Role of sterile pyuria in association to elevated PSA values in the diagnosis of non-palpable prostate cancer?

Objectives: Although cancer is believed to develop and progress with the involvement of inflammation, it is still unclear what the correlation between inflammation and prostate cancer is. This study based on results of transrectal ultrasound-guided prostate biopsies aimed to determine whether C-reactive protein (CRP) and sterile pyuria were clinically useful in the evaluation of patients with suspect of prostate cancer.
Materials and methods: This study is a cross-sectional prospective study of patients without clinical prostatitis symptoms. Characteristics of the 200 consecutive patients recruited were 3-20 ng/mL value of serum prostate-specific antigen (PSA), normal digital rectal examination finding, and sterile urine culture result. All patients underwent 12-core prostatic biopsy. 163 of the 200 patients had benign prostatic hyperplasia confirmed through histology, while the residual 37 patients had prostate cancer. Patients with pre-treatment urinary leukocyte count ≤ 3/high power field were categorized as non-pyuria, whilst those with pre-treatment urinary leukocyte count > 3/high power field were categorized as pyuria. The serum CRP level was also used to differentiate patients before the biopsy. Subgroups were compared regarding a number of clinical variables.
Results: Histology revealed that 70% of pyuria patients and 38.5% of non-pyuria patients presented inflammation (p = 0.001). The pyuria group exhibited significantly higher total PSA compared to the non-pyuria group (p = 0.044). The two groups did not differ significantly regarding cancer detection rate (p = 0.752). CRP groups were similar regarding cancer detection and histologically-detected inflammation rates.
Conclusion: In patients with no evidence of clinical prostatitis, sterile pyuria should be considered as a cause of increased PSA. Although sterile pyuria cannot predict non-palpable prostate cancer, it should be taken into account in urological evaluation in order to demonstrate minute prostatic inflammation due to its simplicity, convenience and non-invasiveness.