Programmed Cell Death Ligand 1 Expression in Resected Non–Small Cell Lung Cancer

BackgroundRecently, anti–programmed cell death 1 (PD-1) and anti–programmed cell death ligand 1 (PD-L1) immunotherapies have yielded promising outcomes for patients with advanced non–small cell lung cancer (NSCLC) and led to great interest in applying these agents to treat resectable early-stage NSCLC. The objective of our study was to evaluate PD-L1 protein expression in resectable early-stage NSCLC specimens from a large Northern European cohort, examine the relationship to clinical characteristics, and demonstrate the prognostic role in resected NSCLC.Materials and MethodsA large cohort of 875 NSCLC tumors consisted of 337 patients from Sweden and 538 patients from Norway was studied. All the patients had undergone pulmonary resection, and most patients had had early-stage NSCLC. PD-L1 protein expression was assessed by immunohistochemistry using the Dako PD-L1 22C3 pharmDx kit. The tumor proportion score for PD-L1 protein expression was compared with comprehensive demographic and clinicopathologic data.ResultsThe overall prevalence of PD-L1 protein expression in the resectable NSCLC cohort was 9.5% at a tumor proportion score cutoff of ≥ 50%. Stage I NSCLC had lower PD-L1 expression compared with that of the other stages (P = .0012). PD-L1 expression correlated with wild-type EGFR gene expression (P = .0156) and mutated KRAS gene expression (P = .0004). No significant association was found between PD-L1 expression and mortality after multivariable adjustment for clinical characteristics, although the survival curves showed PD-L1 expression significantly correlated with a poor prognosis in the total NSCLC cohort and in the adenocarcinoma subgroup.ConclusionPD-L1 expression in the present large cohort of resectable NSCLC was relatively low compared with data from clinical trials of advanced NSCLC. PD-L1 expression correlated positively with tumor stage, wild-type EGFR, and KRAS mutation. PD-L1 expression was not found as an independent prognostic factor in the present study. These findings could be important in the future when evaluating the role of anti–PD-1/PD-L1 immunotherapy in the setting of neoadjuvant or adjuvant trials for early-stage resectable NSCLC.     

Efficacy of Crizotinib among Different Types of ROS1 Fusion Partners in Patients with ROS1-Rearranged Non–Small Cell Lung Cancer

Introduction

ROS1 rearrangement–positive NSCLC can be treated effectively with an anaplastic lymphoma kinase/ROS1/mesenchymal-epithelial transition factor inhibitor such as crizotinib; however, the rate of response remains variable. Although several ROS1 fusion partners have been identified, the efficacy of crizotinib in patients with different types of ROS1 fusion partners is poorly understood.

Characteristics and Outcome of ROS1-Positive Non–Small Cell Lung Cancer Patients in Routine Clinical Practice

Introduction

ROS1-rearranged NSCLC is classified as a distinct molecular subset of NSCLC with a therapeutic target. ROS1 rearrangement is most often identified in never-smokers with adenocarcinoma and EGFR and ALK receptor tyrosine kinase gene (ALK) wild type. Treatment with tyrosine kinase inhibitors (TKIs), which target the ROS1 kinase domain, is considered the standard of care. TKIs have been shown to have a robust and durable response. However, information regarding the clinical outcomes of TKI treatment, including brain metastasis, remains limited.

Ablative Therapy for Oligometastatic Non–Small Cell Lung Cancer

The oligometastatic state represents a distinct entity among those with metastatic disease and consists of patients with metastases limited in number and location, representing an intermediate state between locally confined and widely metastatic cancer. Although similar, “oligorecurrence” (limited number of metachronous metastases under conditions of a controlled primary lesion) and “oligoprogressive” (disease progression at a limited number of sites with disease controlled at other disease sites) states are distinct entities. In non–small cell lung cancer (NSCLC), the oligometastatic state is relatively common, with 20% to 50% of patients having oligometastatic disease at diagnosis. This subgroup of patients when receiving ablative therapy, such as surgery or stereotactic body radiation radiotherapy, can obtain markedly long progression-free and overall survival. The role of radical treatment for intracranial oligometastases is well established. Fewer data exist regarding radical treatment of extracranial metastases in lung cancer; however, retrospective series using surgery or stereotactic body radiotherapy for extracranial oligometastatic disease in NSCLC have shown excellent local control, with a suggestion of improvement in progression-free survival. In the present report, we have reviewed the data on the treatment of brain metastases in oligometastatic NSCLC and the results of ablative treatment of extracranial sites. Recently, the first randomized trial comparing ablative treatment versus control in oligometastatic disease was reported, and those data are reviewed in the context of smaller series. Finally, areas of controversy are discussed and a therapeutic approach for patients with oligometastatic disease is proposed.