PD-L1 expression in tumor cells and the immunologic milieu of bladder carcinomas: a pathologic review of 165 cases.

Programmed death ligand 1 (PD-L1) is a transmembrane protein that plays a major role in immune suppression. Its interaction with the receptor PD-1 results in downregulation of antitumoral immunity. Humanized monoclonal antibodies that interrupt the PD-L1/PD-1 interaction have shown therapeutic efficacy in patients with advanced urothelial cancer. However, immunohistochemical staining of PD-L1 in bladder tumors and its relationship to tumor histologic type, grade, and overall survival has been incompletely analyzed. Slides from 165 cystectomy specimens were reviewed for tumor type, grade of urothelial carcinoma, pathologic stage, and overall survival. A tissue microarray (TMA) using four 0.6 mm cores from each case was constructed. Immunohistochemistry was performed on the TMA using a variety of new PD-L1 antibodies and platforms now widely available. For each case, the percent of tumor cells positive for PD-L1 and the percent of positive immune cells were scored. The overall number of bladder cancers positive for PD-L1 depended on the antibody/platform combination used and the threshold for considering a tumor "PD-L1-positive." Squamous cell carcinomas (SCCs) of the bladder demonstrated PD-L1 positivity more frequently than urothelial cell carcinomas (UCCs). High-grade UCCs were positive for PD-L1 on tumor cells more frequently than low-grade UCCs. There was no difference in survival between PD-L1-positive and PD-L1-negative bladder cancers in our study. Further studies should consider examining the predictive significance of PD-L1 IHC in bladder cancers.

Davick JJ ，Frierson HF ，Smolkin M ，Gru AA ... -  《-》

Differential Expression of PD-L1 in High Grade T1 vs Muscle Invasive Bladder Carcinoma and its Prognostic Implications.

PD-L1 is expressed on tumor cells and tumor immune cell infiltrates. In metastatic bladder cancer increased tumor immune cell infiltrate PD-L1 positivity correlated with better overall survival. However, to our knowledge in high grade T1 bladder tumors positivity on tumor cells and tumor immune cell infiltrates, and correlation with outcomes or pathological features remain unknown. Formalin fixed, paraffin embedded tumor samples from 140 patients with clinically annotated, high grade T1 bladder tumors were retrieved. All patients were initially diagnosed with high grade T1 bladder tumors by transurethral resection, subsequently received bacillus Calmette-Guérin and had a median followup of 7.4 years. PD-L1 positivity on initial transurethral resection was evaluated by immunohistochemistry using a mouse monoclonal antiPD-L1 antibody (405.9A11). Tumor cell PD-L1 positivity was defined as staining of 5% of the tumor cell membrane. Tumor immune cell infiltrate PD-L1 positivity was scored based on the extent of infiltrate and the percent of positive cells. The Fisher exact test was used to assess associations of PD-L1 positivity with disease outcomes, carcinoma in situ presence and the difference between high grade T1 bladder tumors and muscle invasive bladder cancer. Among 140 patients with high grade T1 bladder tumors tumor cells and tumor immune cell infiltrate PD-L1 positivity was seen in 6 (4%) and 48 (34.3%), respectively. In a subset of 106 patients with adequate followup PD-L1 positivity did not correlate with disease outcomes on tumor cells (p = 0.3) or on tumor immune cell infiltrates (p = 0.47). PD-L1 positivity also did not correlate with the presence of carcinoma in situ. Tumor cell PD-L1 positivity was significantly less in high grade T1 bladder tumors than in muscle invasive bladder cancer (p <0.001). PD-L1 is widely expressed on tumor immune cell infiltrates but not on tumor cells in high grade T1 bladder tumors. We did not find a correlation between PD-L1 positivity and outcomes or carcinoma in situ presence. Tumor cell PD-L1 positivity is significantly lower in high grade T1 bladder tumors than in muscle invasive bladder cancer.

Wankowicz SAM ，Werner L ，Orsola A ，Novak J ，Bowden M ，Choueiri TK ，de Torres I ，Morote J ，Freeman GJ ，Signoretti S ，Bellmunt J ... -  《-》

Expression and prognostic utility of PD-L1 in patients with squamous cell carcinoma of the bladder.

Checkpoint inhibitors are approved for the treatment of urothelial bladder cancer. However, there have been no reports on the prognostic value of programmed-death receptor ligand 1 (PD-L1) expression in squamous cell carcinoma (SCC) of the bladder. We assessed the relationship between PD-L1 expression, clinicopathological features, and oncologic outcomes in bladder SCC. Immunohistochemistry of PD-L1 was performed on 151 radical cystectomy specimens with pure SCC treated in Mansoura, Egypt from 1997 to 2004. Median patient age was 52 years (range: 36-74 years) and median length of follow up was 63 months (range: 1-100 months). Schistosomiasis was present in 81% of the specimens and 93% had muscle-invasive disease on pathologic staging. PD-L1 expression was negative in 50 (33%) of the specimens. Negative PD-L1 expression was associated with higher pathologic tumor stage (P = 0.04), higher grade lesions (P = 0.01), and the presence of lymphovascular invasion (P < 0.01). Kaplan-Meier analyses showed that negative PD-L1 expression is associated with worse recurrence-free (P = 0.01) and worse cancer-specific survival (P = 0.01). Multivariable Cox regression analyses showed negative PD-L1 expression was an independent predictor of disease recurrence (hazards ratio 2.05, 95% confidence interval 1.06-3.96, P = 0.03) and cancer-specific mortality (hazards ratio 2.89, 95% confidence interval 1.22-6.82, P = 0.02). Negative PD-L1 expression is associated with higher pathologic tumor stage, higher grade lesions, presence of lymphovascular invasion, and worse oncologic outcomes after radical cystectomy for SCC. These findings support the need for the inclusion of patients with bladder SCC into immunotherapy clinical trials.

Owyong M ，Lotan Y ，Kapur P ，Panwar V ，McKenzie T ，Lee TK ，Zi X ，Martin JW ，Mosbah A ，Abol-Enein H ，Ghoneim M ，Youssef RF ... -  《-》

PD-L1 Immunohistochemistry Assay Concordance in Urothelial Carcinoma of the Bladder and Hypopharyngeal Squamous Cell Carcinoma.

Hodgson A ，Slodkowska E ，Jungbluth A ，Liu SK ，Vesprini D ，Enepekides D ，Higgins K ，Katabi N ，Xu B ，Downes MR ... -  《-》

High PD-L1 expression on immune cells, but not on tumor cells, is a favorable prognostic factor in urothelial carcinoma.

Zhong Q ，Shou J ，Ying J ，Ling Y ，Yu Y ，Shen Z ，Zhang Y ，Li N ，Shi Y ，Zhou A ... -  《-》