Endoscopic ultrasound in staging esophageal cancer after neoadjuvant chemotherapy – results of a multicenter cohort analysis

Purpose: Endoscopic ultrasound (EUS) is considered a gold standard in the initial staging of esophageal cancer. There is an ongoing debate whether EUS is useful for tumor staging after neoadjuvant chemotherapy (NAC).

Material and methods: Ninety-five patients with esophageal cancer were retrospectively analyzed. In 45 patients EUS was performed prior to and after NAC while 50 patients had no induction therapy. Histological correlation through surgery was available. uT/uN classifications were compared to pT/pN stages. Statistical analysis included calculation of sensitivity, specificity and accuracy rates. Agreement between endosonography and T staging was assessed with Cohen's kappa statistics

Results: Those patients with prior NAC, overall accuracy of yuT and yuN classification was 29% and 62%, respectively. Sensitivity, specificity and accuracy rates for local tumor extension after NAC were as follows (%): T1: –/97/84; T2: 13/76/53; T3:86/29/46; T4:20/100/91; T1/2: 27/83/56; T3/4: 89/31/56. Cohen's kappa indicated poor agreement (kappa = 0.129) between yuT classification and ypT stage. Relating to positive lymph node detection sensitivity and specificity were 100% and 6%, respectively (kappa = 0.06). T stage was overstaged in 23 (51%) and understaged in 7 (16%) of the patients.

Conclusion: EUS is an unreliable tool for staging esophageal cancer after NAC. Overstaging of the T stage is common after NAC