OEO2 is a randomized, controlled trial of preoperative chemotherapy in patients undergoing radical surgery for esophageal cancer. Random assignment was to surgery alone (S) or to two cycles of combination cisplatin and fluorouracil before surgery (CS). Initial results reported in 2002 demonstrated an advantage for both disease-free and overall survival in the CS group. The analysis has now been updated after a median follow-up of 6 years.

OEO2 recruited 802 patients, 400 on CS and 402 on S. The nature of the first recurrence event and cause of death are detailed. Survival has been determined from Kaplan-Meier curves and treatment comparisons made with the log-rank test. Survival by extent of resection is presented.

There were 655 deaths, 335 for S and 320 for CS. The survival benefit has been maintained with a hazard ratio (HR) of 0.84 (95% CI, 0.72 to 0.98; P = .03) which in absolute terms is a 5-year survival of 23.0% for CS compared with 17.1% for S. The treatment effect is consistent in both adenocarcinoma and squamous cell carcinoma. The first disease-free survival event was macroscopic residual disease from incomplete resection (R2) or no resection in 26.4% of the S group versus 14.3% of the CS P < .001. Three-year survival by type of resection was R0 42.4%, R1 was 18.0%, and R2 was 8.6%.

Long-term follow-up confirms that preoperative chemotherapy improves survival in operable esophageal cancer and should be considered as a standard of care.