Human leukocyte antigen class I down-regulation in muscle-invasive bladder cancer: Its association with clinical characteristics and survival after cystectomy

Using a novel monoclonal anti-pan human leukocyte antigen (HLA) class I heavy chain antibody (EMR 8-5) reacting with paraffin-embedded sections, we examined the prognostic significance of HLA class I molecules in muscle-invasive bladder cancer patients who underwent radical cystectomy. Immunohistochemical staining for HLA class I molecules with monoclonal antibody EMR 8-5 was performed on specimens from 65 clinically muscle-invasive bladder cancer patients who underwent radical cystectomy and pelvic lymph node dissection without neoadjuvant chemotherapy. We analyzed the clinicopathological and prognostic significance of HLA class I expression. Immunohistochemical analysis revealed HLA class I down-regulation in 22 (33.8%) invasive bladder cancers. This down-regulation had no correlation with clinicopathological parameters such as pathologic stage, nodal status, and grade. The recurrence-free survival of patients with HLA class I-positive tumors was significantly better than that of those with down-regulation (log rank, P = 0.0337). Multivariate analysis revealed that HLA class I expression was a significant factor influencing the recurrence-free survival of bladder cancer patients after cystectomy (P = 0.0155). Our data demonstrate that HLA class I down-regulation in tumor cells was clearly observed in about one-third of the patients. HLA class I expression could be a prognostic marker for muscle-invasive bladder cancer patients after cystectomy. (Cancer Sci 2009; 100: 2331-2334).