Table 2 Summary of findings of study included in review

Xie et al.

Examine the relationship between risk signature and clinical parameters

Progression-free survival (PFS)

Strong positive correlation of risk scores with CD8+ T cells and regulatory T cells (Tregs) infiltration

Strong negative correlation was observed with follicular helper T cells and resting memory CD4+ T cells

Glud et al.

Investigate the prostate-specific membrane antigen expression and CD8+ T cells infiltration of PCa tumor

Recurrence-free survival (RFS)

CD8+ T cell infiltrating score was elevated in metastatic prostate cancer tissue as compared with normal, adjacent normal, localized prostate cancer tissues (p < 0.05)

Fu et al.

To identify immune genes that exhibit a high correlation with prostate cancer recurrence

Cancer recurrence

Reduced infiltration by neutrophils, activated mast cells, CD4 memory-activated T cells and CD4 memory resting T cells results in increased rate of recurrence

Increased influx of macrophages M2 and regulatory T cells (Tregs) increased risk of recurrence and a reduced rate of DFS (p < 0.01)

The group classified as low-risk demonstrated elevated levels of immune cell infiltration, including CD8+ T cells, CD4+ T cells, macrophages, dendritic cells and neutrophils

Zhou et al.

The study examined the infiltration of CD8+ and Foxp3+ lymphocytes in 239 prostate cancer (PCa) tissues. It aimed to establish a new immune classification by considering the expression of B7-H3 and HHLA2, as well as the density of tumor-infiltrating T cells

Overall survival (OS) and cancer-specific survival (CSS)

The immune type IV, characterized by a high B7-H3 score and low levels of CD8+ tumor-infiltrating lymphocytes (TILs), exhibited a more significant correlation with poor overall survival (OS) and cancer-specific survival (CSS)

On the other hand, the immune type I, characterized by a low B7-H3 score and high levels of CD8+ TILs, showed a significant correlation with improved overall survival (OS) and cancer-specific survival (CSS)

Ma et al.

Low versus high-level infiltration phenotype on PCa prognosis

Disease-free survival

The high-level cluster was associated with a shorter DFS when compared to the low-level cluster (p = 0.020). Myeloid-derived suppressor cells (MDSCs), Th1 cells, T helper cells, Tgd and plasmacytoid dendritic cells (pDC) demonstrated the highest prognostic value. Furthermore, the high-level cluster exhibited a higher abundance of these cells

Yang et al.

Significance of CD8+ tumor Infiltration lymphocyte (TIL) in radical prostatectomy

Overall survival

High CD8+ tumor-infiltrating lymphocyte (TIL) density is linked to improvement in a 5-year OS rates (98% vs. 91%; p = 0.01) and PCa-specific survival rates (99% vs. 95%; p = 0.04) compared to the low CD8+ TIL density group

Additionally, the high CD8+ TIL density group demonstrated an increased 5-year biochemical recurrence-free survival (BRFS) and metastasis-free survival (MFS) rates

Liu et al.

Investigate the relationships between gene expression patterns and immune cell infiltration in prostate cancer

Biochemical recurrence

In the high-risk group, there were higher levels of infiltration observed for memory B cells, regulatory T cells, M2 macrophages and dendritic cells. On the other hand, in the low-score group, higher levels of infiltration were observed for activated mast cells, monocytes and CD8+ T cells

Sun et al.

Investigate the relationship between the tumor microenvironment and prostate cancer prognosis

Overall survival

Prostate cancer (PCa) tumors exhibiting higher immune scores demonstrate increased infiltration of macrophages, B cells, T cells and monocytes

The group with lower immune scores exhibited a significantly decreased survival rate

Wu et al.

Patterns of immune cells infiltration and potential as prognostic biomarkers in the microenvironment of prostate cancer (PCa)

Overall survival

An increased presence of M1 macrophages and neutrophils in the tumor microenvironment was associated with a poor prognosis

There was a consistent trend of reduced infiltration observed for T and mast cells in PCa tissues. Conversely, B and NK cell infiltration was increased significantly

M2 macrophages, CD8+ T cells, resting NK cells, memory B cells and activated dendritic cells showed a positive correlation with the malignancy of PCa

Naive B cells, resting dendritic cells and activated NK cells demonstrated a negative correlation with the degree of malignancy

Shao et al.

Develop a gene signature for predicting PCa prognosis

Biochemical recurrence; overall survival

Patients with a low-risk score exhibited significantly longer overall survival (OS) compared with the high-risk score group (p = 0.01, 0.04, 0.02, respectively)

The signature also indicated a higher likelihood of regulatory T cell (Treg) infiltration, as well as infiltration of both M1 and M2-polarized macrophages in patients with a high-risk score and prostate cancer (PCa)

Furthermore, patients with a higher Gleason score demonstrated increased infiltration of M2-polarized macrophages

Zhang et al.

Evaluate tumor-infiltrating M2 macrophages (TIMMs) in localized PCa and explore its correlation with clinical parameters

Recurrence-free survival

Patients with high tumor-infiltrating immune microenvironment (TIMMs) experienced significantly poorer recurrence-free survival (RFS)

Watanabe et al.

Evaluate the infiltration of CCR4+ regulatory T cells (Tregs) in prostate cancer tissues; clarify the relationship between CCR4+ Treg infiltration and clinical outcomes (Gleason score, PSA, time to castration-resistant prostate cancer (CRPC))

Time of progression to castration-resistant prostate cancer; Gleason score; PSA levels; survival time

In biopsy specimens, 65.9% Tregs were positive for CCR4. The number of CCR4+ Tregs positively correlated with clinical stage (p < 0.001) and Gleason score (p = 0.006). The poor prognosis group exhibited a significant increase in the total number of regulatory T cells (Tregs) and CCR4+ Tregs compared to the good prognosis group (p = 0.024 and 0.01, respectively)

Lower levels of CCR4+ Tregs correlated to a significantly longer time to progression to castration-resistant prostate cancer (CRPC) (not reached vs 27.3 months; p < 0.001) and a higher median survival time (not reached vs. 69.0 months; p = 0.014)

Meng et al.

Associations between TIICs and recurrence-free survival (RFS)

Recurrence-free survival

An increased proportion of M2 macrophages in prostate cancer (PCa) is linked to a poor prognosis, with a mean recurrence-free survival (RFS) of 819.11 days. Conversely, a lower proportion of M2 macrophages is associated with a more prolonged RFS, with a mean RFS of 992.65 days (p = 0.025)

Nardone et al.

Use tumor immune lymphocyte infiltration of tumor tissues for predicting prostate cancer outcome

Overall survival, post radiotherapy progression-free survival (PFS), biochemical progression-free survival (bPFS)

Higher peripheral stromal CD8 and lower PD-1 TIL scores correlated to a longer biochemical PFS

Higher peripheral stromal CD8 and intratumoral CCR7 TIL scores correlated to a prolonged PFS and OS

Lower peripheral stromal CD45 and peripheral stromal FoxP3 TIL scores correlated to a prolonged PFS and OS

Zeigler-Johnson et al.

Understanding prostatic inflammation by infiltrating lymphocytes and macrophages characterized by severity of the cancer

Time to biochemical failure

Regardless of obesity status, advanced tumor grade was significantly associated with higher CD68 cell counts (p = 0.019)

In contrast, higher CD8 cell counts was linked to an increased biochemical failure

Davidsson et al.

Investigate the associoation between T helper cells, T cytotoxic cells, or CD4+ Treg cells and lethal prostate cancer

Cancer-specific mortality; All-cause mortality

Men who have a higher abundance of CD4+ regulatory T cells (Tregs) within their prostate tumor microenvironment face an increased risk of succumbing to the disease

On the other hand, there was no observed association between T cytotoxic cells and lethal prostate cancer

Nonomura et al.

To access the use of prostate infiltrating tumor associate macrophages for prognosis after hormonal therapy

Recurrence-free survival

Tumor-associated macrophages (TAMs) count is positively correlated with higher serum PSA levels, higher Gleason score, advanced clinical stage and PSA failure

Furthermore, patients with lower TAM counts have better recurrence-free survival compared to those with higher TAM counts (p < 0.001)

Nonomura et al.

Access the potential of mast cell accumulation around prostate cancer (PCa) as a prognostic factor

PSA-free survival

Elevated mast cell counts are significantly correlated with better prostate-specific antigen (PSA)-free survival compared to those with lower mast cell counts (p < 0.001)

Andersen et al.

Evaluate and characterize the potential of different immune cell as prognostic markers of prostate cancer

Biochemical recurrence

The presence of elevated levels of infiltrating regulatory T cells (Tregs), as well as M1 and M2 macrophages in the stroma and/or epithelium, was found to be significantly correlated with biochemical recurrence (p < 0.05)

Erlandsson et al.

Assess the prognostic value of M2 macrophages in a large cohort of prostate cancer patients

Overall survival

Men who exhibited a high abundance of M2 macrophages had approximately double the odds of experiencing prostate cancer-related mortality (odds ratio: 2.05; 95% confidence interval 1.46–2.88)

Yang et al.

Construct a prognostic model with the immune infiltration landscape for PCa status

Overall survival; Disease-free survival

Enrichment of neutrophils (p = 0.024), and M2 macrophages (p = 0.007) in high-risk group while the low-risk group exhibited a significant accumulation of CD4-activated memory T cells (p = 0.017)

Feng et al.

Develop a predictive model for prostate cancer (PCa) progression using CIC (cancer-interacting cell)-related genes

Progression-free survival (PFS)

Tumor samples displayed elevated counts of myeloid dendritic cells, macrophages and T cells compared to the non-tumor samples

Levels of mast cells, neutrophils, T helper type 1 (Th1) cells and NK cells were significantly decreased in patients with a high-risk score

Zhang et al.

The dysregulation of glycolytic enzymes and its impact on prostate cancer (PCa)

Progression-free survival

There was a significant negative association between higher risk scores and lower levels of NK cell infiltration, neutrophil cell infiltration and macrophage M2 cell infiltration. Conversely, higher risk scores were significantly positively correlated with increased levels of myeloid dendritic cell infiltration in PCa

Zhao et al.

Develop and validate an immune-related gene (IRG)-based signature to predict the prognosis of prostate adenocarcinoma (PRAD)

Biochemical failure

The high-risk group exhibited elevated infiltration levels of regulatory T cells and CD4+ memory-activated T cells compared to the low-risk group (p < 0.05)

In contrast, the high-risk group displayed significantly reduced infiltration of neutrophils, monocytes and activated mast cells (p < 0.05)

Higher infiltration levels of CD8+ T cells was mostly found in the high-risk group

Zhang et al.

To develop a predictive model for assessing the prognostic risk of patients

Disease-free survival: biochemical recurrence; cancer-specific death

There was a notable increase in the infiltration of M0, M1, M2 macrophages, naive B cells and plasma cells within the tumor microenvironment of the high-risk group

A significantly higher infiltration of activated mast cells, CD8 T cells, resting dendritic cells, monocytes and activated dendritic cells in the low-risk group

Rui et al.

Assess the extent of prostate infiltration by immune cells and to examine the association between tumor recurrence and immune cells

Cancer recurrence

Th2 cells and Tcm cells exhibit a beneficially protective role in reducing prostate cancer recurrence (HR < 1)

There is an inverse relationship between the extent of infiltration of Th2 cells and Tcm cells and the recurrence prostate cancer, with higher levels of infiltration associated with lower recurrence rates