Filippo Lococo1, Federica Torricelli2, Giulio Rossi3, Marco Alifano4, Diane Damotte5, Cristian Rapicetta6, Ione Tamagnini7, Alberto Cavazza7, Simonetta Piana7, Carla Galeone6, Massimiliano Paci6, Alessia Ciarrocchi2. 1. Unit of Thoracic Surgery, Arcispedale Santa Maria Nuova-IRCCS, Reggio Emilia, Italy. Electronic address: filippo_lococo@yahoo.it. 2. Laboratory of Translational Research, Research and Statistic Infrastructure, Arcispedale Santa Maria Nuova-IRCCS, Reggio Emilia, Italy. 3. Unit of Pathology, Azienda USL Valle d'Aosta, Regional Hospital "Parini", Aosta, Italy. 4. Thoracic Surgery Department, Cochin Hospital, AP-HP, Paris, France; Université Paris Descartes, Paris, France. 5. Pathology Department, Cochin Hospital, AP-HP, Paris, France; Université Paris Descartes, Paris, France. 6. Unit of Thoracic Surgery, Arcispedale Santa Maria Nuova-IRCCS, Reggio Emilia, Italy. 7. Unit of Pathology, Arcispedale Santa Maria Nuova-IRCCS, Reggio Emilia, Italy.
Abstract
INTRODUCTION: Pulmonary Sarcomatoid Carcinoma (PSC) is a rare subset of NSCLC, associated with worse prognosis and resistant to platinum-based regimens. Recent investigations have shown high levels of PD-L1 expression in PSC, providing a rationale for the potential use of immunotherapy. In this study, we investigated whether the PD-L1 expression was related to clinico-pathologic and molecular characteristics. MATERIALS AND METHODS: Fortythree surgically-resected PSCs were selected from 2006 to 2014 and clinical information retrieved. PD-L1 expression was analyzed by immunohistochemistry and correlated with the clinic-pathologic features and driver gene mutations analyzed by Next-Generation-Sequencing. Correlation of clinical, pathological and genetic variants with PD-L1 expression positivity were tested by Fisher's exact test analysis. RESULTS: About 25% of PSCs showed a significant expression of PD-L1 (positive staining defined as staining in ≥10% of tumor cells). PD-L1 expression was associated with aggressive pathological features of PSCs including N2-involvement (PD-L1 positive in 83.3% of N2-PSCs vs in 16.2% of N0/N1-PSCs, p=0.003) and presence of either local (p=0.038) and distant metastases (p=0.022). Furthermore, PD-L1 expression was significantly associated with the overall mutational load of the tumors (PD-L1 positivity only in PSCs with at least one mutational event) and in particular with the presence of KRAS mutation (PD-L1 positive in 44.4% of KRAS-Mut PSCs vs 12.0% in KRAS-Wild PSCs). The correlation between PD-L1 expression and KRAS-mutation were found at univariate analysis (p=0.031), even considering PD-L1 as a continuous variable (p=0.018), and confirmed at multivariate analysis (p=0.035). The mutational status of the other genes explored in the NGS-panel (EGFR, APC, PTEN, PIK3CA, TP53 and STK11) did not correlate with PD-L1 expression. CONCLUSIONS: PD-L1 expression significantly correlates with overall mutational load and KRAS mutational status in pulmonary sarcomatoid carcinomas.
INTRODUCTION:Pulmonary Sarcomatoid Carcinoma (PSC) is a rare subset of NSCLC, associated with worse prognosis and resistant to platinum-based regimens. Recent investigations have shown high levels of PD-L1 expression in PSC, providing a rationale for the potential use of immunotherapy. In this study, we investigated whether the PD-L1 expression was related to clinico-pathologic and molecular characteristics. MATERIALS AND METHODS: Fortythree surgically-resected PSCs were selected from 2006 to 2014 and clinical information retrieved. PD-L1 expression was analyzed by immunohistochemistry and correlated with the clinic-pathologic features and driver gene mutations analyzed by Next-Generation-Sequencing. Correlation of clinical, pathological and genetic variants with PD-L1 expression positivity were tested by Fisher's exact test analysis. RESULTS: About 25% of PSCs showed a significant expression of PD-L1 (positive staining defined as staining in ≥10% of tumor cells). PD-L1 expression was associated with aggressive pathological features of PSCs including N2-involvement (PD-L1 positive in 83.3% of N2-PSCs vs in 16.2% of N0/N1-PSCs, p=0.003) and presence of either local (p=0.038) and distant metastases (p=0.022). Furthermore, PD-L1 expression was significantly associated with the overall mutational load of the tumors (PD-L1 positivity only in PSCs with at least one mutational event) and in particular with the presence of KRAS mutation (PD-L1 positive in 44.4% of KRAS-Mut PSCs vs 12.0% in KRAS-Wild PSCs). The correlation between PD-L1 expression and KRAS-mutation were found at univariate analysis (p=0.031), even considering PD-L1 as a continuous variable (p=0.018), and confirmed at multivariate analysis (p=0.035). The mutational status of the other genes explored in the NGS-panel (EGFR, APC, PTEN, PIK3CA, TP53 and STK11) did not correlate with PD-L1 expression. CONCLUSIONS:PD-L1 expression significantly correlates with overall mutational load and KRAS mutational status in pulmonary sarcomatoid carcinomas.