With or without consolidation chemotherapy using cisplatin/5-FU after concurrent chemoradiotherapy in stage II-III squamous cell carcinoma of the esophagus: A propensity score-matched analysis

Background and purpose: The benefit of consolidation chemotherapy for locally advanced squamous cell carcinoma of the esophagus is unknown. The aim of this study was to investigate the efficacy of consolidation chemotherapy with cisplatin and 5-fluorouracil (5-FU) after concurrent chemoradiotherapy (CCRT) with the same agents in patients with stage II-III disease.

Material and methods: Data for patients with stage II-III squamous cell carcinoma of the esophagus treated with CCRT were retroactively reviewed. Patients who received CCRT alone (observation group) were compared with those who underwent CCRT followed by consolidation chemotherapy (consolidation group) with regard to progression-free survival, overall survival, treatment failure and toxicity. Differences in baseline characteristics were adjusted using the propensity score matching method.

Results: From September 2006 to September 2012, 812 patients were recruited (n = 272 for observation; n = 540 for consolidation). Among them, 290 (35.7%) had clinical stage II disease and 522 (64.3%) had stage III disease. In the overall study cohort, the median progression-free survival (22.1 months vs. 22.0 months, P = 0.917) and median overall survival (33.8 months vs. 31.3 months, P = 0.591) were comparable between the observation group and consolidation group. Comparisons of the observation and consolidation group in the matched population (262 patients in each group) showed median progression-free survival of 23.0 months and 25.4 months (hazard ratio [HR], 0.93; 95% CI [confidence interval], 0.74-1.15; P = 0.491), and median overall survival of 34.6 months and 35.0 months (HR, 0.92; 95% CI, 0.80-1.27; P = 0.919), respectively. There were no significant differences in local/regional failure and persistence disease (50.4% vs. 48.5%) and distant failure (10.7% vs. 8.8%) between the two groups.

Conclusions: Compared to CCRT alone, consolidation chemotherapy did not further prolong progression-free survival and overall survival for patients with stage II-III squamous cell carcinoma of the esophagus. The role of consolidation therapy needs to be studied further.