Liquid Biopsy Is the New Frontier in Cancer Diagnosis

When my husband was diagnosed with very early stage prostate cancer, it was determined that the best course of action was “watchful waiting” – that is, monitoring the cancer at six month intervals using biopsies of the prostate. It sounded reasonable.

What was not mentioned was the excruciating ordeal of prostate biopsy. Each time he went in for one, it took all day because of the side effects of blood clotting and blocking of the urethra. This led to catheterization as well as pain. After his third one he said, “Let’s just cut the damn prostate out. It’s gotta be better than these biopsies.”

Wouldn’t it be great to have the same information gleaned from a drop of blood?

Thanks to Dr. Dennis Lo, a researcher in Hong Kong, this technology may soon be available. He developed a technique called the “liquid biopsy,” which has shown great success in detecting liver and other cancers before they are symptomatic. He does this with a gene sequencing machine that analyzes the DNA in a person’s blood. Since dying cancer cells shed their DNA into the blood stream, a liquid biopsy can detect the presence of a cancer on a cellular level. This technology is already being used in China as part of prenatal monitoring, as the fetus sheds cells into the mother’s bloodstream during pregnancy.

Early detection of cancer has been behind the great improvement in cancer treatment over the last few decades. For example, one of the main reasons for the decline in colorectal cancer is the more frequent use of colonoscopies. For greater efficacy in early detection, liquid biopsy is being looked at with great interest by American researchers and companies as well. Eric Topol, a professor of genomics at the Scripps Research Institute, stated that this technology, will become the “stethoscope for the next 200 years.” A San Diego company, Illumina, which builds fast gene-sequencing machines, is excited about the market potential of as much as $40 billion. It manufactures these devices, some of which are as small as a cell phone, and the devices could be used in clinical trials very shortly.

The liquid biopsy is not a one-size-fits-all cancer detection system. As each cancer has unique DNA markers, part of the research is to identify those markers and apply them specifically.

As far as my husband is concerned, the day cannot come too soon when a liquid biopsy is available for his type of prostate cancer. Luckily his cancer seems to be in remission, and his biopsy schedule has been reduced. Perhaps by the next rodeo, he’ll be able to have a blood draw and call it a day.