65 Background: Older age and female gender have been associated with worse outcomes in patients with muscle invasive bladder cancer undergoing radical cystectomy. Reduced immune response has been implicated in disease metastasis and worse survival. The objective of our study was to determine the expression patterns of various cellular proteins active in immune pathways in bladder cancer patients, and assess the correlation between age, gender, and expression of these immune markers. Methods: Tissue samples were obtained from equally distributed male/female patients with/without lymph node metastasis on final pathology after undergoing radical cystectomy for transitional cell carcinoma (TCC) of the bladder from 2009-2011 (n = 50). Immunohistochemistry (IHC) for CD3, CD4, CD8, LAG3, CD56, TIM3, PD-1 and PD-L1 were performed and scored by a single pathologist (scoring was on 0 to 100% scale). Statistical analyses investigated association between age, gender, lymph node metastasis, and IHC results. Results: Mean age at surgery was 67 yrs (range 50 to 78 yrs); all patients were Caucasians. Statistical analyses showed no association between patients' age, gender, and the expression of any of the immune markers (p > 0.05). Similarly, the staining scores for the immune markers were not noted to be correlated with LN metastasis. Correlation between stains showed a negative correlation between CD56 and PD-L1 (-0.286, p = 0.047) and between PD-1 and PD-L1 (-0.381, p = 0.007). Conclusions: Although age and female gender have been associated with worse outcomes in bladder cancer, this association may be independent of the immune pathways active in the disease. Increased expression of PD-L1 is associated significantly with suppression of anti-tumor natural killer cells in the transitional cell carcinoma of the bladder.
