Liquid biopsy edges closer to routine use in cancer diagnostic workups. Yet, a number of barriers exist to its full adoption in clinical practice. A July 31 afternoon short course at the 69th AACC Annual Scientific Meeting & Clinical Lab Expo, Liquid Biopsy As An Emerging Noninvasive Clinical Tool for Cancer Patient Management (72217), will describe the pre-analytical, technical, and bioinformatic challenges facing this technology.
Rajyalakshmi Luthra, PhD, director of the molecular diagnostic laboratory at the University of Texas MD Anderson Cancer Center in Houston, offered factors that have prevented liquid biopsy adoption, including: interlaboratory standardization of pre-analytical parameters (collection device and processing procedures) and analytical assay performance characteristics (library preparation procedures and bioinformatic analysis pipeline).
“Post-analytical parameters such as definition of positive signal and normal reference ranges are also critical for nationwide implementation of liquid biopsy in clinical practice,” said Luthra, who plans to discuss the pre-analytical and analytical considerations of liquid biopsy (circulating tumor DNA) in assay development and validation.
Luthra’s colleague at MD Anderson, Qing Meng, MD, PhD, section chief of clinical chemistry laboratories, will address new technology in cancer therapy to detect circulating tumor cells. “Liquid biopsies have the potential to allow physicians to quickly identify patients who have specific mutations potentially suitable for targeted therapy,” Meng said. Liquid biopsy testing has been approved by the Food and Drug Administration for only a few epidermal growth factor receptor mutations, however.
A number of potentially targetable mutations are still pending for approval, which should facilitate clinical applications and meet clinical needs, he said.
In the meantime, the introduction of laboratory developed tests (LDTs) by individual laboratories may be able to fill the gaps as far as clinical needs are concerned and improve cancer patient care quality and outcomes, Meng added.
Dana Tsui, PhD, faculty member of the Marie-Josée and Henry R. Kravis Center for Molecular Oncology and department of pathology at Memorial Sloan Kettering Cancer Center (MSKCC) in New York City rounds out the panel with her talk on molecular profiling, from tumors to blood.
Both MD Anderson and MSKCC have taken steps to centralize procedures and foster collaboration to effectively use liquid biopsy in clinical practice.
Clinicians at MD Anderson have addressed pre-analytical challenges by standardizing blood collection procedures, Luthra said. This involves using liquid biopsy-suitable blood drawing tubes at collection centers in the hospital, and standardizing plasma separation and nucleic acid isolation in the Clinical Laboratory Improvement Amendments (CLIA)-certified and College of American Pathologists-accredited molecular diagnostic laboratory.
“Similarly, analytical and post-analytical challenges, including sensitivity and specificity of clinical liquid biopsy assays, are addressed by working closely with clinicians in specific disease centers,” Luthra said.
At MSKCC, most plasma samples are collected and processed in a central CLIA laboratory. The analytical workflow, developed as a collaboration between MSKCC’s Center for Molecular Pathology and MD Anderson’s Molecular Diagnostic Pathology laboratories, ensures consistency in standard operating procedures and bioinformatics analysis, according to Luthra and Tsui. To guide treatment decisions, the clinical lab at both institutions collaborates with a disease team to reach consensus on the definition of clinical thresholds.
“Future success for liquid biopsy in clinical practice relies on partnerships between academic, industry, and regulatory institutions,” Luthra said.
To get the inside track on the future of liquid biopsy at this afternoon short course, worth 1.5 CE credits, register for the 69th AACC Annual Scientific Meeting & Clinical Lab Expo June 30–Aug. 3 in San Diego.