Clinical Benefit and Agenda for Clinical Sequencing Using Cancer Panel Testing: A Retrospective Clinical Study

Background: Clinical sequencing using a multiplex gene panel has recently been applied worldwide for patients with refractory solid tumors, but the significance of clinical sequencing using multiplex gene panel testing remains uncertain. Here we sought to clarify the feasibility and utility of clinical sequencing in the treatment of refractory tumors at our hospitalMethods: A total of 28 patients with advanced solid tumors treated at our hospital between 2018 and 2020 were enrolled in the clinical sequencing. Among them, we identified 26 patients whose tissue samples were of suitable quality for clinical sequencing, and we analyzed the genomic profiles of these tumors.Results: Pathogenic alterations were detected in 20 (77%) of the 26 patients. The most common mutation was TP53 (6/26, 35%), followed by KRAS (5/26, 19%), and the highest frequency of gene amplification was ERBB2 (5/26, 19%). Five of the 26 patients were identified as candidates for novel molecular-targeted therapy based on their actionable gene alterations, but none of the cases had an advantage for novel targeted therapy following the genetic tests; the reasons were clinical deterioration, refusal for off-label use, and complexity of clinical trial access.Conclusions: Our current results suggested that clinical sequencing might be useful for the detection of pathogenic alterations and the management of additional cancer treatment. Both improved optimal timing of clinical sequencing and a consensus about its off-label use might help patients receive greater benefit from clinical sequencing.Trial registration: This study was performed as a part of clinical study approved by Ethical Committee of Osaka City University Graduate School of Medicine (Permission number: 4199, 3925)