Liquid biopsy is a blood-based cancer test that detects tumor DNA circulating in the bloodstream
It is a non-invasive alternative to traditional tissue biopsy for cancer detection and monitoring
Liquid biopsy is widely used for treatment response monitoring and detecting resistance mutations
Its accuracy varies by cancer stage, with better performance in advanced disease than early detection
Liquid biopsy tests are increasingly available in India, driven by advances in genomic diagnostics and precision oncology
Can cancer be detected through a simple blood test?
Cancer diagnosis has long depended on imaging and tissue biopsy. These methods remain essential, yet they often detect disease after it has progressed and may require invasive procedures. A growing area of oncology is now exploring whether cancer can be identified through a simple blood test.
Liquid biopsy is built on this idea. By analyzing tumor-derived material circulating in blood, it offers a minimally invasive way to study cancer biology. This approach to cancer detection through blood is gaining attention as a potential blood-based cancer detection strategy. The concept is scientifically grounded, but its clinical role is still being defined through ongoing research.
Tissue biopsy is still the diagnostic gold standard because it allows direct histological and molecular evaluation. However, several limitations are well recognized:
It is invasive and may not always be feasible due to tumor location
It captures only a portion of the tumor, which may not reflect its genetic diversity
Repeated sampling is difficult, especially in advanced disease
Imaging methods such as CT and PET scans provide structural information but lack molecular detail. Tissue biopsy provides histology and tumor architecture, whereas liquid biopsy provides dynamic molecular information that can change over time.¹
Liquid biopsy refers to a non-invasive cancer test that detects tumor-associated material in body fluids, most commonly blood. It relies on the principle that tumors release measurable components into circulation, making blood test for cancer detection possible in certain clinical contexts.
Key analytes include:
Circulating tumor DNA (ctDNA), often assessed through a ctDNA test
Cell-free DNA (cfDNA)
Circulating tumor cells (CTCs)
Extracellular vesicles such as exosomes
Tumor-educated platelets and RNA signatures
These biomarkers represent tumor DNA in blood and can provide insights into tumor genetics, including mutations, epigenetic changes, and gene expression patterns.²
Tumors undergo continuous cell turnover, releasing DNA fragments and cells into the bloodstream. Liquid biopsy captures and analyzes this material using advanced molecular techniques.
Peripheral blood collection
Plasma separation and extraction of cfDNA or isolation of CTCs
Molecular analysis using PCR, digital PCR, BEAMing (beads, emulsion, amplification, magnetics), or next-generation sequencing
Identification of tumor-specific alterations such as mutations, copy number changes, or methylation patterns
Detection depends on the tumor fraction, which refers to the proportion of tumor-derived DNA within total circulating cell-free DNA. This fraction is often very low in early-stage cancers, which directly affects test sensitivity and specificity.³
Recent advances include ultra-deep sequencing and methylation-based assays, which improve detection sensitivity, particularly in early-stage disease. DNA methylation patterns are also being explored to identify the tissue of origin in multi-cancer early detection tests, supporting research into early cancer detection blood tests.³
Liquid biopsy has established roles in several clinical scenarios, especially in advanced cancers.
Serial measurement of ctDNA levels can function as a cancer monitoring blood test, reflecting tumor burden and response to therapy, sometimes earlier than radiological changes.⁴
Serial liquid biopsies enable tracking of tumor evolution over time.
After surgery or chemotherapy, small amounts of residual cancer may persist. Liquid biopsy can help detect this minimal residual disease and predict relapse.⁵
In lung cancer, liquid biopsy is widely used to detect mutations such as EGFR T790M, which guide targeted therapy decisions.⁶
In some patients, obtaining a tissue biopsy is not feasible. Liquid biopsy supports genomic profiling in cancer by providing molecular insights when tissue samples are limited.⁷
Research is ongoing into multi-cancer early detection tests using ctDNA and methylation signatures, although these are not yet standard clinical tools.⁸
Performance is generally better in advanced cancers such as lung, colorectal, and metastatic disease.
Some liquid biopsy assays are approved or recommended in specific clinical contexts, particularly for detecting actionable mutations in advanced cancers when tissue samples are unavailable or insufficient.⁷
Liquid biopsy can also provide results faster than repeat tissue biopsy in certain clinical scenarios, which may support timely treatment decisions.
Liquid biopsy is most commonly used in cancers such as lung, colorectal, breast, and prostate cancer, particularly in advanced stages. Its performance varies by tumor type and burden, with higher detection rates in metastatic disease.
See also: AI 'Liquid Biopsies' Using Cell-Free DNA, Protein Biomarkers, Aid Early Detection Of Ovarian Cancer
Liquid biopsy offers several advantages that make it attractive in oncology:
Minimally invasive and safer than tissue biopsy
Enables repeated sampling for longitudinal monitoring
Captures tumor heterogeneity across multiple metastatic sites
Provides faster molecular insights in certain clinical settings
These features support its role in precision oncology and dynamic disease monitoring.²
Despite its promise, several liquid biopsy limitations affect clinical use.
Early-stage tumors release very small amounts of ctDNA, making detection difficult.⁸
Levels of ctDNA vary between patients and tumor types. Pre-analytical variables such as time to plasma separation, type of collection tubes, and DNA degradation during handling can significantly affect accuracy.⁹
Clonal hematopoiesis can introduce mutations unrelated to cancer, contributing to false positives in liquid biopsy.³
Clonal hematopoiesis is more common with age and can confound mutation interpretation.
Different platforms use varying methods, leading to inconsistencies across laboratories.⁹
Interpreting results requires bioinformatics support and clinical correlation.
High costs and limited access to advanced sequencing technologies remain barriers, particularly in low and middle income settings.¹⁰
Liquid biopsy accuracy depends on multiple factors, including tumor type, stage, and tumor fraction. It is generally more reliable in advanced cancers, while sensitivity is lower in early-stage disease.
Factors such as clonal hematopoiesis and low tumor fraction can affect test accuracy, contributing to false positives and variability in results.
Recent literature emphasizes that liquid biopsy is a rapidly evolving field with strong clinical potential. Its most validated applications include:
Advanced cancer monitoring
Detection of resistance mutations
Guidance of targeted therapies
However, its use in population-wide screening remains investigational. Studies highlight the need for large-scale validation, improved sensitivity, and standardized protocols before routine implementation.¹¹
Integration with other diagnostic modalities such as imaging and clinical biomarkers is also being explored to improve overall accuracy.¹¹
India has seen increasing adoption of liquid biopsy, particularly in urban oncology centers and private diagnostics, driven by the growing demand for precision oncology and non-invasive cancer testing.
Tata Memorial Centre
MedGenome
Strand Life Sciences
Dr Lal PathLabs
These organizations offer liquid biopsy tests in India, particularly for lung, colorectal, and breast cancers, with services ranging from hospital-based molecular oncology programs to large-scale genomic diagnostics.
4baseCare
HaystackAnalytics
PredOmix
OncoStem Diagnostics
These companies are expanding the availability of liquid biopsy in India, focusing on areas such as targeted therapy selection, early cancer detection research, and AI-driven biomarker analysis.
Market analyses indicate that the Indian liquid biopsy sector is expanding due to increasing cancer incidence, growing adoption of precision medicine, and rising demand for non-invasive diagnostics.¹²
The market was valued at approximately USD 363.96 million in 2024 and is projected to reach around USD 1.09 billion by 2035, with an estimated compound annual growth rate of about 10.5%.¹²
India currently accounts for a small but growing share of the global market, contributing roughly 3.2% in 2024, and is considered one of the fastest-growing regions in Asia-Pacific for liquid biopsy technologies.¹³
Within this space, the early cancer detection and monitoring segment is expanding rapidly. It was valued at approximately USD 71.3 million in 2024 and is expected to reach around USD 243.5 million by 2033, growing at an estimated 14.7% compound annual growth rate.¹³
From a technology perspective, circulating tumor cells currently account for a significant share of clinical applications, while exosomes and extracellular vesicles are emerging as one of the fastest-growing biomarker categories.¹³
Although oncology remains the primary application area, other uses such as prenatal testing are also expanding, indicating broader diagnostic potential beyond cancer.¹²
Despite this growth, several barriers remain:
High out-of-pocket expenditure
Limited insurance coverage for genomic testing
Uneven access across regions
Addressing these challenges will require policy support, cost reduction, and wider integration into public healthcare systems.
Liquid biopsy is best understood as a complementary diagnostic tool rather than a replacement for traditional biopsy.
Its future role is likely to include:
Monitoring disease progression and treatment response
Supporting personalized therapy decisions
Assisting in early detection, pending further validation
Advances in sequencing, bioinformatics, and biomarker discovery are expected to improve its clinical utility in the coming years.⁸
The rapid expansion of this market reflects a broader shift toward molecular diagnostics, where genomics, high-throughput sequencing, and data-driven approaches are increasingly integrated into routine cancer care.¹³
Liquid biopsy represents a shift in cancer detection through blood toward minimally invasive and molecularly informed approaches. Liquid biopsy enables clinicians to track cancer in real time and tailor treatment strategies more precisely.
At present, it does not replace conventional diagnostic methods. Its strongest role lies in monitoring, detecting relapse, and guiding targeted therapy. With continued research and technological refinement, it may expand into earlier stages of cancer detection.
For now, liquid biopsy reflects an important step in the transition from static diagnosis to dynamic disease monitoring. Its impact will depend on how well it is integrated with existing diagnostic pathways rather than replacing them.
See also: Man from Manipur Goes in for Biopsy, Alleges Doctor Removed His Genitals Without Consent
Can liquid biopsy detect cancer early?
Liquid biopsy has potential for early cancer detection, but current sensitivity is limited in early-stage disease due to low tumor DNA levels in blood.
How accurate is liquid biopsy?
Liquid biopsy accuracy varies by cancer type and stage. It tends to perform better in advanced cancers, while early detection remains challenging.
Is liquid biopsy available in India?
Yes, several centers and companies now offer liquid biopsy tests in India, particularly in major cities and specialized oncology centers.
Is liquid biopsy better than tissue biopsy?
Liquid biopsy complements tissue biopsy. Tissue biopsy provides structural detail, while liquid biopsy offers dynamic molecular information.
Kumar, S., et al. “Liquid Biopsy: A Timely Technology Waiting to Be Taken Seriously.” National Medical Journal of India. https://nmji.in/liquid-biopsy-a-timely-technology-waiting-to-be-taken-seriously/
Wan, J. C. M., et al. “Liquid Biopsies Come of Age.” Nature Reviews Cancer. https://pmc.ncbi.nlm.nih.gov/articles/PMC10285278/
“Emerging Role of Liquid Biopsy in Early Cancer Detection.” PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC12409318/
“Liquid Biopsy: A Potential and Promising Tool.” Indian Journal of Cancer. https://journals.lww.com/indianjcancer/fulltext/2017/54001/liquid_biopsy__a_potential_and_promising.4.aspx
“Applications of Liquid Biopsy in Oncology.” PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC11743551/
“Application of Liquid Biopsy in Lung Cancer.” Indian Journal of Pathology and Microbiology. https://journals.lww.com/ijpm/fulltext/2024/67030/application_of_liquid_biopsy_in_lung_cancer.2.aspx
“Liquid Biopsy in Precision Oncology: Current Insights.” Ovid. https://www.ovid.com/jnls/ijpmmm/fulltext/10.4103/ijpmmm.ijpmmm_19_25~liquid-biopsy-in-precision-oncology-current-insights-and
“Liquid Biopsy and Early Cancer Detection.” PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC12409318/
NSCRI. “Liquid Biopsy Explained.” https://nscri.in/blog-details/liquid-biopsy
“Clinical Applications and Challenges of Liquid Biopsy.” ScienceDirect. https://www.sciencedirect.com/science/article/pii/S2950195424000158
“Liquid Biopsy in Clinical Practice.” JPMER. https://www.jpmer.com/abstractArticleContentBrowse/JPMER/33168/JPJ/fullText
“India Liquid Biopsy Market.” Market Research Future. https://www.marketresearchfuture.com/reports/india-liquid-biopsy-market-44663
“Liquid Biopsy for Early Cancer Detection and Monitoring Market India.” Grand View Research. https://www.grandviewresearch.com/horizon/outlook/liquid-biopsy-for-early-cancer-detection-and-monitoring-market/india
