Hedgehog signaling pathway is physiologically activated during embryogenesis, especially in lung development. It is also reactivated in many solid tumors. In lung cancer, Hedgehog pathway is closely associated with cancer stem cells (CSCs). Recent works have shown that CSCs produced a full-length Sonic Hedgehog (Shh) protein, with paracrine activity and induction of tumor development. Hedgehog pathway is also involved in tumor drug resistance in lung cancer, as cytotoxic chemotherapy, radiotherapy, and targeted therapies. This review proposes to describe the activation mechanisms of Hedgehog pathway in lung cancer, the clinical implications for overcoming drug resistance, and the perspectives for further research.

Hedgehog (Hh) and Wingless-type (Wnt) pathways are associated with resistance to immune checkpoint inhibitors (ICIs) in preclinical studies. This study aimed to assess the association between expression and activation levels of Wnt and Sonic Hedgehog (Shh) pathways and resistance to ICIs in advanced NSCLC patients treated with ICI. Hh and Wnt pathways activation was assessed by immunohistochemistry (Gli1 and beta-catenin) on corresponding tumor tissues, and by plasma concentrations of Shh and Wnt (Wnt1, Wnt2 and Wnt3) at ICI introduction and at the first clinical evaluation. Sixty-three patients were included, with 36 patients (57.1%) with available tissue. Response rate was lower in Gli1+ NSCLC (20.0%) compared to Gli1 negative (Gli-) NSCLC (55.6%) (p = 0.015). Rate of primary resistance was 69.8%, vs. 31.2%, respectively (p = 0.04), and median progression-free survival (PFS) was 1.9 months (interquartile range (IQR) 1.2–5.7) vs. 6.1 months (1.6–26.0), respectively (p = 0.08). Median PFS and overall survival were shorter in case of increase of Wnt1 concentration during ICI treatment compared to other patients: 3.9 months vs. 11.2 months (p = 0.008), and 15.3 months vs. not reached (p = 0.003). In conclusion, baseline activation of Hh pathway and increase of Wnt1 concentrations during ICI treatment were associated with poor outcome in NSCLC patients treated with ICIs.

Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). An unmet need remains for new biomarkers associated with ICIs. In this study, consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab were included. Plasma at ICIs initiation was prospectively collected and a multiplex ELISA assay testing 48 cytokines and growth factors was performed. Exploratory endpoints were the association between plasma biomarkers with outcome and grade III–IV immune related adverse events (irAEs). Thirty-five patients were included. Patients without clinical benefit (n = 22) had higher pre-ICI soluble Hepatocyte Growth Factor (sHGF) (210.9 vs. 155.8 pg/mL, p = 0.010), lower pre-ICI soluble Fibroblast Growth Factor (sFGF) (4.0 vs. 4.8 pg/mL, p = 0.043) and lower pre-ICI interleukine-12 (IL-12) (1.3 vs. 2.2 pg/mL, p = 0.043) concentrations. Patients with early progression (n = 23) had higher pre-ICIs sHGF (206.2 vs. 155.8 pg/mL, p = 0.025) concentrations. Patients with low sHGF levels at ICIs initiation had longer progression-free survival and overall survival than those with high sHGF levels: respectively 2.5 vs. 8.0 months (p = 0.002), and 5.5 vs. 35.0 months (p = 0.001). TNF-α, IL-16, IL-12p40 and MCP3 were associated with high grade irAEs. This study shows the potential association between several plasma biomarkers with outcome and grade 3–4 IrAEs in advanced NSCLC treated with ICIs.

Lung cancer is a devastating disease affecting hundreds of thousands of patients in Europe. Despite recent advances in treatment, its prognosis remains poor. This is mainly attributed to the late stages that diagnoses are usually established at, consequently excluding curative treatment options. During the 2019 European Respiratory Society International Congress in Madrid, Spain, lung cancer experts presented the most recent aspects of lung cancer early detection with low-dose computed tomography.

E20543 Background: Nivolumab (NIV) is now widely used in ≥ 2^ndline of advanced non-small cell lung cancer (NSCLC). The aims of this real-life study were (1) to evaluate its efficacy, (2) to identify predictive factors of worsening under NIV. Methods: This retrospective multicentric study (8 Thoracic Oncology regional centers) included all patients treated by NIV in 2015 (follow-up until 2016, June 30^th). Demographics and tumor characteristics were extracted. Objective tumor response was assessed by computerized tomography (RECIST v1.1). Median NIV treatment duration and overall survival (OS) were calculated. Clinical and biological factors evaluated as predictive markers of earlyprogression (discontinuation before 1^stevaluation) were: NSCLC histology, PS, smoking-history, number of previous chemotherapy received and initial albumine (alb), C-reactive protein (CRP) and lactate dehydrogenase (LDH) serum levels. For these factors, patients quickly worsened and responders were compared (Student’s t-test, Chi-2 test). Results: Our cohort included 297 patients (non-squamous NSCLC n = 181 [61%]; PS > 1 n = 66 [22%]). At first evaluation, partial response was observed in 16% (n = 47), stable disease in 18% (n = 54) and progression in 49% (n = 144). A total of 45 patients (15%) were early progressors and no evaluation could be performed. Median NIV duration of treatment was 2.8 months [0-15], OS 6.9 months [0-16] (n = 146 still alive on June 30^th, 2016). Early progressor patients were PS > 1 in 42% versus (vs) 21% for responders (mean PS 1.7 vs 1.0 for responders (p < 0.001)) and an alb level of 29.9 g/L vs 33.6 (p = 0.03). Mean CRP (p = 0.06) and LDH (p = 0.08) serum levels, NSCLC histology (p = 0.64), smoking-history (p = 0.08), number of previous chemotherapy (p = 0.90) were non-significant. Conclusions: This study confirms that NIV may be effective in NSCLC, with a 16% objective response rate. However early progression observed in 15% of patients was associated with a lower initial alb level and a higher PS. Missing data for LDH and CRP levels may have influenced their non-significance. Further studies must be realized to determine the interest of these factors as predictive markers.