651 a Meta-Analysis of Survival After Neoadjuvant Chemoradiotherapy Versus Neoadjuvant Chemotherapy in Resectable Locally Advanced Esophageal Cancers Based on Histologic Subtypes

Abstract

Neoadjuvant treatments provided survival benefits over surgery alone in resectable locally advanced esophageal and esophagogastric junction (EGJ) cancer patients. Both neoadjuvant chemoradiotherapy (nCRT) and neoadjuvant chemotherapy (nCT) are shown to be effective treatments. However, the direct comparison between two methods based on histologic subtypes, squamous cell carcinoma (SCC) and adenocarcinoma (AC) is still limited. This study examined the hypothesis that nCRT could provide the better overall survival (OS) than nCT. Methods A comprehensive search of studies comparing nCRT and nCT in patients with esophageal and EGJ cancer based on histologic subtypes was conducted. A meta-analysis of randomized (8 articles) and non-randomized (15 articles) studies was performed using odds ratio (OR) and 95% confidence intervals (CI95%). The OS was the main objective, whereas the secondary objective were complete pathological response (pCR) rate, curative resection (R0) rate, locoregional progression free-survival (L-PFS) rate, postoperative complications and mortality. Results Twenty three articles included 1,671 SCC and 9,285 AC patients. Neither 3- nor 5-year OS was found to be different. However, SCC patients receiving nCRT showed the better 3-year OS (OR 1.67, CI95% 1.17–2.40, p = 0.005). Both pCR and R0 rates were superior in nCRT group (OR 3.30, CI95% 2.46–4.44 and 2.46, CI95% 1.66–3.65, p < 0.00001, respectively). The better 3-year L-PFS was observed in nCRT group (OR 1.47, CI95% 1.17–1.85, p = 0.008), but 5-year L-PFS was comparable. The 30-day mortality was comparable, while 90-day mortality was higher in nCRT group (OR 1.32, CI95% 1.01–1.72, p = 0.04). Conclusion The nCRT provided the better overall survival especially in SCC patients and also increased locoregional control. Meanwhile, postoperative complications and mortality were higher after nCRT. Due to clinical heterogeneity, the multidisciplinary team management for each patient is required before treatment.