# Diagnostic value of CRP, PCT, NC, and NLR in peripheral blood for bacterial infections in non-small cell lung cancer patients after chemotherapy

## TL;DR

This study finds that PCT and NLR blood markers can help detect bacterial infections in lung cancer patients after chemotherapy.

## Contribution

The study identifies PCT and NLR as effective biomarkers for diagnosing bacterial infections in NSCLC patients post-chemotherapy.

## Key findings

- CRP, PCT, NC, and NLR levels were significantly higher in infected NSCLC patients.
- PCT showed the highest diagnostic accuracy (AUC=1.000), followed by NLR (AUC=0.981).
- Combining PCT and NLR may improve early detection of infections in these patients.

## Abstract

This study aimed to evaluate and compare the diagnostic value of C-reactive protein (CRP), procalcitonin (PCT), neutrophil count (NC), and neutrophil-to-lymphocyte ratio (NLR) in peripheral blood for detecting bacterial infections in patients with non-small cell lung cancer (NSCLC) following chemotherapy.

A total of 122 NSCLC patients treated at our hospital between October 2021 and October 2024 were enrolled. Of these, 72 patients with confirmed bacterial infections post-chemotherapy were assigned to the infection group, while 50 patients without infections were included in the non-infection group. General clinical data, overall survival, and levels of CRP, PCT, NC, and NLR were compared between groups.

Levels of CRP, PCT, NC, and NLR were significantly higher in the infection group compared to the non-infection group (P<0.05). There was no significant difference in overall survival between the two groups (P=0.749). Receiver operating characteristic (ROC) curve analysis showed that all four biomarkers had statistically significant diagnostic value (P<0.05), with PCT demonstrating the highest AUC (1.000), followed by NLR (0.981).

PCT and NLR are valuable biomarkers for diagnosing bacterial infections in NSCLC patients after chemotherapy. Due to their complementary diagnostic strengths, PCT offers high specificity and NLR high sensitivity, and their combined use may enhance early detection and improve clinical decision-making.