Question

Liquid biopsy, its principle and its application.

Hint:

Liquid biopsy is a promising tool for non-invasive cancer diagnosis, monitoring, and personalized treatment plans. Its ability to detect genetic alterations in tumor-related materials is revolutionary.

Answer 1

Liquid biopsy is a non-invasive method of detecting and analyzing genetic material, tumor cells, or biomarkers from body fluids, such as blood, urine, or saliva. It is increasingly used in cancer diagnosis, monitoring treatment response, and detecting minimal residual disease.
Step 1: Principle of Liquid Biopsy:
1. Detection of Circulating Tumor DNA (ctDN: Liquid biopsy primarily involves the detection of ctDNA, which is released into the bloodstream by tumor cells. This DNA carries genetic mutations and alterations that are specific to the tumor.
2. Circulating Tumor Cells (CTCs): Another target is CTCs, which are tumor cells shed into the bloodstream. Their presence can provide valuable information about tumor metastasis.
3. Exosomes and MicroRNAs: Liquid biopsy can also detect exosomes and microRNAs, which are small vesicles and RNA molecules secreted by tumors. These contain tumor-related biomarkers that can be analyzed to understand the tumor’s characteristics.
Step 2: Applications of Liquid Biopsy:
1. Early Detection of Cancer: Liquid biopsy is used for the early detection of various cancers by identifying genetic mutations and biomarkers associated with specific cancers.
2. Monitoring Treatment Response: It helps in monitoring how well a patient is responding to treatment by analyzing changes in ctDNA and CTC levels over time.
3. Minimal Residual Disease Detection: Liquid biopsy is also used to detect minimal residual disease after treatment, which can help in identifying patients at high risk of relapse.