Background: The survival benefit of neoadjuvant therapy in resectable carcinoma esophagus has been elucidated. We performed a meta-analysis in light of new studies and long-term results of past trials. The search strategy was refined to include only "neoadjuvant" so that any bias by adjuvant treatment is eliminated.
Methods: A detailed search of MEDLINE, Embase, and Cochrane Library was done. Only published randomized English language trials were included. Data were categorized as neoadjuvant concurrent chemoradiation (NACRT), neoadjuvant chemotherapy (NACT), neoadjuvant radiotherapy (NART), and neoadjuvant sequential chemoradiotherapy (SCRT). Meta-analysis was done using odds ratio (OR) and 95% CI using fixed/random effects model. Heterogeneity was tested by chi-square and I2 test. Z probability calculated significant difference across subgroups. Outcomes assessed were overall survival (OS) and disease-free survival (DFS) at 3 and 5 years, respectively, mortality (30/90 day) and failures (local/systemic).
Results: Twenty-five randomized trials involving 5272 patients were included for quantitative analysis. NACRT was evaluated in 12 studies (2676 patients). Superior 3-year OS (OR = 0.68 CI 0.52-0.90, p = 0.007), 3-year DFS (OR = 0.55 CI 0.45-0.68, p = 0.00001), and 5-year DFS (OR = 0.59 CI 0.47-0.74, p = 0.00001), with lower failures (OR = 0.52 CI 0.37-0.73, p = 0.0001), were seen in favor of NACRT at the cost of increased perioperative mortality (OR = 1.79 CI 1.15-2.80, p = .01). However, 5-year OS (OR = 0.78 CI 0.60-0.1.01, p = 0.06) was not found to be significantly superior. NACT, NART, and SCRT were not found to have any benefit over surgery alone.
Conclusion: This meta-analysis presents strong evidence favoring NACRT over upfront surgery. It also shows no survival advantage of neoadjuvant chemotherapy.
Keywords: Carcinoma esophagus; Neoadjuvant chemoradiation; Neoadjuvant chemotherapy; Neoadjuvant radiation; Preoperative chemoradiation; Preoperative chemotherapy; Sequential chemoradiation.