Unresectable, Primary NSCLC: Is SBRT of Benefit in Combination With Conventional Therapy?

By: Amy MacDonald, MS
Posted: Tuesday, December 17, 2024

John H. Heinzerling, MD, of Levine Cancer Institute, Atrium Health, Charlotte, North Carolina, and colleagues examined the use of stereotactic body radiotherapy (SBRT) followed by lymphatic mediastinal chemoradiotherapy and immunotherapy in patients with locally advanced, unresectable non–small cell lung cancer (NSCLC). Their phase II, multicenter, single-arm trial was published in The Lancet Oncology. The researchers’ data suggest that although the study did not meet its primary endpoint (1-year progression-free survival), this combination therapy should be investigated further, since it may offer therapeutic activity while not increasing toxicity.

A total of 61 patients from 8 cancer centers were enrolled between May 2017 and June 2022. Of them, 59 patients were evaluable for 1-year progression-free survival. Patients received at least one fraction of SBRT to their primary tumor (50–54 Gy in 3–5 fractions), followed by conventional radiation (30 2 Gy fractions, to a maximum of 60 Gy) and concurrent platinum doublet chemotherapy. In addition, consolidation use of the anti–PD-L1 monoclonal antibody durvalumab was permitted for any patients without disease progression after chemoradiotherapy.

A total of 37 patients of the initial 59 were alive and evaluable at 1 year. A 1-year progression-free survival rate of greater than 60% was statistically required to reject the null hypothesis. The progression-free survival rate in these 37 patients was 62.7% (90% confidence interval = 51.2%–73.2%; one-sided P = .39, compared with the historic control), falling short of statistical significance. However, since this phase II trial represented the largest prospective evaluation of the addition of full-dose SBRT in this patient population, and the 5-year survival rate with current therapies still remains poor, a randomized phase III trial is ongoing.

Disclosure: For full disclosures of study authors, visit thelancet.com.

The Lancet Oncology

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