A systematic review on liquid biopsy for cancer diagnosis: basis for identifying gaps and areas for progress and development

Abstract

Liquid biopsy is a minimally invasive procedure that utilizes body fluids, primarily blood, and allows for the early detection of cancer. This study utilized a meta-analysis in order to evaluate the diagnostic values of liquid biopsy using cfDNA, CTCs, and ctDNA as molecular biomarkers in detecting liver, lung, and colorectal cancer – the three most common cancers in the Philippines. A meta-analysis was performed using articles obtained from NLM, PubMed, Medline databases, Web of Science, ResearchGate and Google Scholar. Based on the included studies, CTCs had the highest sensitivity, while both ctDNA and CTCs had the highest specificity. The pooled sensitivity and specificity for overall liquid biopsy were 0.83 (95%C 0.82-0.85) and 0.93 (95%CI 0.93-0.94), respectively. Overall liquid biopsy had a PLR, NLR and DOR of 15.38 (95% 10.43-22.68), 0.21 (95% 0.18-0.025), and 95.98 (95% 55.91-164.75), respectively and suggest no statistical significance with the values obtained from the gold standard. Bioinformatics techniques were used to create primers and protein models for AFP, KRAS and SEPT9. All 8 designed primers proved to be efficient due to the promising specificity properties that were collected from the designed primers and the properties that were present from the published primers. The KRAS mutations exhibited the substitution of glutamine to histidine and suggest interference with GTP hydrolysis, while the mutations in SEPT9 contained deletions and substitutions and suggest interference with cell division. AFP mutations exhibited deletions; however, further research is required to determine how tehse mutations alter the normal function of the gene.