The significance of consolidation chemotherapy after concurrent chemoradiotherapy in esophageal squamous cell carcinoma: a randomized controlled phase III clinical trial.

Background: This study explored the significance of consolidation maintenance chemotherapy after concurrent chemoradiotherapy with different regimens in patients with esophageal squamous cell carcinoma.

Method: A prospective randomized controlled phase III clinical trial was designed and registered in the China Clinical Trials Registry (Registration number: ChiCTR-TRC-12002719). Survival data were analyzed in terms of intention-to-treat (ITT) and per-protocol (PP) sets for patients undergoing cisplatin and 5-fluorouracil (PF) (group A), or cisplatin and paclitaxel (TP) (group B).

Results: The incidence risk of grade III-IV leukopenia in group B was higher than in group A (49.2% vs. 25.5%, p = 0.012). The survival rates at 1, 2, 3, and 5 years were 83.8%, 62.6%, 53.1%, and 41.3%, respectively. Consolidation chemotherapy after concurrent chemoradiation therapy had no benefit on median progression-free survival (PFS) (p = 0.95) and overall survival (OS) (p = 0.809). According to the ITT analysis, the median PFS in group A and group B was 28.6 months and 30.3 months (X² = 0.242, p = 0.623), while the median OS was 31.0 months and 50.3 months (X² = 1.25，p = 0.263). For the PP analysis, the median PFS in group A and group B were 28.6 months and 30.3 months (p = 0.584), while the median OS was 31.0 months and 50.3 months (p = 0.259), respectively. Patients receiving consolidation chemotherapy did not show significant OS benefits (46.9 months vs. 38.3 months; X² = 0.059, p = 0.866).

Conclusion: Similar PFS and OS were found between PF and TP regimens with concurrent chemoradiotherapy. Consolidation chemotherapy did not show any significant OS benefits.