ASTRO Updates Guideline on Radiation Therapy for Locally Advanced Rectal Cancer

The American Society for Radiation Oncology (ASTRO) has issued a new clinical guideline on the use of radiation therapy for treating locally advanced rectal cancer, reflecting significant advances in treatment strategies and patient selection. Published in Practical Radiation Oncology, this update incorporates findings from practice-changing clinical trials conducted since the previous guideline in 2020, offering a more nuanced approach to balancing cancer control with quality-of-life preservation.

What’s New in the Guideline?

The updated guideline introduces critical changes, including expanded criteria for stratifying patients into higher-risk and lower-risk groups, allowing for more personalized treatment. New recommendations explore both intensifying and de-intensifying therapies:

• Selective Omission of Radiation: For patients with lower-risk disease, the guideline conditionally recommends omitting pre-operative radiation therapy to reduce treatment-related side effects without compromising outcomes. Expanded criteria now help define lower-risk patients more precisely.
• Organ Preservation Options: Approaches such as total neoadjuvant therapy (TNT) followed by non-operative management (NOM) are outlined as viable alternatives to radical surgery for select patients. Recent evidence supports the safety and feasibility of these strategies for those responding well to neoadjuvant therapy.
• Intensified Treatment for High-Risk Patients: Total neoadjuvant therapy is strongly recommended for patients at higher risk of recurrence, with the aim of improving outcomes through more aggressive treatment.
• Biomarker-Driven Treatments: The guideline also highlights emerging data on immunotherapy and other biomarker-based strategies, offering new options for tailored treatment plans.

Why This Matters

Rectal cancer remains a critical public health concern, with more than 46,000 U.S. cases expected in 2024. Particularly alarming is the rise in early-onset colorectal cancer among younger adults. While the standard of care in 2020 combined pre-operative chemoradiation, surgery, and post-operative chemotherapy, recent trials underscore the importance of individualizing treatment.

The updated guideline addresses this by providing a roadmap for tailoring therapies to each patient’s unique risk profile and priorities. “These emerging treatment paradigms allow for more personalized and nuanced recommendations that are tailored to each individual patient’s level of risk as well as their priorities,” said Jennifer Y. Wo, MD, vice chair of the guideline task force. By balancing effective cancer control with quality-of-life preservation, the recommendations aim to improve outcomes and patient satisfaction.

The guideline’s multidisciplinary development, endorsed by leading oncology organizations worldwide, ensures its applicability in diverse clinical settings. Its emphasis on shared decision-making underscores the importance of aligning treatment with patient goals, a critical component of modern oncology care.