Dr Hales on the Use of Post-Operative Radiotherapy in NSCLC

“Right now, based on the randomized data we have, we have insufficient [information] to guide the routine use of PORT in [patients with resected stage III NSCLC]. That being said, there are subsets of patients that probably benefit from radiation.”

Russell Hales, MD, director, Thoracic Oncology Multidisciplinary Program, associate professor, clinical radiation oncology and molecular radiation sciences, and director, thoracic multidisciplinary clinic, John Hopkins University School of Medicine, discusses clinical data that challenge the use of post-operative radiotherapy (PORT) in patients with non–small cell lung cancer (NSCLC).

The phase 3 Lung ART (NCT00410683) and PORT-C (NCT00880971) trials both investigated the role of adjuvant radiotherapy in patients with resected stage III NSCLC, Hales begins. Lung ART did not demonstrate a significant improvement in disease-free survival or overall survival with PORT, he says. However, the study primarily used 3-dimensional conformal radiation therapy, a technique that is largely outdated in contemporary clinical practice, he explains. This approach likely resulted in increased radiation exposure to healthy tissues, including in the heart and lungs, which may have contributed to a higher incidence of cardiovascular events and ultimately negated the potential benefit derived with radiotherapy, he emphasizes.

In contrast, the PORT-C trial used more advanced intensity-modulated radiation therapy, which allows for greater precision in radiation delivery and reduces toxicity to surrounding organs, Hales notes. However, a significant limitation of the PORT-C trial was that 23.9% of patients who were randomly assigned to receive radiation did not undergo the study treatment, thereby introducing a significant protocol adherence issue that complicates data interpretation, he reports. When analyzing outcomes based on treatment assignment, investigators observed no clear benefit with adjuvant radiotherapy, according to Hales. However, an analysis based on actual treatment received suggested a potential advantage with PORT, he states.

Given the conflicting results with PORT in the literature, the extrapolation of data from these trials into clinical practice remains challenging, Hales says. Although the randomized trial data do not provide sufficient evidence to support the routine use of PORT in all patients with resected stage III NSCLC, certain patient subsets might still derive benefit from this treatment approach, he concludes.