Correlation of PD-L1 expression on tumour cells between diagnostic biopsies and surgical specimens of lung cancer in real life with respect to biopsy techniques and neoadjuvant treatment.

PURPOSES: Programmed death-ligand 1 (PD-L1) testing is performed mainly on biopsy specimens in patients with advanced lung cancer. It is questionable whether the small amount of tissue analysed in biopsies may represent the true PD-L1 expression of a tumour. METHODS: In this retrospective study, PD-L1 expression on tumour cells derived from bronchoscopy brush cytology, endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA), endobronchial biopsy, transbronchial biopsy (TBB) and computed tomography (CT)-guided transthoracic biopsy was compared to the PD-L1 expression of the corresponding surgical resection in lung cancer patients with regard to neoadjuvant treatment in-between. RESULTS: A quantitative comparison between the diagnostic biopsy of the primary tumour with corresponding resected surgical specimens in a total of 113 lung cancer patients (60% male, mean age 65 ± 9 years) revealed a statistically significant correlation of PD-L1 expression on tumour cells (r = 0.58, p< 0.001), for patients without neoadjuvant treatment in-between and for patients who underwent neoadjuvant treatment (both p < 0.001). Using a cut-off value of ≥ 50% PD-L1 TPS for comparing the biopsy samples and resected specimens, the concordance rate was 78% with a Cohen's Kappa of 0.45. CONCLUSION: A statistically significant concordance for PD-L1 expression on tumour cells between biopsies from primary lung tumour and resected specimen was found, but of uncertain clinical accuracy. The use of a cut-off value of ≥ 50% PD-L1 TPS resulted only in a moderate agreement. Therefore, the interpretation of the PD-L1 determined form biopsy specimens status should only be considered with caution for treatment decisionsQuery.

Neoadjuvant chemoradiotherapy is superior to chemotherapy alone in surgically treated stage III/N2 non-small-cell lung cancer: a retrospective single-center cohort study.

BACKGROUND: There is lack of consensus whether neoadjuvant chemoradiotherapy (CHT/RT) is superior to neoadjuvant chemotherapy (CHT) alone in patients with potentially resectable stage III/N2 non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: We retrospectively evaluated clinical parameters and outcomes in patients with clinical stage III/N2 NSCLC treated with neoadjuvant CHT/RT versus CHT followed by surgery. Nearest-neighbor propensity score (PS) matching was used to correct for pretreatment differences. RESULTS: A total of 84 patients were enrolled. Thirty-four (40%) and 50 (60%) patients received CHT/RT or CHT followed by curative-intent surgery, respectively. Overall 90-day mortality and morbidity were 0% versus 0.04% and 21% versus 18%, respectively, with no significant difference between the CHT/RT and the CHT-alone cohorts (P = 0.51 and P = 0.70). In the PS-matched cohort, complete pathological response was recorded in 25% after CHT/RT versus 0% after CHT at the time of surgery. Patients receiving neoadjuvant CHT/RT exhibited significantly better 5-year disease-free survival (DFS) [45% versus 16% CHT group; hazard ratio (HR) 0.43, P = 0.04]; 5-year overall survival (OS) was 75% after CHT/RT and 21% after CHT (HR 0.37, P = 0.001). CHT/RT more often induced pathological mediastinal downstaging (P = 0.007), but CHT/RT remained the only independent factor for DFS and OS and did not depend on mediastinal downstaging. CONCLUSIONS: In this retrospective PS-matched long-term analysis, neoadjuvant CHT/RT conferred improved DFS and OS compared with CHT alone in stage III/N2 NSCLC. These highly challenging results require confirmation in well-designed randomized controlled trials conducted at highly specialized thoracic oncology centers.