Multicenter trials in esophagogastric cancer have not improved overall survival, raising urgent questions about trial design.

• 27 trials were analyzed; only 10 aimed for survival superiority, none achieved significant benefits.
• Common issues included limited surgeon credentialing and poor adherence monitoring.
• Trials often lacked adequate power and internal piloting, with a 10% nonadherence potentially halving statistical power.

Surgeons should advocate for more rigorous quality assurance in trial design to enhance outcome validity.