High tumor burden in non-small-cell lung cancer: A review of the literature.

Background and Aim: Lung cancer is the leading cause of cancer death worldwide and the majority of the patients have advanced/metastatic disease on presentation. In clinical practice, several biomarkers and clinical factors are taken into account when choosing the best treatment option in advanced non-small-cell lung cancer (NSCLC). One potential marker may be tumor burden (TB). However, this concept is not specifically defined in NSCLC, and usually, it is used as a synonymous for aggressive disease. Methods: A non-systematic literature review was conducted. We searched for eligible randomized controlled trials from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials with a cutoff at February 2021. The keywords included non-small-cell lung cancer, tumor burden, aggressive disease, prognosis biomarker, predictive biomarker, and immunotherapy. Results and Conclusions: This review addresses the definition of TB in advanced NSCLC, the pathophysiology of high TB lesions, and the role of TB as a prognosis biomarker. Relevance for Patients: The concept of aggressive disease, as high tumor burden definition, remains poorly defined and rarely considered in clinical research or clinical practice in oncology. The identification of this subgroup of patients could be interesting for defining and optimizing a more aggressive treatment strategy.