For patients with early-stage non–small-cell lung cancer (NSCLC) who had positive margins following lobectomy, additional radiation therapy was not associated with a long-term survival benefit in a recent retrospective study.

Positive margins were associated with significantly worse 5-year survival in the study of patients with stage I-II NSCLC, which was published in the Journal of Surgical Research (2018 Mar. doi: 10.1016/j.jss.2017.10.025 ).

The study is one of the latest to suggest radiation may not be of benefit for treatment of positive margins after surgical resection of lung cancer, according to Brian C. Gulack, MD, MHS, department of surgery, Duke University, Durham, N.C., and his coauthors.

“Our analysis adds important findings to the literature as it focuses specifically on patients undergoing a lobectomy for stage I or II disease,” they wrote.

Adjuvant radiation therapy and re-resection are considered to be two potential treatment options for patients with NSCLC who undergo lobectomy and have positive margins, wrote Dr. Gulack and his coauthors.

However, guidelines from the National Comprehensive Cancer Network recommend re-resection when possible, they added.

The retrospective analysis by Dr. Gulack and his colleagues was based on information in the National Cancer Data Base, which collects data from more than 1,500 hospitals.

The investigators identified 49,563 patients with stage I-II NSCLC who received lobectomy with no induction therapy between 1998 and 2006. Of those patients, 1,934 (3.9%) had positive margins, the authors reported.

Five-year survival was 34.5% for patients with reportedly positive margins, versus 57.2% for patients without positive margins, according to results of an unadjusted analysis.

To evaluate the effects of radiotherapy specifically for treatment of positive margins, the investigators excluded patients who had upstaged disease or who had received palliative radiotherapy. Out of the remaining 1,579 patients, 579 (38.2%) received radiation therapy, according to the report.

In that group, there was no significant difference in likelihood of death associated with radiation treatment (hazard ratio, 1.10, 95% confidence interval, 0.90-1.35).

“Despite the importance of these findings, there is still potential for substantial bias in this retrospective study, and therefore prospective investigation is necessary in order to validate our results,” Dr. Gulack and his colleagues concluded.

Study coauthor Thomas A. D’Amico, MD, reported serving as a consultant for Scanlan, and the rest of the authors had no disclosures.

SOURCE: Gulack et al. J Surg Res 2018 March doi: 10.1016/j.jss.2017.10.025.