As was clear at the British Thoracic Oncology Group (BTOG) 2019 Annual Conference in Dublin, Ireland, where the Association of Pulmonary Pathologists was in attendance, pathology is increasingly important in this era of molecular testing for lung cancer. Here, Alex Haragan, BSc, MBBS, MSc, of the University of Liverpool, Liverpool, UK, discusses the current status in non-small cell lung cancer (NSCLC) of PD-L1 as a biomarker, which shows expression variation in primary tumors vs. nodal metastases, and often requires a companion biomarker. Dr Haragan then goes on to discuss our knowledge of tumor mutational burden (TMB) as a biomarker in NSCLC.
