Expression of CD44 variants and prognosis in oesophageal squamous cell carcinoma

Background-The CD44 variant (CD44v) isoforms have been noted as markers for tumour metastasis and prognosis in several adenocarcinomas. Aims-To investigate whether CD34v, especially the CD44v2 (v2) isoform, may be a useful prognostic factor for patients with oesophageal squamous cell c arcinoma, using a recently developed monoclonal antibody against a v2 epito pe. Patients-233 patients (211 men and 22 women; mean age 61.9 years), with oes ophageal squamous cell carcinomas curatively removed without additional tre atment between 1987 and 1996 at the National Cancer Center Hospital, were a nalysed for CD44v expression. Methods-The expression of CD44v was evaluated immunohistochemically using m onoclonal antibodies against epitopes of the standard and variant protein, in paraffin embedded oesophageal squamous cell carcinoma tissue from 233 pa tients who had undergone cervical, mediastinal, ana abdominal lymphadenecto my (three field dissection) for oesophagectomy. The data were evaluated for any correlation with clinicopathological indices or prognosis. Results-Although total CD-14 and CD44v6 (v6) were respectively observed in 99% and 97% of the canter specimens, the expression of v2 was only 30%. Pat ients whose tumours were v2 positive had a significantly better prognosis t han those whose tumours were v2 negative (p = 0.031). Furthermore, in patie nts without lymph node metastasis, v2 positivity alone was a significant in dependent factor of prognosis (relative risk of death associated with v2 ne gativity, 4.7; p = 0.037) in multivariate analysis. Conclusions-These results indicate that v2 is a useful marker for clinical prognosis in patients with oesophageal squamous cell carcinoma. Particularl y in patients without lymph node metastasis, v2 status may thus have implic ations for the use of adjuvant chemotherapy and/or radiotherapy in patients with oesophageal cancer at an early stage.