# Evaluating the Utility and Implementation Barriers of a Liquid Biopsy Biomarker Test Early in the Lung Cancer Diagnostic Pathway to Improve Timeliness of Palliative Systemic Therapy

## TL;DR

A blood test for lung cancer biomarkers was studied to speed up treatment, but delays in reporting results were found due to lab practices and supply issues.

## Contribution

Identified implementation barriers of liquid biopsy in accelerating lung cancer treatment timelines.

## Key findings

- Liquid biopsy blood draws occurred 11 days earlier than tissue biopsies, but results took 78 days versus 22 days for tissue.
- Delays in liquid biopsy reporting were due to batching samples and pandemic-related supply chain issues.
- Liquid biopsy showed good reliability in biomarker detection compared to tissue biopsy.

## Abstract

This study attempted to determine whether a blood test (known as a liquid biopsy) could help shorten the time for lung cancer patients to receive biomarker results and start treatment compared with a traditional solid tissue biopsy. We studied 324 patients undergoing evaluation for lung cancer and found that while the blood test was performed an average of 11 days earlier than the tissue biopsy, the test results took much longer to be reported (78 vs. 22 days). These delays were not due to the test itself, but rather due to laboratory factors, such as needing to batch the samples to run the analysis economically rather than analyzing them individually upon receipt, as well as factors related to pandemic supply shortages. Despite these barriers, our study also demonstrated good reliability of liquid biopsy in revealing the same biomarker results compared with the standard tissue biopsy, such that it would be important to further explore the utility of liquid biopsy in improving the timeliness of lung cancer care while addressing identified laboratory barriers.

Purpose: Timeliness of systemic therapy initiation for advanced lung cancer is highly dependent on pathology and molecular pathology laboratory services. Here, we aimed to prospectively evaluate liquid biopsy as a potential strategy to expedite systemic therapy decision-making in lung cancer management. Patients and Methods: This prospective cohort study included consecutive patients with suspected lung cancer seen at the time of initial specialist consultation who underwent both liquid and solid tumour biopsy (group A) and patients with confirmed lung malignancy who underwent solid tumour biopsy alone (group B), between 1 February 2022 and 31 May 2023. Due to laboratory factors, liquid biopsies were processed in batches of 13, whereas solid tumour biopsies were processed individually upon receipt, as per standard practices. Co-primary endpoints included the time from solid versus liquid biopsies to biomarker reporting and palliative systemic therapy initiation. Results: A total of 324 patients were included in the study. The median time from date of blood draw to date of liquid biopsy result was 78 days. For group A (n = 50), the median time from date of solid tumour biopsy to biomarker reporting was 22 days, and the median time from date of solid tumour biopsy to palliative systemic therapy was 42 days. The median time from date of liquid biopsy blood draw to palliative systemic therapy initiation was 56 days. For group B (n = 274), the median times from date of biopsy to biomarker reporting and to palliative systemic therapy initiation in all patients were 22 and 47 days, respectively. Conclusions: While we did not demonstrate improvement in timeliness of biomarker reporting or systemic therapy initiation with liquid biopsy, several barriers leading to delay in liquid biopsy reporting were identified due to unexpected COVID-19-related supply chain disruption and the cost-limiting need to batch sample analysis. Further studies that address the identified barriers are warranted to assess the potential improvement in timeliness of care, should liquid biopsy analysis be implemented in real-time.