Early stage detection of cancer is essential for the improved long-term survival of patients. Currently, costly, extensively complex and invasive procedures, such as surgical tissue biopsies, are used for cancer screening. Thus, over the past few decades, advancements in microfluidics and lab-on-a-chip approaches have been made to develop minimally invasive and miniaturized platforms to identify and segregate circulating cancer biomarkers such as exosomes, circulating tumor cells (CTCs) and cell-free DNA (cfDNA) from body fluids. Our study presents a comprehensive overview of all such microfluidics based approaches for point-of-care cancer diagnostics, which have proven to require significantly reduced sample volumes with cost effective and minimally invasive criteria. We have also discussed the need for integrated and more efficient devices to further advance these technologies to be suitable for liquid biopsy in the clinical settings.