What does a blood test involve?

A blood test involves drawing a small amount of blood from a vein (usually a vein in the arm) and sending it to a laboratory for analysis. The purpose is to examine cancer-related indicators or assess organ function, which may be affected by the cancer or its treatment. The specific type of blood test depends on the patient’s symptoms, medical history, and the type of cancer suspected.

Application of blood tests in cancer care

1. Detect tumor markers

Some blood tests detect substances called tumor markers that are produced by cancer cells or the body’s response to cancer. Elevated levels of certain tumor markers may indicate the presence of specific cancers. For example:

– Prostate-specific antigen (PSA): prostate cancer.

– CA-125: Ovarian cancer.

– CEA (carcinoembryonic antigen): colorectal cancer and other types.

2. Assess organ function

Blood tests such as complete blood counts (CBC), liver function tests (LFTs), and kidney function tests provide information about a patient’s overall health. These tests help evaluate the function of major organs such as the liver, kidneys, and bone marrow and are critical to diagnosis and treatment planning.

3. Detect abnormal cells

A complete blood count (CBC) is often used to detect blood cancers, such as leukemia and lymphoma, by measuring the levels of red blood cells, white blood cells, and platelets. Abnormal levels or the presence of immature cells may indicate a blood disorder or cancer.

4. Monitor treatment progress and recurrence

Blood tests are also used to monitor the effectiveness of cancer treatments and detect signs of recurrence. For example, a decrease in tumor marker levels may indicate a positive response to treatment, while an increase in levels may indicate cancer recurrence.

Advantages of blood tests in cancer care

1. Non-invasive and fast: Blood tests are relatively simple, minimally invasive, and can be done quickly, providing quick results to guide further diagnostic steps or treatment plans.

2. Monitoring and tracking: Blood tests are suitable for regular monitoring and can effectively track the progression of cancer, treatment effects and early detection of recurrence.

3. Support diagnosis and prognosis: Blood tests provide supporting evidence that can complement imaging studies and biopsies to provide a clearer view of a patient’s overall health and cancer status.

Limitations of blood tests in cancer

1. Insufficient specificity: Elevated levels of tumor markers or abnormal blood test results may be caused by non-cancerous conditions, resulting in false positives. Further diagnostic testing, such as imaging or biopsy, is usually required for confirmation.

2. Limitations to early detection: Blood tests are not always reliable at detecting early-stage cancer because tumor markers may not rise until the cancer progresses.

3. Variability in results: Normal ranges for blood test results can vary from laboratory to laboratory, as can the patient’s age or concomitant health conditions.

Conclusion

Blood tests are an important part of cancer care, providing critical information that aids in cancer detection, diagnosis, and monitoring. Although blood tests alone cannot diagnose cancer, they can reveal clues about abnormal cells, organ function and tumor markers that can help guide the process of diagnosis and treatment. Understanding the role of blood tests in cancer care can give patients a clearer understanding of the diagnostic process and understand how these tests contribute to the overall treatment plan.

Medical Disclaimer：

The information provided in this article is for educational and reference purposes only and does not constitute medical advice , and should not be used as a substitute for professional medical diagnosis, treatment or advice. Always consult your physician or other qualified health professional with any questions you may have regarding your medical condition or medical problems. The content of this article is not intended to recommend any specific test, treatment, or medication and should not be considered such advice. If you develop symptoms or need medical assistance, please contact a medical professional promptly.