Can the systemic immune-inflammation index be used to differentiate benign and malignant pathologies before transrectal ultrasound-guided prostate biopsy?

BACKGROUND

This study aimed to evaluate the ability of the systemic immune-inflammation index (SII), which is tested before transrectal ultrasound-guided systematic prostate biopsy, to predict the histopathology of non-malignant and malignant prostate tissue.

METHODS

Data from 1040 patients who underwent transrectal ultrasound-guided prostate biopsy between June 2019 and January 2023 due to high prostate-specific antigen levels or palpation of suspicious prostate cancer nodules via digital rectal examination were analyzed retrospectively. The patients were divided into two groups as biopsy negative and prostate cancer. The SII, platelet/lymphocyte ratio (PLR), and neutrophil/lymphocyte ratio (NLR) were compared between the two groups. Statistical analyses were performed using Student's t, Mann-Whitney U, and one-way ANOVA tests, along with ROC curve analysis and DeLong's test to assess diagnostic performance.

RESULTS

There was no difference between the groups in terms of the SII, PLR, or NLR (p > 0.05). When evaluated according to the European Urology Association risk groups for biochemical recurrence of localized and locally advanced prostate cancer based on systematic biopsy, a significant difference was observed in the SII and PLR markers between the groups with biopsy negative and those with high-risk prostate cancer (p = 0.009, and p < 0.001, respectively). In the ROC analysis, the AUC for the SII was 0.568 (95% CI 0.523-0.628). The best limit value was determined to be 591.4, and for values ≥ 591.4, the sensitivity was determined to be 0.5, and the specificity was 0.571. For the PLR, the AUC was 0.618 (95% CI 0.559-0.676). The best limit value was 139.6, and for values ≥ 139.6, the sensitivity was 0.52, and the specificity was 0.72.

CONCLUSIONS

Hematological inflammatory parameters before prostate biopsy are not effective markers for distinguishing between biopsy negative and malignant pathologies. The inflammatory markers SII and PLR can be used as diagnostic tools in high-risk prostate cancer patients but cannot be used as markers for the detection of pathologies in low- and intermediate-risk patients.