Higuera Gómez O, Moreno Paul A, Ortega Granados AL, et al. - For clinical decision-making as well as treatment selection in metastatic non-small cell lung cancer (mNSCLC), detecting patient features that describe a worse disease prognosis or “high tumor burden” (HTB) status is important, therefore, researchers herein intended to describe this concept based on the experience of oncologists in clinical practice. Oncologists (N = 81) found HTB as one of the principal factors impacting first-line treatment decision-making. About half of respondents (n = 33, 41%) admitted that one metastatic lesion was sufficient to consider a patient as presenting HTB, 72% (n = 58) considered that two were mandatory and 99% (n = 80) three. The main metastatic sites related to HTB included liver (n = 76, 100%) followed by brain (n = 65, 86%). As per experts, the number of metastatic lesions, location of metastases, tumor size and high lactate dehydrogenase levels were the factors that defined HTB in the real-world setting. Since this concept is relevant, making attempts to unify its definition as well as further investigating its potential as a prognostic factor for mNSCLC cases, is recommended.