Impact of current “insufficient” clinical nodal staging on treatment decisions and response to neoadjuvant chemoradiotherapy in esophageal cancer patients.

Abstract

111 Background: Although essential in treatment decision making, clinical nodal (cN) staging in esophageal cancer (EC) remains difficult. We assessed the rate of nodal up- and downstaging and its prognostic value on 5-year disease-free survival (DFS) in EC patients treated with surgery-alone or with neoadjuvant chemoradiotherapy (nCRT). Methods: For this retrospective study, we included 395 EC patients who underwent a curative esophagectomy with or without nCRT between 2000 and 2015. The surgery-alone and nCRT group were matched on clinical T-stage (cT), cN-stage, and histopathological type using propensity score matching ( n=270). Staging consisted of PET with CT, or PET/CT, and endoscopic ultrasonography (n = 235). We compared cN and pathological N-stage (pN) and scored correct, down- and upstaging. The prognostic value of nodal up- and downstaging and localization of node metastases on 5-year DFS were assessed with multivariate Cox regression analysis (factors with a P-value <0.1 on univariate analysis). Results: Nodal upstaging (43.0% vs. 16.3%), correct staging (31.9% vs. 28.1%) and downstaging (25.2% vs. 55.6%) differed between the surgery-alone and nCRT group ( P<0.001). Nodal upstaging was commonly present in adenocarcinoma and cT3-4a tumors. Independent prognostic factors for DFS were pN ( P=0.002) and lymph-angioinvasion ( P=0.016) in the surgery and cN metastasis under the diaphragm ( P=0.012) and lymph node ratio ( P=0.034) in the nCRT group. Conclusions: In esophageal cancer, clinical lymph node staging is still insufficient with >25% nodal downstaging. This inaccuracy might impede assessment of true nodal response to nCRT, affording dubious decisions for a ‘wait-and-see’ strategy.