Introduction to blood-based biomarkers

Breast cancer is the most common cancer in women in the United States, except for skin cancers. It accounts for about 30% (or 1 in 3) of all new female cancers each year. Overall, the average risk of a woman in the United States developing breast cancer sometime in her life is about 13% 1. This means there is a 1 in 8 chance she will develop breast cancer. Every year, more than 275,000 people are diagnosed with breast cancer in the country2.

Blood-based biomarkers are quantifiable indicators in the blood that can reveal information about various physiological or pathological processes in the body. These biomarkers are valuable medical tools for detecting disorders, tracking therapy responses, and forecasting results.

Biomarker blood tests also help in diagnosing, prognosis, and treating many malignancies. These biomarkers, frequently detected in the blood, give helpful information regarding cancer’s existence, progression, and features. For example, Prostate-specific antigen (PSA) for prostate cancer, CA-125 for ovarian cancer, and CEA for colorectal cancer.

Importance of early detection in managing cancer

Early-stage malignancies usually give room for more therapy choices, including less intrusive and more effective therapies. When the disease is diagnosed early on, treatment options such as surgery, radiation therapy, chemotherapy, or targeted medicines may be more effective for patients3.

For example, early-stage breast cancer can be treated with less invasive operations like lumpectomy (removal of the tumor and surrounding tissue) rather than mastectomy (total removal of the breast). Also, early-stage breast cancer treatment is usually less expensive for patients than advanced-stage disease management.

Early detection also identifies those at increased risk owing to genetic variables (such as BRCA gene mutations). This knowledge can lead to individualized screening and preventative interventions, such as greater surveillance or risk-reducing operations. Furthermore, detecting breast cancer early minimizes the chance of metastasis, which occurs when these cells travel to other regions of the body. Metastatic illness prevention is vital for better long-term results and prognosis.

Finally, early detection enables complete emotional assistance for patients and their families. Understanding that cancer is identified early and has a better chance of being effectively treated might help ease some of the emotional discomfort that comes with being diagnosed.

Understanding blood-based biomarkers

Blood-based biomarkers are chemicals or indicators found in the blood that may be analyzed and utilized to determine different physiological or pathological processes in the body.

They are essential for medical research, diagnosis, and disease treatment since they provide non-invasive and user-friendly approaches for measuring health and illness. Blood-based biomarkers might be proteins or nucleic acids (like DNA or RNA)4.

They can also be cells or other substances that reflect certain situations or changes in the body.

For example, raised levels of prostate-specific antigen (PSA) can indicate prostate cancer, whereas high levels of cardiac troponins can indicate heart muscle injury. Circulating cells, which include circulating tumor cells (CTCs), can also serve as cancer biomarkers. The presence of these cells in the circulation may suggest that cancer has migrated from its original location to other areas of the body.

Blood-based biomarkers in cancer detection and monitoring

Blood-based biomarkers provide a potent and diverse method for cancer detection. Their non-invasiveness, real-time monitoring capabilities, and the capacity to offer comprehensive molecular information.

Firstly, Biomarkers can also reveal information about the hormonal receptor status of breast cancer, namely the estrogen receptor (ER) and progesterone receptor (PR)5. This information helps to inform judgments about hormonal therapy, which can help treat hormone receptor-positive breast cancer.

Blood-based biomarkers provide a non-invasive alternative to established cancer diagnostic procedures like tissue biopsy. Collecting a blood sample is less intrusive than surgical treatments, which might lead to difficulties and hazards and is especially helpful for individuals needing more time to undertake invasive diagnostic tests.

For example, circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) can be early indicators of breast cancer. Detecting these indicators in the blood may predate the manifestation of symptoms and allow for early intervention.

Secondly, blood-based biomarkers, such as serum HER2 levels, can indicate HER2-positive breast cancer. This knowledge helps make treatment decisions, such as using targeted medicines like trastuzumab.

On top of this, changes in the levels of specific biomarkers testing before and after therapy might offer helpful information about the efficacy of the selected treatment, allowing healthcare practitioners to make appropriate modifications if necessary.

Common blood-based biomarkers in breast cancer

Several blood-based indicators are widely employed in the diagnosis and treatment of breast cancer. These indicators give necessary information regarding the tumor’s features, reaction to treatment, and overall prognosis.

Protein biomarkers

Protein biomarkers are proteins or peptides that may be evaluated in biological samples and utilized as indications of normal or aberrant biological processes such as certain disease states or reactions to treatments. These biomarkers are essential in many parts of medicine which include diagnosis, prognosis, disease progression tracking, and therapy response assessment6.

Examples of protein biomarkers

Some examples of biomarker proteins include estrogen receptor cells, progesterone receptor cells, and HER2 proteins.

Firstly, ER-positive breast cancer cells express estrogen receptors. Testing for the presence of ER determines if the malignancy is hormone receptor-positive, which might impact treatment options, including hormonal therapy7.

Similar to ER, the presence of progesterone receptors on breast cancer cells indicates hormone receptor-positive breast cancer. PR status is frequently measured with ER to help guide hormonal treatment recommendations.

HER2 is a protein that can be overexpressed in some breast tumors. About 15% to 20% of breast tumors have higher levels of a protein known as HER2. HER2-positive breast cancer is more aggressive, although targeted medicines like trastuzumab (Herceptin) can help treat it.

Genetic tumor markers

Genetic tumor indicators for breast cancer include particular genetic abnormalities or mutations that are connected with a raised chance of developing breast cancer. They can also impact the behavior of the tumor itself.

Examples of genetic tumor markers

For example, genetic changes in the BRCA1 and BRCA2 genes are well-known hereditary risk factors for breast cancer. Individuals with mutations in tumor genes are at a much higher risk of getting breast and ovarian cancer8.

Testing for BRCA mutations is important for identifying high-risk people, which allows for proactive screening and prevention strategies.

Circulating tumor cells (CTCs)

Circulating tumor cells (CTCs) are cancer cells that have separated from their source tumor and infiltrated the circulation. They circulate in the bloodstream and may lead to the development of metastases in distant organs.

CTCs in the circulation indicate that breast cancer has the potential to spread metastatically. According to studies, having more CTCs is related to a worse prognosis and an increased likelihood of illness recurrence9. Additionally, changes – or lack of change – in CTC counts may reflect therapy efficacy or resistance, altering treatment options.

Cell-Free DNA (cfDNA)

CfDNA is fragmented DNA that circulates freely in the circulation, originating from normal and malignant cells. The examination of cfDNA may assist in the early diagnosis of breast cancer. Tumor-derived cfDNA, also known as circulating tumor DNA (ctDNA), can be identified in the circulation, indicating the presence of malignancy before clinical signs appear10.

Monitoring variations in ctDNA levels over time can provide insights into the course of breast cancer. CfDNA analysis enables real-time monitoring of tumor dynamics, potentially detecting genetic alterations linked with disease progression.

Other applications of blood-based tumor markers

Blood-based biomarkers offer a wide variety of uses beyond biomarker testing for cancer treatment or detection. These biomarkers, which may be found in blood samples, give important information about many physiological and pathological processes in the body11.

For example, Troponins, creatine kinase-MB (CK-MB), and brain natriuretic peptide (BNP) are used to diagnose and monitor heart disease, including myocardial infarction (MI) and cardiac failure. Tau and beta-amyloid are also indicators of Alzheimer’s disease, and they can be tested in the blood to diagnose and track illness development.

CRP is an inflammatory marker that rises during inflammation. It is used to determine the presence and severity of inflammatory diseases. Also, glycated hemoglobin levels are a long-term indicator of blood glucose management in diabetics. Lastly, cholesterol (LDL, HDL) and triglyceride levels in the blood are vital indicators of cardiovascular risk.

The potential of blood-based biomarker research

Blood-based biomarker research has enormous promise in different domains of medicine and healthcare. Advancements in technology, molecular biology, and data analytics have extended the breadth and capabilities of blood-based biomarkers12. They have also provided prospects for early illness identification, individualized treatment methods, and improved patient outcomes.

Discovery of treatment targets

Blood-based biomarker research has led to the discovery of new treatment targets. Understanding illnesses’ molecular and genetic fingerprints can help create tailored medicines.

They have also shown the potential to detect and monitor neurodegenerative illnesses, including Alzheimer’s and Parkinson’s disease, and specific proteins and genetic markers discovered in the blood may explain various diseases’ underlying pathology and course13. By identifying causal agents, treatment choices can be more informed.

Disease monitoring capabilities

Blood-based biomarkers also enable remote monitoring of a patient’s health status. This is especially important in chronic conditions since it allows constant tracking without requiring numerous clinic visits14.

Final words

Blood-based biomarkers play a key role in early illness identification, evaluating therapy responses, predicting prognosis, and customizing medical interventions. Technological advances, such as liquid biopsy procedures, have increased the potential uses of blood-based biomarkers in various medical sectors.

Over the next decade, improvement in the sensitivity and specificity of biomarker testing such as using breast cancer biomarkers for the detection of breast cancer would improve patients’ diagnosis and quality of lives. It would also reduce the financial burden of healthcare on individuals who seek more precise methods of medical investigations.

DiviTum’s role in breast cancer monitoring

DiviTum is committed to improving patient outcomes for breast cancer patients – particularly those in the more advanced stages of the disease.

The DiviTum® TKa test is a tool that can help in the development of more tailored treatment plans for postmenopausal women with HR+ metastatic breast cancer. The test identifies whether patients are responding adequately to CDK4/6 inhibitor medication adequately, ultimately aiming to provide accurate and accessible disease monitoring to guide treatment strategies.

Healthcare providers, such as oncologists, can use the DiviTum® TKa test to track patient response early on and anytime during treatment. The test can also be used in tandem with traditional imaging to assess non-measurable disease. To learn more about test procurement, contact us.


  1. “Breast Cancer – Symptoms and Causes.” Mayo Clinic.
  2. “Breast Cancer.” The University of Texas: MD Anderson Cancer Center.
  3. “Why is early cancer diagnosis important?” Cancer Research UK.
  4. Hardy-Sosa, Anette. et al. “Diagnostic Accuracy of Blood-Based Biomarker Panels: A Systematic Review.” Frontiers in Aging Neuroscience, Volume 14. Published March 11, 2022.
  5. “Breast Cancer Biomarkers and Biomarker Tests.” Breast Cancer Organization.
  6. Boschetti, Egisto. et al. “Protein biomarkers for early detection of diseases: The decisive contribution of combinatorial peptide ligand libraries.” Journal of Proteomics, Volume 188, pp. 1–14. Published September 30, 2018.
  7. Klocker, E.V. and Suppan, C. “Biomarkers in HER2- positive disease.” Breast Care, 15(6), pp. 586–593. Published October 28, 2020.
  8. “BRCA Gene Mutations: Cancer risk and Genetic Testing.” National Cancer Institute.
  9. Lin, D. et al. “Circulating tumor cells: biology and clinical significance.” Signal Transduction and Targeted Therapy, 6(1). Published November 22, 2021.
  10. Yan, Y. et al. “Cell-Free DNA: hope and potential application in cancer.” Frontiers in Cell and Developmental Biology, 9.
  11. Holdenrieder, S. et al. “Clinically meaningful use of blood tumor markers in oncology.” BioMed Research International, 9, pp. 1–10. Published February 22, 2021.
  12. Pan, F.-F. et al. “The potential impact of clinical factors on blood-based biomarkers for Alzheimer’s disease.” Translational Neurodegeneration, 12(1). Published August 18, 2023.
  13. Gao, F. et al. “Blood-based biomarkers for Alzheimer’s disease: a multicenter-based cross-sectional and longitudinal study in China.” Science Bulletin, 68(16), pp. 1800–1808. Published August 30, 2023.
  14. Angioni, D. et al. “Blood Biomarkers from Research Use to Clinical Practice: What Must Be Done? A Report from the EU/US CTAD Task Force.” The Journal of Prevention of Alzheimer ’s Disease, 9, pp. 569-579. Published October 12, 2022.


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