Prognostic significance of nestin expression in PT1 high-grade bladder urothelial carcinoma patients treated with BCG

PROGNOSTIC SIGNIFICANCE OF NESTIN EXPRESSION IN PT1 HIGH-GRADE BLADDER UROTHELIAL CARCINOMA PATIENTS TREATED WITH BCG INTRODUCTION : Nestin is a class VI intermediate filament protein expressed in stem/progenitor cells during the development of the central nervous system. Nestin is detected in various types of tumors and is involved in malignant processes. We wanted to show the effect of immunohistochemically nestin expression for predicting Bacille Calmette Guarin (BCG) response in T1 high grade bladder cancers. MATERIAL AND METHODS We retrospectively reviewed 1780 bladder cancer patients who followed up between the years of 1990-2009 in our clinic. We choosed the 63 T1 high grade bladder cancer patients treated with BCG. Sections from the paraffin blocks of the most representative tumor tissues were taken and re-graded with 2004 classification of World Health Organization. Staining results evaluated by image analysis program. The expression was scored semiquantitatively as 0: no cells stained, 1: between 0 and 10% stained positive, 2: between 10 and 50% stained positive, 3: if more than 50% stained positive. In our study the staining pattern of 3 was evaluated as nestin positive; the staining pattern of 0,1 and 2 were evaluated as nestin negative. These two groups were compared in terms of recurrence and progression. RESULTS: Among the 63 patients were 52 (82.5%) men and 11 women (17.5%). The overall median duration of follow-up was 25 (3-191) months. The median follow up time for recurrence and progression was 7 (2-41) and 4 (3-33) months. 29 (%46) patients had recurrence and 8 (%12,6) patients had progression. Table 1 shows demographic datas of patients and tumor characteristics. Nestin was stained as nestin positive in 33 (%52,4) patients and 30 patients were evaluated as nestin negative. When we compared recurrence (+) and recurrence (-) patients, there were no statistical differences with concomitant carsinoma in situ (CIS), tumor size, number of tumors, gender and age of patients. Nestin positive patients showed more recurrence (p=0,014) (table 2). We found that nestin expression has no role in predicting progression (p=0.710) (table 3). CONCLUSION Nestin expression, which seems effective in predicting recurrence, appear to have a potential role in the early stages of urothelial carcinoma tumorigenesis. On the other hand, nestin expression does not seem to predict progression which is the late stage of tumorigenesis. Development of progression in these patients may be associated with angiogenesis related factors other than nestin. In conclusion, we suggest that patients with high grade bladder cancer and positive nestin expression may need close follow-up, might be offered radical treatments earlier and rescued from unnecessary BCG treatment cycles. However, further comprehensive studies including larger patient cohorts are needed.