de Radiología México, January 2016.


Dr. Sanchez’s dedication to his field, coupled with his significant contributions to interventional radiology, position him as a leader and innovator in cancer treatment and radiology education

Executive Team

Dr Jason Williams
President and Director of Interventional Oncology and Immunotherapy at WCI
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Stefanya Williams
Chief Executive Officer (CEO)
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Eduardo Cortes
Chief Medical Officer at WCI
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Julian Ramirez
Chief Operating Officer (COO)
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Dr. Carlos A. Vargas
Specialist of cryoablation and image-guided intratumoral therapies at WCI
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Angie Holder
Executive Assistant
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Vanesa Ramirez
Chief Marketing Officer
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Julian Lopez
Chief Financial Officer
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Dr. Jason R. Williams Credentials

Medical School: Louisiana State University Health Sciences Center.

Internship: Internal Medicine, University South Alabama.

Residency: Radiology, University of South Alabama.
Certifications and Additional

Training: Board Certified by American Board of Radiology, Interventional Oncology, Interventional Spine, Nuclear Medicine.

MQSA (Breast Imaging), ACLS, PALS.

Adjunct Professor: Case Western Reserve University, Cleveland, OH.

Radiological Society of North America Resident/Fellow of the year award 2002.

2007 Telly award.


Combined use of image guided ablation with immune checkpoint inhibitors, Ipilimumab and Nivolumab (anti CTLA-4 and PD-1).

Intra-tumoral PV-10 combined with cryoablation and AblationVax.

Intra-tumoral Toll-like receptor agonist (TLR) imiquimod and CpG combined with Cryoablation and immune checkpoint inhibitors.

Implantable IDO inhibitor pellet (Indoximod) combined with Cryoablation and immune checkpoint inhibitors.

Intra-arterial 3-bromopyruvate combined with intra-arterial immune checkpoint inhibitors Ipilimumab and Nivolumab.

Intra-arterial hepatic infusion of immunotherapy, Nivolumab and Ipilimumab.

Cryoablation of cancer combined with intra-tumoral injection of Montanide.