ABSTRACT
Liquid biopsy is rapidly becoming an indispensable tool in the oncologist's arsenal; however, this technique remains elusive in a publicly funded healthcare system, and real-world evidence is needed to demonstrate utility and feasibility. Here, we describe the first experience of an in-house point of care liquid biopsy program at a Canadian community hospital. A retrospective review of consecutive cases that underwent plasma-based next-generation sequencing (NGS) was conducted. Liquid biopsy was initiated at the discretion of clinicians. Sequencing followed a point of care workflow using the Genexus™ integrated sequencer and the Oncomine precision assay, performed by histotechnologists. Results were reported by the attending pathologist. Eligible charts were reviewed for outcomes of interest, including the intent of the liquid biopsy, results of the liquid biopsy, and turnaround time from blood draw to results available. A total of 124 cases, with confirmed or suspected cancer, underwent liquid biopsy between January 2021 and November 2023. The median turnaround time for liquid biopsy results was 3 business days (range 1-12 days). The sensitivity of liquid biopsies was 71%, compared to tissue testing in cases with matched tissue results available for comparison. Common mutations included EGFR (29%), in 86 lung cancer patients, and PIK3CA (22%), identified in 13 breast cancer patients. Healthcare providers ordered liquid biopsies to inform diagnostic investigations and treatment decisions, and to determine progression or resistance mechanisms, as these reasons often overlapped. This study demonstrates that rapid in-house liquid biopsy using point of care methodology is feasible. The technique facilitates precision treatment and offers many additional advantages for cancer care.
ABSTRACT
Purpose: We first described the role of local radiation therapy (LT) for oligoprogressive disease (OPD) on targeted therapy in 2012. Here, we present an updated and larger data set and extend the analysis beyond EGFR and ALK. Methods: A retrospective review of patients with metastatic NSCLC harboring EGFR/BRAF V600E mutations, or ALK/ROS1/RET rearrangements, who had OPD on respective tyrosine-kinase inhibitor (TKI) and treated with LT was performed. OPD was defined as disease progression on therapy in ≤5 sites. PFS1 (progression-free survival 1) was defined as time from initiation of TKI-containing regimen to the first course of LT for OPD. Subsequent PFS times (eg, PFS2, PFS3) were defined as time from prior LT to subsequent LT, switch of systemic therapy, death, or loss to follow-up, whichever occurred first. Extended-PFS was defined as time from the first day of the first LT course to the day of change in systemic therapy, death, or loss to follow-up, whichever came first. Results: Eighty-nine patients were identified. In 75.4% of the LT courses, a single lesion was treated. Median PFS1 was 10.2 months (95% CI, 8.7-13.1) and median Extended-PFS was 6.7 months (95% CI, 4.9-8.3). Extended-PFS was similar across different oncogenic drivers; 51.4% of patients who underwent LT to a single site had only 1 site on next disease progression. Conclusions: LT is effective in prolonging treatment duration on TKI in oncogene-addicted NSCLC across multiple oncogenes.