Acknowledgments
The data used in the study are derived from a de-identified NCDB file. The American College of Surgeons and the Commission on Cancer have not verified and are not responsible for the analytic or statistical methodology employed, or the conclusions drawn from these data by the investigator. Preliminary results of this study were presented at the 2018 American Society of Clinical Oncology Annual Meeting, June 1–5, Chicago, IL.
Potential conflict of interest
Disclosure forms provided by the authors are available with the full text of this article online at https://doi.org/10.1080/10428194.2018.1480776