Increased tumor-associated macrophages in the prostate cancer microenvironment predicted patients' survival and responses to androgen deprivation therapies in Indonesian patients cohort.

BACKGROUND

Tumor-associated macrophages (TAMs) and microvessel density (MVD) play an essential role for tumor progression in prostate cancer (PCa). In this study, we evaluated the association between TAMs, the infiltration with tumor angiogenesis and the response to androgen deprivation therapies (ADTs) in PCa to evaluate TAM infiltration as a predictive factor for PCa survival.

MATERIALS AND METHODS

Fifty-four specimens were collected and stained with CD 68 antibody to investigated TAM infiltration in tumor. Von Willebrand factor was stained to evaluate MVD around the cancer foci. We assessed the association between patient's age, preoperative serum prostate-specific antigen, pathologic Gleason sum (GS), TAM infiltration, MVD, and the response to ADT for 5 years after PCa diagnosis.

RESULTS

The median TAM was observed in 28 (6-76)/high power field (x400). Increasing TAM correlated with increasing tumor angiogenesis ( < 0.001, r = 0.61), and the response to ADT was significantly better in patients with fewer TAMs (<28) than in patients with higher TAMs (>28) ( = 0.003). TAM infiltration was significantly higher in those with higher serum prostate-specific antigen, higher GS, and metastasis. Multivariate analysis showed that GS, ADT type, and MVD number were significant prognostic factors for response to ADT in PCa ( < 0.0001). An increased infiltration of TAM [hazards ratio (HR) = 4.47; 95% confidence interval (CI): 1.97-10.15], MVD (HR = 2.66; 95% CI: 1.27-5.61), metastatic status (HR = 2.29; 95% CI: 0.14-0.60), and prostate volume (HR = 2.19; 95% CI: 1.27-3.12) significantly correlated with shorter survival in PCa patients by univariate analysis ( < 0.05). Multivariate analyses revealed that TAM and metastatic status significantly correlated with poor overall survival.

CONCLUSIONS

TAM infiltration is associated with response to ADT and increased tumor angiogenesis in PCa. GS, ADT type, and MVD in PCa specimens are useful predictive factors for poor response to ADT. Increasing TAM and positive metastatic status were prognostic factors for a poorer survival in PCa patients.