Personalized Approach to Tissue and Liquid Biopsy after Failure of First-Line EGFR-TKIs: Is There an Issue When Tissue Is Not the Issue? A Case Series

Abstract

Traditionally, tissue availability from rebiopsy is a prerequisite for adequate sequencing of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in therapy for advanced-stage lung cancer. Tissue biopsy truly is the gold standard for genetic analyses, but in some cases, such as with inadequate localization of the lesion or a patient’s inadequate performance status, comorbidities, or unwillingness to undergo an invasive procedure, liquid biopsy-based ctDNA analysis can be a noninvasive alternative approach. However, in some cases the gold standard might not shine that much. It is known that tumor heterogeneity or an inadequate amount of tissue might significantly interfere with the results of testing. In this paper, we present cases of patients with a negative tissue biopsy but a positive liquid biopsy which identified coexisting T790M mutation. These results enabled adequate sequencing and treatment with third-line EGFR-TKIs. Such possibilities stress the need to individualize testing for driver mutations in cases where it is clinically highly indicated.

Cryobiopsy for pneumonitis diagnosis in NSCLC immunotherapy

“…Non-small cell lung cancer is still diagnosed at advanced stage and systemic treatment administration is required. We have nowadays novel tools for the diagnosis and staging of lung cancer like radial-ebus, electromagnetic navigation and convex probe-ebus [ [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] ]. However; we still need a successful lung cancer screening program for early lung cancer diagnosis [ 9 ].…”

“…However; we still need a successful lung cancer screening program for early lung cancer diagnosis [ 9 ]. Since most patients are diagnosed at advanced stage we have several different therapies for non-small cell lung cancer like (NSCLC) like chemotherapy, tyrosine kinase inhibitors, radiotherapy, immunotherapy or combination of those treatment modalities [ [10] , [11] , [12] , [13] , [14] , [15] ]. Immunotherapy is considered nowadays the tip of the arrow for non-small cell lung cancer and it can be administered alone when the programmed death-ligand 1 (PD-L1) is ≥ 50% or in combination with chemotherapy when the PD-L1 expression is ≤ 50%.…”