Abstract
The proportion of cancer patients with tumours that harbour a potentially targetable genomic alteration is growing considerably. The diagnosis of these genomic alterations can lead to tailored treatment at the onset of disease or on progression and to obtaining additional predictive information on immunotherapy efficacy. However, in up to 25% of cases, the initial tissue biopsy is inadequate for precision oncology and, in many cases, tumour genomic profiling at progression is not possible due to technical limitations of obtaining new tumour tissue specimens. Efficient diagnostic alternatives are therefore required for molecular stratification, which includes liquid biopsy. This technique enables the evaluation of the tumour genomic profile dynamically and captures intra-patient genomic heterogeneity as well. To date, there are several diagnostic techniques available for use in liquid biopsy, each one of them with different precision and performance levels. The objective of this consensus statement of the Spanish Society of Pathology and the Spanish Society of Medical Oncology is to evaluate the viability and effectiveness of the different methodological approaches in liquid biopsy in cancer patients and the potential application of this method to current clinical practice. The experts contributing to this consensus statement agree that, according to current evidence, liquid biopsy is an acceptable alternative to tumour tissue biopsy for the study of biomarkers in various clinical settings. It is therefore important to standardise pre-analytical and analytical procedures, to ensure reproducibility and generate structured and accessible clinical reports. It is essential to appoint multidisciplinary tumour molecular boards to oversee these processes and to enable the most suitable therapeutic decisions for each patient according to the genomic profile.
Highlights
By the year 2030, 22.2 million new cases of cancer are expected worldwide: a challenge for cancer patient diagnosis and therapeutic approaches
The feasibility of liquid biopsy depends on the amount of detected circulating tumour DNA (ctDNA), different factors such as the amount and site of metastases, the cell proliferation index, the apoptosis rate, the genomic instability or the amplification of a gene associated with a mutation can be limiting factors [45, 77]
It is important that the results reported from the ctDNA test are precise and clear so that the necessary information for therapeutic decision making is transmitted
Summary
By the year 2030, 22.2 million new cases of cancer are expected worldwide: a challenge for cancer patient diagnosis and therapeutic approaches. AS-PCR is frequently used in clinical practice to detect single nucleotide variants or small insertions/ deletions in paraffin-fixed tissue It has 98% specificity and 92% sensitivity with 96% concordance with the mutant allele in ctDNA samples [23], it is not the most adequate qPCR type for liquid biopsy. The feasibility of liquid biopsy depends on the amount of detected ctDNA, different factors such as the amount and site of metastases (except in patients with metastatic brain disease), the cell proliferation index, the apoptosis rate, the genomic instability or the amplification of a gene associated with a mutation can be limiting factors [45, 77]. There are several providers or associations for validating the technique: European Molecular Genetics Quality Network (EMQN), European Society of Pathology (ESP), EQA and the United Kingdom National External Quality Assessment Service (UK NEQAS) for Molecular Genetics, sponsored by the International Network for Pathology (IQN Path) [96, 97]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
