Myeloid-Derived Suppressor Cells in Nonmetastatic Urothelial Carcinoma of Bladder Is Associated With Pathologic Complete Response and Overall Survival.

BACKGROUND: Myeloid-derived suppressor cells (MDSC) have immunosuppressive activity and enhance tumor progression. We hypothesized that lower blood MDSC would correlate with pathologic complete response and better outcomes in nonmetastatic urothelial carcinoma (UC). PATIENTS AND METHODS: Before cystectomy, blood MDSC were measured in whole blood (WB) and peripheral blood mononuclear cells using flow cytometry. MDSC were defined as CD33+/HLA-DR-. MDSC subtypes were polymorphonuclear MDSC (CD15+/CD14-), monocytic (M)-MDSC (CD15-/CD14+), and uncommitted (UnC) MDSC (CD15-/CD14-). The Wilcoxon rank sum test was used to compare MDSC between pathologic complete response groups. The optimal cutoff points for MDSC were identified using recursive partitioning analysis with cross-validation. The Cox proportional hazard model was used to associate MDSC and other clinical factors with recurrence-free survival and overall survival (OS). RESULTS: Overall, 109 patients were included: 86% men with median (range) age of 67 (30-88) years, 76% with pure UC, 29% intravesical therapy, and 41% neoadjuvant chemotherapy. Twenty-one patients (19%) had pT0N0 and 23 (24%) < pT2N0. Median (range) follow-up time was 17.4 (0.4-42.4) months. Total MDSC and polymorphonuclear MDSC percentage in peripheral blood mononuclear cells was significantly lower in patients with pT0N0 disease (P = .03). One- and 2-year OS rates were 94% (95% confidence interval [CI], 90-99) and 83% (95% CI, 75-93), respectively. In the multivariate Cox model after adjusting for age and gender, patients with higher WB M-MDSC and UnC-MDSC had shorter OS (optimal cutoff points by recursive partitioning analysis, hazard ratio = 7.5 [95% CI, 2.5-22.8], P = .0004; hazard ratio = 3.4 [95% CI, 1.0-11.0], P = .046, respectively). CONCLUSION: In patients with nonmetastatic UC of bladder, higher WB M-MDSC and UnC-MDSC before cystectomy had negative prognostic value. Prospective validation is warranted.

Blood Myeloid-Derived Suppressor Cells Correlate with Neutrophil-to-Lymphocyte Ratio and Overall Survival in Metastatic Urothelial Carcinoma.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) were linked to pathologic stage in bladder urothelial carcinoma (UC). Neutrophil lymphocyte ratio (NLR) is an inflammatory biomarker with a prognostic role in metastatic (m)UC. OBJECTIVE: We hypothesized that MDSC levels correlate with NLR and overall survival (OS) in mUC. PATIENTS AND METHODS: MDSCs were measured in blood samples from patients with mUC in fresh unfractionated whole blood (WB) and peripheral blood mononuclear cells (PBMC) by flow cytometry and defined as LinloCD33+/HLADR- (Total MDSC). MDSC subsets were defined as polymorphonuclear (PMN-MDSC: CD15+/CD14-), monocytic (M-MDSC: CD15-/CD14+), and uncommitted (UNC-MDSC: CD15-/CD14-). MDSC populations were presented as a percentage of live nucleated blood cells. Spearman's rank correlation assessed correlations between MDSC and NLR. Kaplan-Meier curves and log-rank test estimated OS from the time of MDSC collection to last follow-up or date of death. RESULTS: Of the 76 patients, 78% were men and 43% were never smokers with a median age of 69 years (range 31-83); 72% had pure UC and 76% had lower tract UC. Prior therapies included intravesical therapy (22%), neoadjuvant chemotherapy (30%), cystectomy or nephroureterectomy (55%). Median follow-up for all patients was 12 months (0.6-36.5). PMN-MDSC was the predominant subset in WB and PBMC. There was significant correlation between individual MDSC subsets in WB and PBMC (p ≤ 0.001). Both WB UNC-MDSC/PMN-MDSC ratios (rho = - 0.27, p = 0.03) and PBMC UNC-MDSC/PMN-MDSC (rho = - 0.28, p = 0.02) were negatively correlated with NLR. Median OS was 17.7 months (95% CI: 11.0-NE). Overall 1-year and 3-year survival rates were 0.60 (95% CI 0.49-0.73) and 0.15 (95% CI 0.03-0.67), respectively. Higher WB UNC-MDSC levels (HR 3.78, p = 0.0022) and higher NLR (HR 2.6, p = 0.0179) were associated with shorter OS. CONCLUSIONS: Specific MDSC subsets correlate with NLR. Higher WB UNC-MDSC levels and higher NLR were negative prognostic factors. Given the feasibility of serial blood draws, dynamic assessment of MDSC over time and further validation with longer follow-up are warranted.