SBRT Offers Short-Term Improvements Over Surgery in Early-Stage NSCLC

CT scan of lung cancer patient. Image © bendao / Shutterstock.com

Though surgery is the standard treatment for early-stage non–small-cell lung cancer (NSCLC), a new study suggests that stereotactic body radiotherapy (SBRT) offers lower immediate mortality and toxicity. Over the longer term, however, there is benefit with surgery over SBRT.

“Outcomes from SBRT are so promising that some investigators are beginning to advocate its use even in patients eligible for surgery, although this remains controversial,” wrote study authors led by James B. Yu, MD, MHS, of Yale School of Medicine in New Haven, Connecticut. “However, despite the increasing adoption of SBRT, its comparative effectiveness in comparison with surgery remains unknown.”

To fill that gap, researchers performed a retrospective cohort study using patients in the SEER-Medicare linked database. They included 367 patients with stage I NSCLC who underwent SBRT, and 711 matched surgery patients; all patients were 67 years or older. Results were published online ahead of print in Cancer.

Acute toxicity, representing complications that took place within 1 month of treatment, was lower in the SBRT group than the surgery group, at 7.9% vs 54.9% (P < .001). In particular, there were higher rates of infections and respiratory complications in surgery patients. After 24 months, however, there was no difference in toxicity, at 69.7% for SBRT and 73.9% for surgery (P = .31). The incidence rate ratio (IRR) for toxicity from SBRT vs surgery did show a difference, at 0.74 (95% CI, 0.64-0.87).

At 3 months after treatment, the overall mortality rate was 2.2% with SBRT and 6.1% with surgery (P = .005). Again, after 24 months, that difference disappeared, and in this case the advantage shifted to surgery (40.1% vs 22.3%; P < .001).

The researchers also divided the participants into two groups based on life expectancy. In those with short life expectancy (less than 5 years), there was no difference in lung cancer mortality, with an IRR of 1.01 (95% CI, 0.40-2.56). In those with longer life expectancy, however, SBRT was linked to a greater overall mortality than surgery, with an IRR of 1.49 (95% CI, 1.11-2.01). There was also a trend toward higher lung cancer mortality in those patients with SBRT, but it did not reach significance.

The researchers wrote that these results support current practice patterns involving the increasing use of SBRT in patients with comorbidities or advanced age.

“These findings highlight the importance of patient life expectancy to the relative impact of treatment and can inform the interpretation of future comparisons of SBRT and surgery,” the authors wrote. “For example, if clinical trials demonstrate improved survival with surgery, it may be due in part to the inclusion of healthier patients with longer life expectancies.”