ARLINGTON, Va., November 18, 2025 — A new clinical guideline from the American Society for Radiation Oncology (ASTRO) is the first to focus on radiation therapy for patients with gastric (stomach) cancer. The recommendations outline radiation therapy’s role in multidisciplinary care, including best practices for patient selection, integration with systemic therapy and treatment delivery. The guideline is published in Practical Radiation Oncology , ASTRO’s clinical practice journal.
Gastric tumors are the fifth most common cause of cancer incidence and death globally, with more than 30,000 new diagnoses estimated in 2025 among American adults. Overall stomach cancer rates have declined over the past 50 years, though recent studies show that incidence may be increasing among middle-aged adults. Gastric cancers are often diagnosed at an advanced stage, and typically requiring coordination across radiation, surgical and medical oncology.
Treatments for patients with gastric cancer have advanced significantly over the past decade, driven by improvements in surgery, chemotherapy, immunotherapy and radiation therapy. For patients with resectable disease, perioperative chemotherapy regimens given before and after surgery have improved survival, with emerging evidence showing an additional benefit from incorporating immunotherapy. For patients who cannot receive perioperative chemotherapy, a preoperative chemoradiation approach may help achieve good local control, while definitive chemoradiation can offer a non-surgical option for those who are medically inoperable or decline surgery. Radiation therapy also plays an important palliative role in relieving gastric cancer-related bleeding, pain and other symptoms, supported by newer techniques that allow for more precise and better-tolerated treatment.
“Management of gastric cancer is complex and multidisciplinary, and the role of radiation therapy has evolved over the past two decades, requiring thoughtful and dynamic integration with the modalities of surgery, chemotherapy, immunotherapy and palliative care,” said Christopher G. Willett, MD, FASTRO, chair of the expert panel that developed the guideline and the Mark W. Dewhirst Professor of Radiation Oncology at Duke University.
“While other societies have published guidelines for treating patients with gastric cancer, this is the first guideline to clarify the role of radiation therapy across all stages of the disease, providing patient-centered, evidence-based recommendations to guide clinical practice,” said Christopher J. Anker, MD, vice chair of the expert panel and a professor of radiation oncology at the University of Vermont Cancer Center.
Key recommendations from the guideline are as follows:
Resectable Disease
Unresectable (Locally Advanced or Metastatic) Disease
Treatment Planning and Delivery
About the Guideline
“ Radiation Therapy for Gastric Cancer: An ASTRO Clinical Practice Guideline ” was developed by a multidisciplinary panel of radiation, medical and surgical oncologists, a radiation oncology resident, a medical physicist and a patient representative. Recommendations were based on a systematic review of research published from 2001 through mid-2025. The guideline was developed in collaboration with the American Society of Clinical Oncology, the European Society for Radiotherapy and Oncology (ESTRO) and the Society of Surgical Oncology (SSO), and it is endorsed by ESTRO, SSO, the Royal Australian and New Zealand College of Radiologists and the American Radium Society.
ASTRO's clinical guidelines are intended as tools to promote appropriately individualized, shared decision-making between physicians and patients. None should be construed as strict or superseding the appropriately informed and considered judgments of individual physicians and patients.
Patient Resources
ABOUT ASTRO
The American Society for Radiation Oncology (ASTRO) is the world’s largest professional society dedicated to advancing radiation oncology, with 10,000 members including physicians, nurses, physicists, radiation therapists, dosimetrists and other professionals who work to improve patient outcomes through clinical care, research, education and policy advocacy. Radiation therapy is integral to 40% of cancer cures worldwide, and more than one million Americans receive radiation treatments for their cancer each year. To learn more about ASTRO, visit our website and media center and connect with us on social media .
Practical Radiation Oncology
Systematic review
Radiation Therapy for Gastric Cancer: An ASTRO Clinical Practice Guideline
18-Nov-2025