Peripheral blood lymphocyte subsets are associated with the clinical outcomes of prostate cancer patients

Background: Many studies have sought associations between the total peripheral blood lymphocyte count and prostate cancer (PCa) prognosis, but not peripheral lymphocyte subsets. We explored the associations between the absolute counts of peripheral lymphocyte subsets and PCa patient survival.Methods: 135 PCa patients were included in this study. The log-rank test and Kaplan-Meier method were employed to compare overall survival (OS) and progression-free survival (PFS) rates. Univariate and multivariate Cox's regression analyses were employed to identify prognostic factors. Flow cytometry analysis was used to determine the numbers of peripheral lymphocyte subsets.Results: PCa patients with lower absolute counts of certain lymphocyte subsets showed poorer PFS and OS than those with higher absolute counts of these cells. The numbers of CD4+ T cells, CD3+ T cells, and natural killer (NK) cells were significantly higher in PCa patients of tumor node metastasis (TNM) I-II stages than those of TNM IIII-IV stages. Univariate and multivariate Cox's regression analyses of OS and PFS indicated that neutrophil numbers > 4.81*109/L, CD4+T cells <= 254 /mu L, and NK cells <= 136 /mu L were unfavorably prognostic for patients with PCa.Conclusions: Lower absolute counts of certain peripheral lymphocyte subsets (NK cells <= 136/mu L and CD4+ T cells <= 254/mu L) are prognostically unfavorable for PCa patients.