Ringed fluorodeoxyglucose uptake predicted poor prognosis after resection of pulmonary pleomorphic carcinoma

Pulmonary pleomorphic carcinoma (PPC) is a relatively rare and poorly differentiated non-small cell carcinoma. This study aimed to investigate the clinicopathological features including programmed cell death ligand 1 (PD-L1) expression status in patients with PPC who underwent curative resection.

We retrospectively studied 29 consecutive patients who had undergone anatomical lung resections for PPC. Perioperative and pathological variables, including radiological findings, were investigated to define prognostic factors.

Overall survival (OS) rates were 71.8% at 1 year and 60.0% at 5 years. Disease-free survival (DFS) rates were 54.8% at 1 year and 43.6% at 5 years. Univariate analysis revealed that ringed fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) (p = 0.003), a cavity in the tumor on CT (p = 0.004), and tumor size (> 40 mm) (p = 0.014) were poor prognostic factors for OS. Regarding DFS, ringed FDG uptake (p = 0.002), a cavity on CT (p < 0.001), tumor size (p = 0.007), and pleural invasion (p = 0.014) were poor prognostic factors. PD-L1 expression was not a prognostic factor.

This study showed for the first time that ringed FDG uptake on PET/CT is a poor prognostic factor of PPC. PD-L1 expression status was not related to the prognosis. Trial registration The study was approved by the Kobe City Medical Center General Hospital's ethics board (No. 20112) on August 20, 2020.