ABSTRACT
Introduction
Usually, clinical trials on esophageal cancer exclude patients with a prior malignancy, assuming that this may influence survival outcomes. However, little is known about the impact of a prior malignancy on its prognosis.
Methodology
The Surveillance, Epidemiology, and End Results database (SEER) was used to review patients with stage IV squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the esophagus during 1973–2014. We calculated overall and esophageal cancer-specific survival using unadjusted Kaplan-Meier and multivariable covariate-adjusted Cox models.
Results
A total of 7,807 patients with stage IV SCC, and 11,238 patients with stage IV AC were reviewed, of which 652 and 840 patients, respectively, had a prior malignancy. Kaplan-Meier curves did not show difference in overall survival of SCC or AC in patients with prior malignancy. Stage IV AC patients with prior malignancy did not show different esophageal cancer-specific survival. However, esophageal cancer-specific survival was better among stage IV SCC patients with prior malignancy. Similar results were observed in Cox models after adjustment for: age, sex, race, marital status, grade, site in esophagus, and undergoing surgery.
Conclusion
Prior malignancy does not adversely impact survival of stage IV esophageal cancer. These results should be taken into consideration when designing clinical trials.
Acknowledgments
We would like to thank Saad L. Janoudi for his help in data preparation.
Declaration of interest
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Supplementary material
Supplemental data for this article can be accessed here.