Liquid Biopsies In Cancer: Seek and Destroy

Joseph R. Anticaglia MD
Medical Advisory Board

The best chance for patience winning the battle against cancer, in addition to a healthy lifestyle, is early detection, and precise, treatment of this death-dealing disease. Liquid biopsy, (LB), is a term first used around 2010. It’s a blood test that detects and analyzes circulating tumor cells and their products released by cancer cells into the blood.

When cancer cells die, they are replaced with other cancer cells. The dead cancer cells scatter cancer-connected material into the bloodstream called circulating tumor DNA, ctDNA. The objective of scientists is to use blood samples to identify, treat and monitor cancer to better manage patients.

Presently, liquid biopsy doesn’t replace a tissue biopsy’s usefulness in diagnosing, and classifying tumors. But LB technology is making progress in detecting, characterizing, and managing cancer. There are notable advantages of LB.

Advantages of Liquid Biopsy

1. Non-Invasive
   LB draws a blood sample to evaluate cancer, and avoids invasive tissue biopsies which can be uncomfortable, and be the cause of complications
2. Early Detection
   Liquid biopsy can detect cancer at an early stage, even before symptoms appear, or findings on an MRI.
3. Monitoring
   Patients ask, “Is my cancer growing, shrinking, or is it gone?” Repeated LB tests can keep track of a person’s tumor, and answer questions such as whether the cancer treatment is working? Has the cancer type changed? Should doctors switch to a different treatment regime? Has it metastasized to different parts of the body?
4. Repeatability
   Liquid biopsy can be repeated multiple times using blood samples to monitor disease progression and response to treatment.
5. Cost
   LB may be less expensive than cancer tissue biopsies.

Disadvantages

1. Limited sensitivity: Liquid biopsy may not always detect the presence of cancer.
2. False positives: Liquid biopsy can sometimes produce false-positive results, which can lead to unnecessary further testing and anxiety for patients.
3. Cost: Liquid biopsy can be more expensive than traditional biopsy techniques.
4. Limited availability: Liquid biopsy may not be available in all medical centers, and may not be covered by all insurance plans, making it inaccessible for some patients.

Liquid biopsy is a non-invasive blood test that looks for abnormal genetic pieces of DNA from cancer cells, or their products in the bloodstream. Using this technology, clinicians aim to provide cancer patients with a personalized, targeted approach in the management of this deadly disease.

There are advantages to LB compared to tissue biopsy, but more research is needed to address the test’s limitations for it to become widely used in clinical practice; and as a screening test to identify cancer in individuals before symptoms, and signs appear.

References

1. Mina Nikanjam, et al Liquid biopsy: current technology and clinical applications; Journal of Hematology & Oncology, Sept. 12, 2022
2. Joseph R. Anticaglia, MD; Biomarkers Are Essential Medical Tools; Doctor’s Column HC Smart 2023
3. Joseph R. Anticaglia, Precision Medicine (Personalized Medicine) Is It Right For You? Doctor’s Column HC Smart, 2023
4. Johns Hopkins; Single Blood Test Screens for Eight Cancer Types; 01/18/2018
5. Sandy McDowell; Liquid Biopsies: Past, Present, and Future; American Cancer Society, February 12, 2018

Glossary

A biomarker is a biological molecule used to diagnose a normal, or abnormal disease, condition, or process. It’s found in blood and tissues. urine, or other bodily fluids. There are different types of biomarkers.

ctDNA — circulating tumor DNA

cfDNA — Cell-free DNA

CTC — Circulating tumor cells

This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.