Complementary prognostic markers are needed in thymic epithelial tumors (TETs) to
aid patient stratification and determine the most appropriate follow-up strategies.
This study aimed to assess the diagnostic and prognostic relevance of blood-based
inflammatory markers in a large cohort of surgically treated TET patients.A total
of 743 TET patients who underwent surgical resection between 1999-2021 were included
in this multicenter study. Inflammatory markers were recorded from the most recent
preoperative blood cell count prior to surgery. Measured variables were rescaled and
harmonized to obtain comparable values across the participating centers.Preoperative
CRP was significantly higher in TET patients with increased tumor size (vs. those
with T1 tumors, p = 0.035). Likewise, neutrophil-to-lymphocyte ratio (NLR) (p = 0.002)
and platelet-to-lymphocyte ratio (PLR) (p < 0.001) were both significantly higher
in thymic carcinomas than in thymomas. Notably, increased NLR and PLR were mainly
attributed to significantly decreased lymphocyte levels in thymic carcinoma patients.
Concerning survival outcomes, we found that elevated PLR and fibrinogen influenced
overall survival (OS) (p = 0.002 and p = 0.018, respectively) and cause-specific survival
(CSS) (p = 0.002 and p = 0.009, respectively) independently of other variables in
our multivariate models, and they constituted negative prognosticators in TETs. Elevated
CRP had an independent negative impact only on OS. Although elevated NLR was linked
with impaired prognosis in our univariate model (p = 0.008), its independent prognostic
significance could not be validated.Using the so-far largest cohort of surgically
treated TET patients, our study demonstrates that CRP, PLR, and NLR have diagnostic
significance in TETs, while elevated PLR and fibrinogen constitute independent negative
prognosticators for OS and CSS. Accordingly, the current multicenter study offers
additional guidance in developing personalized surveillance protocols in thymoma and
thymic carcinoma.
