Abstract
Elevated neutrophil/lymphocyte (NLR) and platelet/lymphocyte ratios (PLR) have been recognized as poor prognostic indicators at time of cancer diagnosis. There is no data on whether a progressive increase of these ratios can be early indicators of cancer development.
We analyzed the lung cancer (LC) cases detected in the Pamplona Lung Cancer Screening Program between 2001 and 2015. Complete blood counts (CBC) were registered at annual intervals between enrolment and time of diagnosis. Linear regression analysis was used to calculate the mean annual change in NLR and PLR in those with at least 3 CBCs. Results were compared to a matched group of participants who didn't develop LC.
Thirty-two out of 55 LC had at least 3 CBCs before diagnosis. At enrolment, NLR and PLR were similar between subjects who developed LC (n=32) and controls (n=103) (Table 1). After a median follow-up of 80 months and a median of 4 (IQR 3-6) CBCs, subjects who developed LC showed faster NLR and PLR annual progressions (2.56% vs. 0.27% [p=0.4] per year; and 3.75% vs. 0.33% [p=0.02] per year, respectively) (Table 2). Annual NLR and PLR change was associated to a 3% (HR 1.03; CI95% 0.98-1.1, p=0.2) and 5% increase in LC risk (HR 1.05; CI95% 1.0-1.1, p=0.04), respectively.
In a LC screening setting, a progressive increase in PLR could suggest lung cancer development. Larger studies are needed to confirm this observation.
- Copyright ©ERS 2015
