Liquid biopsy: Less invasive test to track, treat cancer

June 09, 2019
Liquid biopsy
Liquid biopsy

WHEN a patient has a suspicious lump or shows cancer symptoms, one of the first things a doctor can perform is a tissue biopsy. This procedure collects cells for a closer examination to determine if cancer is indeed present, indicate what type it is, and provide clues on the course the disease is likely to take (prognosis) – which in turn, impacts the treatment the patient will receive.

Though remaining the gold standard in detecting and getting information on cancer, tissue biopsies can be risky, invasive, and painful. The inaccessibility of a tumor, as well as existing health conditions, often prevent some patients from undergoing the procedure. Still, there is no question about the importance of biopsies as these help guide doctors on personalized treatment strategies for their patients.     

According to Makati Medical Center’s Dr. Jose Maria C. Avila, co-director of the Center for Regenerative Medicine (CRM), the hospital has, in recent years, began offering liquid biopsy as a complementary procedure for monitoring and treating cancer patients.

“Because of how a tissue biopsy is conducted, repeatedly performing the procedure will be difficult for patients. But we still need to track tumors as they change and develop overtime to allow doctors to gauge a patient’s response to treatment and make necessary adjustments when needed.”

Liquid biopsy essentially uses blood from a patient to collect a sample of cancer cells or parts of DNA. “The procedure is less invasive since we are only drawing blood,” Dr. Avila said. “That’s easier on a patient since we have to perform the procedure a number of times to monitor their progress.”

Another benefit is being able to further personalize treatment. The procedure detects mutations from fragments collected in the blood, and a mutation of a tumor can vary greatly in the kind of treatment it requires.

“This is personalized medicine. A tumor will have a mutation that is unique, and there’s a treatment needed for this particular mutation, and this individual cancer. A kind of treatment can work for one patient but not for another, and we want to be able to make the best decisions for each individual patient,” she added.

Currently, MakatiMed utilizes liquid biopsy as a complementary procedure, and not as a replacement to tissue biopsy – at least not yet, as the approach is still evolving. “What we utilize it for right now is on the prognostic side, for monitoring patients’ response to treatment. Although, there are certain circumstances wherein liquid biopsy may be considered an option,” Dr. Avila stressed.

These include if the patient cannot undergo tissue biopsy due to the location of the tumor or other factors affecting his or her health condition, or if the situation is critical and tissue biopsy will present complications in procuring samples as quickly as possible.    

The CRM has also developed a “homebrew” liquid biopsy for its patients. “Our method detects gene expressions. Gene expressions determine what the cell can do and how it responds to its changing environment. There are a number of gene expressions that correspond to a certain type of cancer,” said Dr. Avila.

As of now, the CRM is offering the liquid biopsy procedure for patients with lung cancer, prostate cancer, breast cancer, and soon, colon cancer. MakatiMed has also selected the U.S.-based specialty cancer diagnostics company Precipio, Inc. as its provider for the mutation enhancement technology used in liquid biopsies.

“With liquid biopsy as a viable, effective and less invasive monitoring procedure to help address the challenges of tissue biopsies, MakatiMed is able to consistently provide quality healthcare for our patients,” Dr. Avila concluded.