Introduction
A liquid biopsy is a diagnostic procedure that involves analyzing a sample of bodily fluid, such as blood or urine, to detect and analyze genetic material or other biomarkers associated with hematological cancer or conditions.
What Is Liquid Biopsy?
A liquid biopsy is a diagnostic procedure that utilizes a blood sample to identify malignant tumors. As a tumor expands, fragments might detach and circulate within the bloodstream. A liquid biopsy can detect and identify such fragments. Liquid biopsies can identify:
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Circulating tumor cells (CTCs) are cancer cells detached from the primary tumor and circulating in the bloodstream.
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Circulating tumor DNA (ctDNA) refers to fragmented DNA derived from tumor cells in the bloodstream. DNA comprises the genetic code, which serves as the instructions governing a cell's behavior.
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Circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) present in the bloodstream indicate the presence of a malignant tumor. The tumor fragments also yield genetic data about the malignancy, which can assist the healthcare professional in determining the most effective treatments.
Liquid biopsy is an emerging diagnostic test with the potential to revolutionize cancer treatment. Research is ongoing to explore its advantages.
What Distinguishes a Liquid Biopsy From a Traditional Biopsy?
Liquid biopsies differ from traditional biopsies because they do not directly analyze tumor tissue. Alternatively, they conduct tests to detect signs of malignancy. A biopsy is the extraction of a tissue sample from a tumor by a healthcare professional. This procedure aims to examine the cells in a laboratory setting to determine if they are cancerous. On the other hand, a liquid biopsy identifies indications of a tumor, such as tumor cells and tumor DNA.
A biopsy is often regarded as the most reliable and accurate method for identifying cancer. This treatment is the most effective method currently available for diagnosing cancer. A liquid biopsy cannot provide a definite assurance of detecting indications of a tumor in a single blood sample, even if a tumor is present. However, liquid biopsies offer crucial insights into cancer cells, aiding healthcare providers in treatment planning.
What Are the Various Applications of Hematological Malignancy?
1. The Screening Process: Blood tests for cancer screening and surveillance are not new. These earlier methods can provide high false positive rates and excessive nonspecificity.
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Tumors release CTCs and cfDNA into the circulation, making liquid biopsies a possible cancer screening tool. Indeed, laboratories worldwide are competing to develop blood-based screening techniques.
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To screen for cancer, liquid biopsy analysis must be able to detect when the tumor is actively secreting cancer cells. Cancer progression from in situ to invasive could be linked to innate immune activation. Such modifications may be detected in the bloodstream before imaging.
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Tumor metabolism byproducts may be another way to diagnose cancer. Many years remain before liquid biopsies are used for cancer screening and diagnosis. However, actionable mutation detection for patient classification, medication resistance surveillance, and therapy selection has advanced.
2. Therapeutic Mutation Identification
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The amount of evidence suggests that cfDNA is a versatile, sensitive, and specific biomarker for clinical and research use in patients with various cancers.
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Liquid biopsies may replace tumor molecular profiling, which identifies actionable mutations that may affect therapy selection in patients who cannot have a tissue biopsy or need an adjunct.
3. For Illness Prognosis
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Genes such as CTCs and cfDNA can help predict disease prognosis. In addition to cfDNA mutations, the quantity of CTCs at baseline and throughout treatment can predict clinical outcomes.
4. Drug Resistance and Reaction
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CTCs and cfDNA can predict drug resistance and response in targeted treatment patients. Serial blood samples for cfDNA analysis are a major benefit of liquid biopsies. This allows the investigation of molecular alterations during therapy, which may help detect drug resistance before radiographic disease development.
What Are the Future Aspects of Liquid Biopsy?
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Fluid Phase Biopsy With Minimal Invasiveness: Fluid biopsy, sometimes called fluid phase biopsy, is a minimally invasive or non-invasive method. A patient's biological fluids, such as blood, urine, cerebrospinal fluid, and stool samples, are obtained to diagnose cancer. Cancer patients experience difficulty with tissue biopsy, the traditional way of detecting the disease, as it is intrusive, unpleasant, and necessitates anesthesia. Tissue biopsies can occasionally result in unpleasant consequences and a hospital stay.
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Cancer Analysis: Liquid biopsy enhances early identification, prognosis, treatment response monitoring, and information concerning established resistance by providing real-time access to the genetic characteristics of particular tumors. When a tissue biopsy is sampled, information regarding the tumor at the moment of surgery is static and confined in space. On the other hand, cancer is constantly changing between its primary and advanced stages due to genetic variability.
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Preservation of the Sample Without Degradation: A sample from a liquid biopsy is simple to remove and maintain for a precise diagnosis. No chemicals of any type have been added, which would lower the sample efficiency for molecular analysis. Although a sample is typically kept in formalin and paraffin for regular pathology in tissue biopsies, this can also limit the sample's usefulness for sophisticated molecular research.
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Potential Biomarkers for Medical Diagnosis: Biomarkers found in biological fluids have been the foundation of liquid biopsy analysis for detecting and treating cancer. Tumor-educated platelets (TEPs), exosomes, circulating tumor cells (CTCs), cell-free DNA (cfDNA), circulating tumor DNA (ctDNA), proteins, and metabolites are the primary biomarkers. Most of them have short half-lives, which allows them to identify cancer patients in real-time. They are employed as treatment-resistant emerging markers and biomarkers for diagnostic testing.
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Beneficial for Customized Medicine: Throughout cancer treatment, samples are easier to get, and liquid biopsy is used to analyze the samples since it is less intrusive. It is easily repeatable and useful for tracking patients' responses to therapy during and after treatment to move toward customized medications.
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Identification of Medication Resistance and Cancer Recurrence: Liquid biopsy offers information on molecular alterations in the tumor both before and after therapy, which makes it a promising tool for tracking the emergence of drug resistance and offering a treatment option. Additionally, it can be used to track the advancement of cancer and serve as a monitoring technique for cancer patients who have finished their treatment but are more likely to experience a relapse.
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Simple Sampling Process: Liquid biopsy sampling is straightforward, regardless of the patient's state or the tumor's location. The patient's health and the tumor's location may make tissue biopsy sampling difficult.
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Identification of Heterogeneity Within Tumors: Since tissue biopsy cannot determine the tumor's mutational state, liquid biopsy plays a useful role in discovering intra-tumor heterogeneity.
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Identification of MRD and Treatment Option Selection: Using liquid biopsy to diagnose MRD using blood analytes is essential since this could aid in selecting treatment plans for MRD patients. When combined with NGS methods, liquid biopsies offer extremely sensitive minimal residual disease (MRD) diagnosis in cancer. Liquid biopsy makes it possible to assess whether treatment de-escalation is safe for MRD-negative patients and whether treatment escalation improves cancer outcomes in MRD-positive patients.
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Precision Medicine: The development of genome sequencing techniques has made it much simpler, faster, and less expensive to obtain complete genetic information about cancers, making therapy monitoring and detection easier. Using such genetic profiles in precision medicine for cancer patients is very likely to occur.
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Early Cancer Detection: Cancer mortality may be decreased if the disease can be identified in its early stages. Tissue biopsy is still the gold standard for solid tumor cancer diagnosis. However, its use is restricted to early detection of malignancies without symptoms. Liquid biopsies are vital to the prevention and treatment of cancer since they are primarily used to collect data on tumors to identify cancer in its early stages.
Conclusion
As companion diagnostics, liquid biopsy analysis can reveal invasive biology and improve therapy categorization and cancer cell selection. Targeted therapy may avoid clearing all tumor clones due to intra-patient tumor heterogeneity. For years, researchers and doctors have recognized liquid biopsies have clinical potential. More interventional clinical trials and an algorithm are needed to aggregate circulating biomarkers and spread them. Future liquid biopsies will examine complex cancer data and require more AI and machine learning.
Most hematological malignancy liquid biopsy studies evaluated gene mutations. When paired with new statistical and machine learning technologies, liquid biopsy may also analyze copy number aberrations, fragmentomics, and epigenetic patterns of ctDNA, which may improve hematological disease molecular characterization.
