Summary Recently, nm23-H1, an anti-metastasis gene, has been reported to correlate with sensitivity to chemotherapeutic agents including cisplatin in human breast and ovarian carcinoma cells. The aim of this study was to evaluate a role for nm23-H1 in responsiveness to cisplatin-based chemotherapy in patients with oesophageal squamous cell carcinoma (OSCC). The expression of nm23-H1 protein was examined immunohistochemically in 32 eligible patients with OSCC who underwent adjuvant chemotherapy with cisplatin, etoposide, and 5-fluorouracil after tumour resection. Fifteen (46.9%) of 32 patients were positive for nm23-H1 staining and 17 (53.1%) were negative. Both disease-free survival and overall survival rates of nm23-H1-negative patients were significantly shorter than in nm23-H1-positive patients (P < 0.01 for both). There was no significant difference in clinicopathologic characteristics between nm23-H1-positive and nm23-H1-negative groups. Multivariate analysis also showed that nm23-H1 expression was the most significant factor for overall survival of OSCC patients included in this study (P = 0.0007). To further study the role of nm23-H1, a human OSCC cell line (YES-2) was transfected with a plasmid containing a fragment of the nm23-H1 cDNA in an antisense orientation. Reduced expression of nm23-H1 protein in the antisensetransfected (AS) clones was found by Western blot analysis as compared to wild-type YES-2 and YES-2/Neo (clone transfected with the neomycin resistance gene alone). MTT (3-(4,5-dimethyl-2-thiazol)-2,5-diphenyl-2H tetrazolium bromide) assay showed that reduced expression of the nm23-H1 protein in AS clones was consistent with the degree of increased resistance to cisplatin but not etoposide or 5-fluorouracil. These data support the conclusion that reduced expression of nm23-H1 may be associated with resistance to cisplatin, suggesting the value of nm23-H1 expression as a prognostic marker for OSCC patients who are to undergo cisplatin-based chemotherapy. © 1999 Cancer Research Campaign Keywords: nm23; cisplatin; chemotherapy; prognosis; oesophageal squamous cell carcinoma
469British Journal of Cancer (1999) 81(3), 469-475 © 1999 Cancer Research Campaign Article no. bjoc.1999 Received 17 September 1998 Revised 1 February 1999 Accepted 21 April 1999Correspondence to: N Iizuka, Department of Bioregulatory Function, Yamaguchi University School of Medicine, Ube, Yamaguchi 755-8505, Japan follow-up periods respectively. One patient was excluded because of loss to follow-up. Therefore, the present study was undertaken in 32 patients retrospectively selected. One course of cisplatinbased chemotherapy consisted of etoposide 120 mg m -2 per day and 5-fluorouracil (5-FU) 500 mg m -2 per day by intravenous (i.v.) continuous infusion on days 3-5, and cisplatin 50 mg m -2 per day by i.v. bolus infusion on days 1 and 8. Seven (21.9%) of 32 patients underwent only 1 course of this regimen because of sideeffects, while 25 patients (78.1%) underwent two course of this regimen following resection. All patient...