Will liquid biopsy be a step closer to cancer-free world?

Oncologists have always wanted to avoid the subjective nature of tissue biopsies, which always had an element of hit or miss attached to it. Liquid biopsy makes this possible for oncologists.

It is a non-invasive method in place of surgical biopsies, which allows the doctor to study a wide range of information about the developing tumor in the body with just a sample of your blood. For diagnosing tumors, tissue biopsies can be tricky, painful and quite costly. Moreover, there is always a risk of affecting the patient’s health. These are enough reasons for carrying forward the development in liquid biopsy as oncologists have always faced the challenged to come up with non-invasive methods of detecting tumors.

In our bodies, fragments of DNA from tumor cells are shed and passed on in our bloodstreams. These fragments can be used to non-invasively test early stage cancers. This method can help them monitor cell’s response to a therapeutic treatment and will help them learn why certain type of cancer cells resist these treatments. These traces of cancerous DNA give information about which cancer treatment will work best for the patient.

There are circulating tumor cells (CTCs) and Cell-free circulating tumor (ctDNA) found in the blood, which can be used to determine the progression of the disease. They are the plasma source of the tumor. Liquid biopsy requires only few millimeters of patient’s blood, making it tolerable and painless. The blood sample is reduced to even lesser quantity to extract the plasma, which is then analyzed for cancer DNA. Liquid biopsies performed through Cell free circulating tumor DNA (ctDNA) lets the scientists understand changes happening in the tumor on a molecular level in real time, which is a big deal considering how CTCs are doing clinically.

Most of the times, cancers have genetic mutations in them which are not regular in every part of the cancer, however if progressed, can turn even more fatal. Because of these irregularities, the tissue samples taken out for biopsy may not have similar pattern of mutations, which can make the doctors overlook an important detail. This is where liquid biopsy presents an improved way of catching these genetic mutations within the cancer DNA.

Most cancers have multiple genetic mutations and they may not have the same ones in all parts of the cancer. The tissue samples removed for biopsy may not show all mutations whereas liquid biopsies offer an improved chance of detecting these genetic changes. This will increase the chances of catching the disease in its early stages, before it completely develops.

However, throughout all this, the question remains; will liquid biopsy replace tissue biopsy?

The answer is no, not at least in the near future. It will however complement the screening process and make it incredibly easier to detect cancer at times when there is just not tissue available to perform tests on. This will let more patients get tested and take the treatment which is present in the market for them.