The Prognostic and Potentially Predictive Value of the Laurén Classification in Oesophageal Adenocarcinoma

Aim: To investigate the histological subtypes of oesophageal adenocarcinoma according to the Laurén classification (intestinal/diffuse/mixed) in relation to tumour response to neoadjuvant treatment, and in relation to patients' survival after potentially curative treatment.

Methods: Data were collected from all oesophageal adenocarcinoma patients who underwent potentially curative treatment in our institute between 1998 and 2014. Treatment consisted of neoadjuvant chemoradiotherapy (36-50 Gy) followed by an oesophagectomy or definitive chemoradiotherapy (50-50.4 Gy). Clinical data were collected from patient records. All endoscopic biopsies and surgical resection specimens were reassessed to determine the histological subtype (intestinal, diffuse or mixed) and the Mandard tumour regression grade (TRG). The impact of the histological subtypes on survival was determined using a Cox model.

Results: Median follow-up was 68 months. Diffuse and mixed type cancers accounted for 25% of oesophageal adenocarcinomas. Median overall survival differed significantly between patients with intestinal (n = 121, 39 months), diffuse (n = 28, 18 months) or mixed type (n = 11, 25 months) carcinomas (log rank, p = 0.023). In multivariable analysis, the diffuse type was associated with shorter survival (diffuse versus intestinal: hazard ratios 2.06, p = 0.006). A pathologically (near) complete response (TRG 1 or 2) was seen less frequently in diffuse type than in intestinal type carcinomas (24% versus 60%; p = 0.015).

Conclusions: Patients with diffuse type oesophageal adenocarcinomas had a significantly worse prognosis than those with intestinal type carcinomas. Intestinal type carcinomas showed a better response to neoadjuvant chemoradiotherapy than diffuse type carcinomas. These differences call for the exploration of differentiated approaches in the potentially curative treatment of oesophageal adenocarcinomas.