From photonic technologies to microfluidics-A review on the techniques which revolutionize liquid biopsy, opening a new era in cancer therapy.

Background And Aims: Cancer therapy is one of the most researched upon medical field in the world. Non invasive technologies such as liquid biopsy are gaining more importance in cancer therapy because of their manifold advantages over traditional invasive biopsy methods. Liquid biopsy is used to analyze nucleic acids such as ctDNA, cfDNA and RNA, cellular and subcellular components such as proteins, extracellular vesicles and circulating tumor cells in various biological fluids such as blood, urine, cerebrospinal fluid, pleural fluid and ascites fluid for diagnosis of cancer.

Methods: Liquid biopsy has a wide range of applications such as assessment of residual diseases and tumors which cannot be biopsied easily and prediction of CAR-T response and response to immune checkpoint inhibitors. It can also be used to know the efficacy of cancer drugs in a patient by analyzing multiple samples. Liquid biopsy is becoming more popular as it allows biopsy of those samples in which solid tumor biopsies are challenging or impracticable.

Techniques And Results: To achieve comprehensive insight on the status of cancer in a patient, various cutting edge liquid biopsy techniques have been developed. Microfluidics and photonic technologies, along with PCR, next generation sequencing, advanced and innovative molecular and cell biology approaches and imaging techniques have expanded the domain of liquid biopsy and elevated the accuracy of liquid biopsy results.

Conclusion: This review discusses about the contributions of some widely used methods along with microfluidics and photonic technologies in detection of cancer biomarkers by liquid biopsy.