Pre-treatment maximal oesophageal wall thickness is independently associated with response to chemoradiotherapy in patients with T3-4 oesophageal squamous cell carcinoma

Combined chemoradiotherapy with or without surgery is frequently performed as a curative treatment in patients with T3-4 locally advanced oesophageal squamous cell carcinoma. Computed tomography (CT) is frequently performed before and after chemoradiotherapy. The aim of this study is to evaluate the utility of the oesophageal wall thickness on CT scans to predict the response to chemoradiotherapy and the treatment outcome in patients with T3-4 locally advanced oesophageal squamous cell carcinoma. Ninety-six patients with T3-4 locally advanced oesophageal squamous cell carcinoma, who were treated with neoadjuvant chemoradiotherapy followed by surgery between 1998 and 2008 at the Kaohsiung Chang Gung Memorial Hospital, were retrospectively reviewed. CT scans before and after chemoradiotherapy were available for 93 patients. Of these 93 patients, 24% (22 of 93) achieved a pathologically complete response (pCR). The measurement of the maximal dimension of the oesophageal wall thickness on CT scans before (pre) and after (post) chemoradiotherapy was performed retrospectively, and correlated with the response to chemoradiotherapy and patients' outcome. The percentage decrease of maximal oesophageal wall thickness after chemoradiotherapy was determined by the formula: [(pre -post)/pre] x 100. Pre- and post-chemoradiotherapy maximal oesophageal wall thicknesses were significantly correlated with pCR, but the percent decrease of oesophageal wall thickness after chemoradiothrapy was not. Logistic models showed that pre-chemoradiotherapy maximal oesophageal wall thickness >= 20 mm was independently associated with response to chemoradiotherapy. For patients with pre-chemoradiotherapy maximal oesophageal wall thickness >= 20 mm, 91% did not achieve pCR after chemoradiotherapy. Univariate analyses demonstrated that a pre-chemoradiotherapy maximal oesophageal wall thickness >= 20 mm, T4 disease and positive regional lymph nodes (N stage) were predictive of inferior disease-free survival. In a multivariate comparison, pre-chemoradiotherapy maximal oesophageal wall thickness >= 20 mm represented an independent adverse prognosticator for disease-specific survival and disease-free survival. Most of the T3-4 locally advanced oesophageal squamous cell carcinoma patients with pre-treatment maximal oesophageal wall thickness >= 20 mm did not achieve pCR after chemoradiotherapy. Thus, oesophgectomy may be considered in advance in this group of patients. Pre-treatment maximal oesophageal wall thickness is of independent prognostic value in patients with T3-4 locally advanced oesophageal squamous cell carcinoma who receive neoadjuvant chemotheradiotherapy.