Impact of a pathologist-driven molecular testing protocol on veterans with non-small cell lung cancer.

Abstract

e21209 Background: Precision medicine has shifted the paradigm of cancer treatment in the last two decades. Currently, with over ten targetable mutations in non-small cell lung cancer (NSCLC) and increasingly emerging biomarkers for immunotherapy, genomic testing is necessary for every NSCLC patient. However, this multiple biomarker-defined treatment approach is often compromised by many challenges including slow turnaround time (TAT), high rate of quantity not sufficient (QNS) resulting in inaccurate molecular testing or needs for second biopsy. These barriers lead to increased risk of developing medical complications from re-biopsy or treatment delay as well as additional social and financial support, which is not always available for veterans. A recent study reported that up a one third of veterans with NSCLC containing highly actionable mutations were not prescribed targeted treatment, among which, 25% of patients do not have a documented molecular testing results. Herein, we reported a pathologist-driven protocol to enhance the implement of molecular testing on guiding NSCLC treatment in veteran population. Methods: A pathologist-driven molecular testing protocol is applied West Los Angeles VA hospital since 2018. First, in preparation for diagnosis and molecular testing, tissue block will be cut in serial sections in the following priority: 2 slides for H&E, 4 slides for IHC, 2 slides for PD-L1 staining. An additional slide is made for quality control (QC) purpose before 10 additional slides are cut for molecular testing and 6 for FISH studies. The reminder of the tissue block will be cut in serial sections and preserved in a vial along with tissue shaved at initial block effacement. Every tissue block will be exhausted. Upon initial evaluation of H&E slides, the reviewing pathologist, independent of the treating oncologist, will order molecular testing including EGFR, ALK, ROS and BRAF by NGS if NSCLC is identified. PD-L1 IHC staining is also ordered automatically regardless of the histology. If a clinically actionable mutation is detected, a mutation notification is immediately sent via email by the molecular pathologist to alert the treating oncologist. Results: After implementing this protocol, we observed a decreased rate of QNS (~30% reduction) and subsequently the need for 2ndbiopsy dropped substantially. We also observed a faster TAT between initial cancer diagnosis (within 7 days) and the resulting of molecular testing to guide subsequent treatment. Conclusions: Refined tissue processing and pathologist driven ordering system can significantly impact initial management of patients with NSCLC as it reduces the rate of QNS and repeat biopsy/TAT. This protocol can be easily implemented in VA system or other community based healthcare system.