The result of a joint effort by the American Society for Radiation Oncology and European Society for Radiotherapy and Oncology, the guidelines emphasizes the need for a multidisciplinary team approach to guide treatment decisions for oligometastatic disease.
Historically, treatment for oligometastatic NSCLC has involved systemic therapy including chemotherapy or immunotherapy, and local therapy was given only for palliation and symptom relief. But increasing evidence has demonstrated that definitive local therapy may have an additional role in controlling tumor growth and improving survival outcomes, and an increasing number of radiation oncologists and multidisciplinary teams are now using local therapy beyond palliative care for these patients, the authors noted.
“Oligometastatic NSCLC is a phase in lung cancer development that may offer us new opportunities to improve patient outcomes, because it typically is more treatable than widely metastatic cancer,” said Puneeth Iyengar, MD, PhD, cochair of the guideline task force and an associate professor of radiation oncology at UT Southwestern Medical Center, Dallas.
“The research on local therapy for oligometastatic cancer is still at a relatively early stage, but we already see indicators of potential benefits for patients. Adding local therapy to systemic therapy may lead to more durable cancer control, potentially improving progression-free survival, overall survival and quality of life,” he said in a statement.
The new guideline is published in Practical Radiation Oncology.
The purpose of this joint guideline was to provide recommendations on local therapy use for oligometastatic NSCLC, along with a summary of the evidence justifying its incorporation into standard treatment paradigms.
Key recommendations
Owing to the lack of significant randomized phase 3 trials, the guideline task force strongly recommended a patient-centered, multidisciplinary approach for all decision-making regarding potential treatment. In addition, algorithms were also created for the optimal clinical scenarios for local therapy and the different types of local therapy that are available for these patients.
Key recommendations include:
- The integration of definitive local therapy is recommended only for patients who have five or fewer distant extracranial metastases, and only when technically feasible and clinically safe for all disease sites. Definitive local therapy is also conditionally recommended for carefully selected patients with synchronous oligometastatic, metachronous oligorecurrent, induced oligopersistent, or induced oligoprogressive conditions for extracranial NSCLC.
- Radiation and surgery are the only recommended modalities for definitive local treatment of oligometastatic NSCLC. Radiation is favored when multiple organ systems are being treated or when the clinical priority is to minimize breaks from systemic therapy, whereas surgery is favored when large tissue sampling is needed for molecular testing to guide systemic therapy.
- For sequencing and timing, there is an emphasis on upfront, definitive local treatment for symptomatic metastases. For asymptomatic patients with synchronous disease, at least 3 months of standard-of-care systemic therapy is recommended before starting definitive local therapy.
- For optimal staging, radiation dosing, treatment planning, and delivery techniques, there is a preference for hypofractionated radiation therapy or stereotactic body radiation therapy when appropriate. The task force also emphasizes the importance of appropriate imaging and comments that it “cannot be overstated” to diagnose oligometastatic disease; they recommend that care teams consult guidelines from groups such as the National Comprehensive Cancer Network and the European Organisation for Research and Treatment of Cancer.
- Patients who develop disease progression at a limited number of sites, so-called oligoprogression at previously treated sites, and/or de novo recurrences at new sites may benefit from repeat local definitive therapy performed with the aim of prolonging progression-free survival or delaying a switch in systemic therapies.
Matthias Guckenberger, MD, cochair of the guideline task force and a professor and chairman of radiation oncology at the University Hospital Zürich, cautioned that “despite the widespread enthusiasm in the field of oligometastatic disease, the quality of evidence supporting the integration of definitive local therapy into a multimodality treatment strategy is still lower as compared to indications such as locally advanced NSCLC.”
“To compensate for this lack of highest-quality evidence, recommendations of this guideline were established by a broad consensus involving experts from ASTRO and ESTRO, colleagues from the fields of thoracic surgery and medical oncology and a patient representative,” Dr. Guckenberger said in a statement.
The guideline task force also emphasized the need for equitable use of these techniques, noting that “a significant effort must be taken to ensure that the decisions regarding the use of local therapies for oligometastatic NSCLC be applied equally across all patients to avoid any health disparities.”
This work was funded by ASTRO. Dr. Iyengar reported no disclosures. Dr. Guckenberger reports relationships with the European Thoracic Oncology Platform, Varian, ViewRay, and ESTRO. Several of the coauthors disclosed relationships with industry.
A version of this article first appeared on Medscape.com.