Presence of lymphocytic infiltrate cytotoxic T lymphocyte CD3+, CD8+, and immunoscore as prognostic marker in patients after radical cystectomy

Abstract

Tumor-Infiltrating Lymphocytes (TILs) has been shown to be essential to predict disease outcome in several types of cancers. Moreover, the distribution of cytotoxic T lymphocytes (CD8+) and T cells in general (CD3+) have been used to establish an Immunoscore, as a new cancer prognosticator for survival in colon and lung cancer. In bladder cancer, immune activation has been shown to be associated with genomic subtypes of muscle invasive bladder cancer (MIBC). We sought to evaluate the prognostic impact of these immune cell types in MIBC patients treated with radical cystectomy. For this purpose, cystectomy sections (n = 67) with identifiable invasive margin were selected and stained for CD8+ and CD3+ tumour infiltrating lymphocytes (TILs); both tumor core (CT) and invasive margin (IM) were assessed. Immunoscore was calculated based on previously defined criteria and used to illustrate differences in survival. High density of CD8IM TILs was associated with better disease-free (DFS) (P = 0.01) and overall survival (OS) (P = 0.02) whereas CD3IM TILs were associated with better OS (P = 0.05). Immunoscore was associated with improved DFS (P = 0.02) and OS (P = 0.05). The expression of cytotoxic T cells (CD8+ T cells) in TCGA bladder cancer was also investigated from RNA-Seq profiles of 344 cases. T cell cytotoxicity associated genes (n = 113) were derived from MSig GSEA database. Luminal (n = 121) and basal (n = 68) samples were used to evaluate expression differences. Differential expression (P<0.05) of cytotoxic T cell genes was noted across different molecular subsets of bladder cancer within TCGA analysis. Our data suggests host immune system appears to play a valuable prognostic role in MIBC.

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. High vs. low density and locations of CD8+.

(A) High concentration CD3+ in CT and IM. (B) High concentration CD8+ in CT and IM. (C) Low concentration CD3+ in CT and IM. (D) Low concentration CD8+ in CT and IM.

Fig 2. Kaplan–Meier plots of OS according to CD3+ and CD8+ TILs in the invasion margin (IM).

(A) OS in all patients according to Low CD3+(IM) ≤ 290 (n = 49) vs. High CD3+(IM) > (n = 18). (B) OS in all patients according to Low CD8+(IM) ≤ 70 (n = 17) vs. High CD8+(IM) > 70 (n = 48). P values are from log-rank tests.

Fig 3. Kaplan–Meier plots of DFS according to CD3+ and CD8+ TILs in the invasion margin (IM).

(A) DFS in all patients according to Low CD3+(IM) ≤ 290 (n = 49) vs. High CD3+(IM) > 290 (n = 18). (B) DFS in all patients according to Low CD8+(IM) ≤ 70 (n = 17) vs. High CD8+(IM) > 70 (n = 48). P values are from log-rank tests.

Fig 4. Box plots showing differential expression of CD8A transcripts (p<0.05) in luminal (n = 121) vs basal (n = 68) MIBC tumours.

Fig 5. Heatmap summary showing the significantly differentially expressed T cell cytotoxicity associated genes between TCGA (Blue) clusters I (Luminal n = 121) and (Red) cluster IV (Basal n = 68).

Red indicates low expression and green indicates high expression.

Fig 6. Box plots showing significantly differential CD8+(IM) infiltration among non responders and responders (P = 0.01) to neoadjuvant chemotherapy.