The value of routine endoscopic ultrasound in patients with esophageal cancer undergoing active surveillance after neoadjuvant chemoradiotherapy.

BACKGROUND: Active surveillance for esophageal cancer after neoadjuvant chemoradiotherapy (nCRT) involves repeated diagnostic tests to detect cancer regrowth. In the SANO trial, this included esophagogastroduodenoscopy (EGD) with biopsies, endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) of suspicious lymph nodes, and fluorodeoxyglucose positron emission tomography with computed tomography (PET-CT). The value of routine EUS in this setting remains largely unknown. This study aimed to assess the diagnostic yield of EUS over PET-CT.

METHODS: A retrospective analysis of patients with esophageal cancer who underwent nCRT followed by clinical response evaluations with EGD, EUS, and PET-CT was performed. Initial response assessment was performed within 3 months post-nCRT. Patients without tumor regrowth underwent active surveillance with repeated diagnostic testing. The primary outcome was the rate of EUS-detected lymph node metastases missed by PET-CT, after excluding cases with positive EGD findings or distant metastases.

RESULTS: 327 patients underwent both PET-CT and EUS post-nCRT, accounting for 1006 combined procedures: 327 at initial response assessment; 679 during active surveillance (6-60 months post-nCRT) in 121 patients. Positive lymph nodes were detected by EUS in 3.7% (12/327) of initial response assessments, with 2.1% (7/327) unidentified by PET-CT. During surveillance, this dropped to 0.9% of assessments (6/679), with 0.1% (1/679) missed by PET-CT.

CONCLUSIONS: EUS with FNA adds most value at 3 months post-nCRT, when the likelihood of detecting recurrence is highest. Beyond 3 months, its added value is limited (0.1% with negative PET-CT). Restricting the use of EUS to PET-suspicious nodes could omit 98% of EUS procedures.