New research indicates that liquid biopsies could determine whether or not surgery would be beneficial for a cancer patient, including people with mesothelioma.

Mesothelioma is often treated with a multi-modal approach—surgery, chemotherapy and radiation. While this is the current standard of care, physicians and researchers know that surgical operations are risky and may not improve the patient’s prognosis.

Determining the Right Course of Treatment for Mesothelioma

For other types of cancer and diseases, doctors can sometimes look at different biomarkers—a measurable substance found in the patient’s body—to determine whether or not a specific treatment will be useful for the patient. Mesothelioma does not have any known prognostic biomarkers that indicate how well a particular treatment will work for any given patient.

New research is looking to change that. A phase 3 study is assessing whether doctors can use circulating tumor DNA (ctDNA)—DNA from cancer cells that circulate in the patient’s blood—to decide if a patient should undergo surgery.

So far the research has shown that ctDNA can effectively determine if surgery would help a patient prolong their life expectancy.

But, before ctDNA can be regularly used as a prognostic biomarker for mesothelioma, the researchers need to show that their idea holds with a larger patient population.

About Liquid Biopsy Testing

Unlike a tissue biopsy which studies a piece of the tumor, or cytology which tests fluid in the lungs, a liquid biopsy is a blood test. In this blood test, doctors look for circulating tumor DNA (ctDNA).

All cells have a life span. They form, they grow, and they die. When they die, the cells are broken down, and their DNA is released into the bloodstream. This DNA is known as circulating cell-free DNA (ccfDNA).

When a person has cancer, some of this DNA comes from tumor cells—circulating tumor DNA or ctDNA. In the early stages of cancer, ctDNA will make up about 1% of the free-floating DNA. In late-stage cancer it can make up around 40% of the ccfDNA.

Measuring ctDNA in cancer care is not a new idea. It’s already used with other cancers for a variety of reasons:

  • Detects and diagnoses a tumor
  • Helps doctors know which treatments may be more effective
  • Shows a treatment is working when levels have reduced
  • Indicates remission if there is no ctDNA in the bloodstream

Determining Pleural Mesothelioma Surgery Candidates

Not everyone who has mesothelioma is eligible or a good candidate for surgery. One reason is that most patients with mesothelioma are over 70, which means that surgery has some added risks due to declining health with age. In addition to the increased risks, undergoing surgery might not improve the patient’s outcome.

The additional risks and potential to not improve patients’ situations is why doctors consider other factors before recommending surgery to an individual. Some of the factors are the disease stage, location and cell type. Other factors include the patient’s age, gender and overall health. But in light of this new study, doctors might also start considering the presence of ctDNA.

Patients With High ctDNA Have Worse Surgery Prognosis

If the liquid biopsy results show a patient has a high level of mesothelioma ctDNA, they may not be considered eligible for surgery. The current study has shown that patients with a lot of ctDNA have a worse outcome than patients with a lower level of ctDNA.

This knowledge could mean that ctDNA levels can be used as a prognostic biomarker, which is a needed marker. Doctors are in search of new biomarkers that indicate treatment effectiveness and are currently studying others, including certain genes. At this moment doctors mostly rely on diagnostic biomarkers—markers that can help diagnose the patient for mesothelioma.

Personalized Treatment for Mesothelioma

Finding new prognostic biomarkers, like ctDNA, is another step forward in the goal of providing a better-tailored treatment to mesothelioma patients based on their genetics and other biomarkers. Each patient responds differently to mesothelioma treatments. The use of biomarkers and genetic markers can help determine which treatment will be the best for each patient.

It’s essential to work with a specialist to get access to the latest treatment technology and get the most personalized treatment plan possible.

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Sources
  1. "Cancer Researchers Highlight Clinical Potential of Liquid Biopsy Using Droplet Digital PCR Technology," Select Science. Retrieved from: https://www.selectscience.net/industry-news/cancer-researchers-highlight-clinical-potential-of-liquid-biopsy-using-droplet-digital-pcr-technology/?&artID=48944. Accessed May 2, 2019.
  2. "ctDNA and CTCs in Liquid Biopsy – Current Status and Where We Need to Progress," Computational and Structural Biotechnology Journal. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6024152/. Accessed May 2, 2019.
  3. "What is circulating tumor DNA and how is it used to diagnose and manage cancer?" Genetics Home Reference. Retrieved from: https://ghr.nlm.nih.gov/primer/testing/circulatingtumordna. Accessed May 2, 2019.

Last modified: May 11, 2019