Higher Tumor Mutation Burden and Higher PD-L1 Activity Predicts the Efficacy of Immune Checkpoint Inhibitor Treatment in a Patient With Four Lung Cancers. A Case Report

Pulmonary pleomorphic carcinoma: current understanding illustrated through a case

This article describes a case of a man in his early 40s who was diagnosed with pulmonary pleomorphic carcinoma (PPC). PPCs are rare and aggressive forms of lung cancer. Chemotherapy is of limited efficacy. We present a case that has seemingly recurred shortly after adjuvant chemotherapy and immunotherapy following an R0 resection for localised disease. Biopsy however was negative for recurrence. PPCs may bear actionable mutations and tyrosine kinase inhibitors may be used when appropriate. Immunotherapy with or without chemotherapy is emerging as the mainstay for metastatic disease despite a lack of evidence from randomised clinical trials.

Microsatellite Instability, Mismatch Repair, and Tumor Mutation Burden in Lung Cancer

Since US Food and Drug Administration approval of programmed death ligand 1 (PD-L1) as the first companion diagnostic for immune checkpoint inhibitors (ICIs) in non-small cell lung cancer, many patients have experienced increased overall survival. To improve selection of ICI responders versus nonresponders, microsatellite instability/mismatch repair deficiency (MSI/MMR) and tumor mutation burden (TMB) came into play. Clinical data show PD-L1, MSI/MMR, and TMB are independent predictive immunotherapy biomarkers. Harmonization of testing methodologies, optimization of assay design, and results analysis are ongoing. Future algorithms to determine immunotherapy eligibility might involve complementary use of current and novel biomarkers. Artificial intelligence could facilitate algorithm implementation to convert complex genetic data into recommendations for specific ICIs.