Liquid biopsy has completely transformed clinical oncology, creating a new dimension for cancer care with personalized treatment. This minimally invasive technique is highly beneficial in providing better clinical outcomes by identifying actionable cancer biomarkers, early diagnosis, and easing tumor sampling, especially when solid tissue biopsies are insufficient or unable to obtain.

What is Liquid Biopsy?

Liquid biopsies are minimally invasive blood-based tests that involve isolating tumor-derived entities present in body fluids, such as circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and plasma cell-free DNA (cfDNA), followed by analyzing the genomic data contained within them.

In recent years, liquid biopsy has emerged as a powerful tool in the fight against cancer. Here are some of the ways it is revolutionizing cancer treatment:

1. Early detection of the disease

A stark observation seen in cancer patients is the presence of a high level of cfDNA in their blood as a result of cellular necrosis or apoptosis as tumor cells divide faster than normal cells, and cfDNAs are released in a high proportion. The fraction of cfDNA that is derived from tumor cells is named circulating tumor DNA (ctDNA). In recent years, both cfDNA and ctDNA have gotten huge attention as novel blood biomarkers, as quantification and kinetic analysis of cfDNA and molecular profiling of ctDNA have suggested their predictive and prognostic values.

One of the most promising and crucial features of liquid biopsy is that it enables the early detection and screening of cancer. We are aware of the fact that early diagnosis of cancer paves the way to eradicate cancer cells, therefore we can rely on this potential technique which can allow patients to improve their quality of life (QoL).

2. Monitoring Treatment Response

There are many challenges faced by the patient in a tissue biopsy since it is an invasive technique such as continuous monitoring of the prognosis, tumor heterogeneity, uncertainty of tissue availability, etc which can be overcome by Liquid Biopsy.

Liquid biopsy being a simple blood test, therefore, has become a better alternative for continuously monitoring the prognosis and progression of the tumor. This simple blood-based test enables the clinician to make treatment decisions that will give the patient better chances of fighting cancer.

3. Personalized Treatment

The goal of personalized treatment is to eliminate the “one size fits all” model of treatment regimens, which is centered on average response to care, by shifting the emphasis to tailored treatment according to disease biology and predicted treatment response in each patient.

Unlike other diagnostic techniques, the tumor-derived blood analytes in liquid biopsy like cfDNA, ctDNA, CTCs, etc, reflect a complete picture of the tumor’s mutation profile, enabling targeted therapy directed toward a single mutant gene contributing to personalizing cancer treatment regimens for every patient.

4. Minimal Residual Disease

Liquid biopsy can also be used to detect Minimal Residual Disease (MRD) in cancer patients who have undergone treatment. MRD refers to the small number of cancer cells that survive after treatment. These cells can be difficult to detect with traditional imaging scans, resulting in disease recurrence.

Doctors can detect MRD in patients who have received treatment by analyzing the levels of cfDNA, ctDNA, or CTCs in their blood. This data can be used to track patients’ disease recurrence and adjust treatment plans as needed.

In conclusion, liquid biopsy is a promising technology that is reinventing how cancer is diagnosed, monitored, and treated. It provides a less invasive, less expensive approach to cancer screening and can provide real-time information about how a tumor is responding to treatment, as well as indicating the likelihood of relapse in patients, allowing them to plan their treatment accordingly.

References

1. Lone, S. N., Nisar, S., Masoodi, T., Singh, M., Rizwan, A., Hashem, S., … & Macha, M. A. (2022). Liquid biopsy: A step closer to transform diagnosis, prognosis, and future of cancer treatments. Molecular cancer, 21(1), 1-22.
2. Yan Yan-yan, Guo Qiao-ru, Wang Feng-hua, et al. (2021). Cell-free DNA: Hope and potential application in cancer. Frontiers, 9.
3. Zhou, H., Zhu, L., Song, J., Wang, G., Li, P., Li, W., … & Zhang, Y. (2022). Liquid biopsy at the frontier of detection, prognosis, and progression monitoring in colorectal cancer. Molecular Cancer, 21(1), 86.
4. Crosby, D. (2022). Delivering on the promise of early detection with liquid biopsies. British Journal of Cancer, 126(3), 313-315.