PURPOSE: Eliciting antitumor T-cell response by targeting the PD-1/PD-L1 axis with checkpoint inhibitors has emerged as a novel therapeutic strategy in non-small cell lung cancer (NSCLC). The identification of predictors for sensitivity or resistance to these agents is, therefore, needed. Herein, we investigate the correlation of metabolic information on FDG-PET with tissue expression of immune-checkpoints and other markers of tumor-related immunity in resected NSCLC patients. MATERIALS AND METHODS: All patients referred to our institution for upfront surgical resection of NSCLC, who were investigated with FDG-PET prior to surgery, were consecutively included in the study. From January 2010 to May 2014, 55 patients (stage IA-IIIB; M:F = 42:13; mean age 68.9 years) were investigated. Sampled surgical tumor specimens were analyzed by immunohistochemistry (IHC) for CD68-TAMs (tumor-associated macrophages), CD8-TILs (tumor infiltrating lymphocytes), PD-1-TILs, and PD-L1 tumor expression. Immunoreactivity was evaluated, and scores were compared with imaging findings. FDG-PET images were analyzed to define semi-quantitative parameters: SUVmax and SUVmean. Metabolic information on FDG-PET was correlated with tissue markers expression and disease-free survival (DFS) considering a median follow-up of 16.2 months. RESULTS: Thirty-six adenocarcinomas (ADC), 18 squamous cell carcinomas (SCC), and one sarcomatoid carcinoma were analyzed. All tumors resulted positive at FDG-PET: median SUVmax 11.3 (range: 2.3-32.5) and SUVmean 6.4 (range: 1.5-13) both resulted significantly higher in SCC compared to other NSCLC histotypes (p = 0.007 and 0.048, respectively). IHC demonstrated a median immunoreactive surface covered by CD68-TAMs of 5.41 % (range: 0.84-14.01 %), CD8-TILs of 2.9 % (range: 0.11-11.92 %), PD-1 of 0.65 % (range: 0.02-5.87 %), and PD-L1 of 0.7 % (range: 0.03-10.29 %). We found a statistically significant correlation between SUVmax and SUVmean with the expression of CD8 TILs (rho = 0.31; p = 0.027) and PD-1 (rho = 0.33; p = 0.017 and rho = 0.36; p = 0.009, respectively). The other tissue markers correlated as follows: CD8 TILs and PD-1 (rho = 0.45; p = 0.001), CD8 TILs and PD-L1 (rho = 0.41; p = 0.003), CD68-TAMs and PD-L1 (rho = 0.30; p = 0.027), PD-1 and PD-L1 (rho = 0.26; p = 0.059). With respect to patients' outcome, SUVmax, SUVmean, and disease stage showed a statistically significant correlation with DFS (p = 0.002, 0.004, and <0.001, respectively). CONCLUSIONS: The present study shows a direct association between metabolic parameters on FDG-PET and the expression of tumor-related immunity markers, suggesting a potential role for FDG-PET to characterize the tumor microenvironment and select NSCLC patients candidate to checkpoint inhibitors.
Correlation of metabolic information on FDG-PET with tissue expression of immune markers in patients with non-small cell lung cancer (NSCLC) who are candidates for upfront surgery / E. Lopci, L. Toschi, F. Grizzi, D. Rahal, L. Olivari, G. F. Castino, S. Marchetti, N. Cortese, D. Qehajaj, D. Pistillo, M. Alloisio, M. Roncalli, P. Allavena, A. Santoro, F. Marchesi, A. Chiti. - In: EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING. - ISSN 1619-7070. - 43:11(2016 Oct), pp. 1954-1961.
|Titolo:||Correlation of metabolic information on FDG-PET with tissue expression of immune markers in patients with non-small cell lung cancer (NSCLC) who are candidates for upfront surgery|
MARCHESI, FEDERICA (Corresponding)
|Parole Chiave:||FDG-PET; Immunometabolism; NSCLC; PD-L1; TAMs; TILs; Tumor-related immunity|
|Settore Scientifico Disciplinare:||Settore MED/04 - Patologia Generale|
|Data di pubblicazione:||ott-2016|
|Data ahead of print / Data di stampa:||1-giu-2016|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s00259-016-3425-2|
|Appare nelle tipologie:||01 - Articolo su periodico|