Purpose
To evaluate differences in pathologic complete response (pCR) rates and overall survival among patients receiving either neoadjuvant chemotherapy or chemoradiation prior to esophagectomy for locally advanced esophageal cancer.
Patients and methods
Esophageal cancer patients receiving either neoadjuvant chemotherapy or chemoradiation prior to esophagectomy were identified using the National Cancer Data Base (NCDB). Univariate analysis compared patient, tumor, and postoperative outcome characteristics. Logistic regression was performed to identify variables associated with achieving pCR. Kaplan-Meier analysis was performed to compare overall median survival by neoadjuvant therapy type and pCR status. Finally, a Cox proportional hazards model was fitted to identify variables associated with increased mortality hazard.
Results
From 2006 – 2012, 916/7,338 (12.5%) of patients received neoadjuvant chemotherapy while 6,422 (87.5%) received neoadjuvant chemoradiation. Neoadjuvant chemoradiation patients were more likely to achieve pCR (17.2% versus 6.4%, p<0.001) and less likely to have positive margins (5.6% versus 11.5%, p<0.001) than neoadjuvant chemotherapy patients, with no difference in 30- or 90-day mortality. Achieving pCR was associated with improved overall median survival (59.5 months ± 4.0 versus 30.1 months ± 0.76 for those with persistent disease, p<0.001). On logistic regression, neoadjuvant chemoradiation therapy was independently associated with achieving pCR (Odds Ratio 2.75, 2.01 – 3.77, p<0.001). Despite improvement in pCR rate with neoadjuvant chemoradiation, neoadjuvant therapy type was not independently associated with long-term survival (HR 1.12, 95% CI 0.97 – 1.30, p=0.12).
Conclusion
While neoadjuvant chemoradiation is more successful in downstaging esophageal cancer prior to esophagectomy, this therapy was not independently prognostic for improved long-term survival. Other factors affecting long-term survival among pathologic complete responders and among patients with persistent disease should be investigated to clarify this association.