Platelet-to-Lymphocyte Ratio as an Indicator to Predict Decreased Carbon Monoxide Diffusion of the Lung in Patients with Testicular Cancer

Objective: To investigate whether the use of diffusing capacity of the lungs for carbon monoxide (DLCO) and neutrophil-to-lym-phocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) could be used to predict bleomycin-induced pulmonary toxicity in patients with testicular cancer (TCa). Study Design: Descriptive study. Place and Duration of Study: Ankara Oncology Training and Research Hospital, Turkey, between 2017 and 2020. Methodology: Data of 40 patients with TCa, who were followed at cancer centre from 2017-2020 and received 3-4 cycles of BEP protocol were retrospectively screened and included who met the criteria for inclusion in the study. All patients with TCa, who were older than 18 years of age and had no secondary malignancy and comorbidity, were included in this study. Results: A statistically significant negative correlation was found between DLCO change and NLR, PLR (r:-0.558, p:0.002 for NLR; r:-0.462 p:0.012 for PLR). A statistically significant positive correlation was found between DLCO change and lymphocyte level (r:0.436, p:0.018). The NLR and PLR were statistically higher in the group with a decrease of >_10% in DLCO compared to the group with no decrease or a decrease of <= 10% in DLCO (for NLR; 3.03 +/- 1.45 and 1.68 +/- 0.73, respectively, p = 0.005; for PLR 187.72 +/- 66.90 and 124.72 +/- 47.99, respectively, p = 0.008). Multivariate regression analysis showed a statistically significant relationship between PLR increase and a decrease of >_10% in DLCO. Conclusion: PLR and LDH could be used as independent predictive biomarkers for DLCO decline which is used to identify bleomycin-induced pulmonary toxicity.