Stereotactic ablative radiotherapy demonstrated efficacy and noninferiority to surgery as a treatment option for patients with operable stage I non–small cell lung cancer, according to the results of a pooled analysis.
“Stereotactic radiation therapy is a relatively new approach for operable early-stage lung cancer, while surgery has been the standard for a century,” Joe Y. Chang, MD, PhD, professor of radiation oncology at The University of Texas MD Anderson Cancer Center, said in a press release. “This study can give physicians confidence to consider a noninvasive option.”
Lobectomy with mediastinal lymph node dissection or sampling currently serves as the standard of care for patients with operable stage I NSCLC, according to study background. Stereotactic ablative radiotherapy previously demonstrated positive outcomes in patients with inoperable stage I NSCLC; however, two previous randomized phase 3 studies of stereotactic ablative radiotherapy in patients with operable stage I NSCLC — the STARS and ROSEL studies — closed early due to slow enrollment.
Chang and colleagues conducted a pooled analysis using data from these previous studies.
The previous studies had enrolled 58 patients (median age, 67.3 years) with operable stage I NSCLC and researchers randomly assigned them to receive stereotactic ablative radiotherapy (n = 31) or surgery (n = 27).
OS served as the primary endpoint. RFS and grade 3 or higher adverse events served as secondary endpoints.
Median follow-up was 40.2 months (interquartile range [IQR], 23-47.3) for the combined stereotactic ablative radiotherapy arms and 35.4 months (IQR, 18.9-40.7) in the combined surgery arms.
The researchers observed six deaths in the surgery cohort, compared with one death in the stereotactic ablative radiotherapy cohort. Researchers estimated a 3-year OS rate of 95% among patients receiving stereotactic ablative radiotherapy, compared with 79% among patients who underwent surgery (HR = 0.14; 95% CI, 0.01-1.19).
Researchers observed a 3-year RFS rate of 86% in the stereotactic ablative radiotherapy arm and 80% in the surgery arm (HR = 0.69; 95% CI, 0.21-2.29). One surgical patient experienced regional nodal recurrence and two surgical patients experienced distant metastases.
Ten percent of patients in the stereotactic ablative radiotherapy arm experience a grade 3 treatment-related adverse event, including chest wall pain (n = 3), dyspnea or cough (n = 2) and fatigue and rib fracture (n = 1). Researchers observed no grade 4 treatment-related adverse events or treatment-related deaths in this arm.
One patient in the surgery arm died from surgical complications, and 44% of patients in this cohort experienced a grade 3 or 4 adverse event. The most commonly reported adverse events included dyspnea (n = 4), chest pain (n = 4) and lung infections (n = 2).
The researchers acknowledged the small sample sizes and premature study closures as limitations of their study.
“For the first time, we can say that the two therapies are at least equally effective, and that stereotactic ablative radiotherapy appears to be better tolerated and might lead to better survival outcomes for these patients,” Chang said.
The results of this pooled analysis point to the need for further evaluation of nonsurgical treatments for lung cancer, Tom Treasure, MD, of the clinical operational research unit at University College London, Robert C. Rintoul, PhD, FCRP, of the department of thoracic oncology at Papworth Hospital in Cambridge, United Kingdom and Fergus Macbeth, MD, of the Wales Cancer Trials Unit, wrote in an accompanying editorial.
“The opportunity of a fair test should be given to less invasive treatments,” Treasure, Rintoul and Macbeth wrote. “Stereotactic ablative radiotherapy is not the only candidate procedure that might reduce the harms of lung cancer treatment without loss of effectiveness. The uptake of videothoracoscopy, for example, has been resisted by surgeons, but the accumulating case series and registry evidence suggest that oncological effectiveness is not sacrificed by moving away from thoracotomy.”
Doctors and patients should hold each other accountable and work toward determining the most effective and least harmful surgery, they concluded.
“Clinicians have an ethical imperative to obtain evidence rather than continue to perpetrate needless harm through ignorance,” Treasure, Rintoul and Macbeth wrote. “Patients, too, have a societal duty to participate in carefully planned and monitored trials.” – by Cameron Kelsall
Disclosure: The researchers report no relevant financial disclosures. Treasure, Rintoul and Macbeth report no relevant financial disclosures.