Prognostic significance of immunoscore related markers in bladder cancer

Abstract

Background: The significance of total and specific subpopulations of tumor-infiltrating lymphocytes (TILs) in cancer is now well-documented. In the present study, we investigated the relevance of CD3+, CD8 +, CD45RO +, and FOXP3 + TILs to the prognosis and survival of patients with bladder cancer and the disease's clinical-pathological parameters.

Methods: Infiltration of each subset was immunohistochemically evaluated in both stromal and intratumoral regions of tumor tissues from 85 patients with urothelial cell carcinoma of the bladder, with known survival.

Results: Our results indicated that intratumoral CD45RO+ lymphocytes were significantly higher in high-grade tumors than in low-grade ones (P = 0.028). The frequencies of intratumoral CD3+ (P = 0.002), CD8 + (P = 0.008), intratumoral (P = 0.002), and stromal (P = 0.017) CD45RO+ lymphocytes were also higher in patients with muscular invasion than those without invasion. The frequencies of intratumoral CD3+ (P = 0.043), CD8+ (P = 0.003), CD45RO+ (P = 0.023), and total CD45RO+ (P = 0.015), showed variation in patients with different T-stage, as well; mostly increased in T2 versus Ta and T1. Comparing patients in different stages revealed an increase in the frequencies of total CD3+ (P = 0.011), intratumoral CD3+ (P = 0.006), total CD8+ (P = 0.012), intratumoral CD8+ (P = 0.009) and stromal CD8+ (P = 0.034), as well as total and stromal CD45RO+ lymphocytes (P = 0.01 and P = 0.034, respectively) in stage II comparing to stage I, while the frequencies of stromal CD3+ (P = 0.077) and CD8+ (P = 0.053) cells tended to be decreased in stage III compared to stage II.

Conclusions: We collectively observed that the frequency of immune cells, especially CD45RO+, CD3+, and CD8+ lymphocytes, were significantly higher in early-progressed tumors. This observation could be explained by continuous and prolonged stimulation of immune cells with tumor antigens during tumor progression or an increase in the recruiting factors, especially in the early stages, to eliminate tumor cells. However, with tumor progression to the late stages, the inhibitory microenvironment provided by tumor cells suppresses or changes the functionality of the effector and memory immune cells to help tumor growth. However, more functional studies with larger sample sizes are needed to reveal the real status of the immune system in patients with bladder cancer.

Keywords: Bladder cancer; CD3; CD45RO; CD8; FOXP3; TILs.

Fig. 1

Patterns of lymphocytes’ infiltration in bladder tumor tissues. Infiltration of lymphocytes in both stromal (red arrows) and intratumoral (yellow arrows) was investigated (a). Representatives of low (top) and high (bottom) infiltrations of each cell subset are also shown (b). The images were captured at 200 × magnification

Fig. 2

Frequencies of immune cells among clinically relevant parameters of bladder tumors: histological grade (a) and muscle invasion (b). The data are presented as median. *Difference is significant at 0.05 level (2-tailed), **Difference is significant at 0.01 level (2-tailed). IT: intratumural region, ST: tumor stroma

Fig. 3

Death Hazard function of patients (follow-up time based on month) and survival plot based on immune cells groups. Patients without invasion showed better survival than those with invasion to the muscular layer (a). The hazard rate of death was constant overtime for four years but dramatically increased after that (b)