Poster session 8: Bladder cancer, Urinary diversion and Pediatric urology| Volume 8, ISSUE 8, P698, September 2009

C124 NK cell immunohistochemistry – a new prognostic marker of bladder cancer recurrence?

      Introduction and Objectives

      The aim of the present study was to evaulate the prognostic value of the local NK cell count in patients with recurrent non-muscle invasive bladder cancer.

      Material and Methods

      The archival paraffin-embedded primary tumor specimens were derived from retrospectively selected patients who were treated between 1996 and 2001 for bladder cancer. Primary tumors were staged according to AJCC-TNM classification from 2002, and graded according to the World Health Organization classification system from 1973. Patients with non-muscle invasive bladder cancer were enrolled in this study, those with carcinoma in situ and T1GIII were excluded because of possible associated local inflammatory reaction and malignant potential. Study group consisted of 46 patients who developed recurrent disease during first two postoperative year. Control group consisted of 27 patients who did not develop recurrent disease during first two postoperative year. Specimens were assessed immunohistochemically with standard “ABC”technic (monoclonal antibodies CD56 NCL-LCD56–1B6, “NovoCastra Laboratories”). The frequency of NK cells was expressed as total number, estimated for each tumor by counting the positive NK cells in 10 high-power representative fields (200×). Statistical analysis was done using Kruskal-Wallis test.


      Patients with recurrent non-muscle invasive bladder cancer in general have significantly higher (p < 0.05) values of stromal NK cell count than the control group. Analysis of the patients with single tumors showed that patients in study group have significantly higher (p < 0.05) NK cell count than those of control group and we estimated a clear cutoff value in NK cell count (42 cells) between these groups of patients (graph 1). Patients with smaller tumors (<3 cm) show statistically significant difference (p < 0.05) in NK cell count between study and control group (graph 2). There also exists statistically significant difference (p ≪ 0.05) in stromal NK cell count in patients with clinical stage Ta.
      Figure thumbnail pl1
      Graph 1.NK cell count in single-tumor patients.
      Figure thumbnail pl2
      Graph 2.NK cell count in relation to tumor diameter.


      Our results confirm an association of the bladder wall NK cell count in bladder cancer patients with the natural history of disease. Further well-performed, reproducible, large, prospective investigation stratified by clinical parameters such as tumor number and diameter is needed to display true value of this marker in the clinical work-up of bladder cancer patients.