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.