"FDA Approves Blood Tests That Can Help Guide Cancer Treatment" was originally published by the National Cancer Institute. | October 15, 2020, by NCI Staff
Doctors have traditionally based treatment decisions on features like the organ in which the cancer started growing, whether the cancer has spread, and whether the patient has other health conditions. Now they often use another feature to guide treatment: genetic changes in the tumor.
Certain therapies, called targeted therapies and immunotherapies, work best against tumors that have specific genetic changes. The newly approved tests identify genetic changes, including mutations, by scanning DNA that tumors have shed into the blood.
Doctors can then use that information to determine if there is a targeted therapy or immunotherapy that is likely to work for the patient. Analyzing genetic changes in a patient’s cancer is called tumor profiling, genomic profiling, or tumor sequencing.
Both Guardant360 CDx and FoundationOne Liquid CDx are approved for people with any solid cancer (e.g., lung, prostate), but not for those with blood cancers. While FDA has approved other blood tests that check for the presence a single gene mutation in tumor DNA, these are the first approved blood tests that check for multiple cancer-related genetic changes.
Liquid biopsies can sometimes be an alternative to a traditional biopsy, in which a sample of a tumor is removed with a needle or during surgery. They are considered less invasive and quicker than a traditional tissue biopsy.
“It’s great that we’ve crossed that hurdle now. It’s great for patients [because] it’s easier to get,” he said.
See complete article @ NIH (https://www.cancer.gov/news-events/cancer-currents-blog/2020/fda-guardant-360-foundation-one-cancer-liquid-biopsy)
GENETICS VS. GENOMICS
Genetics and genomics sound alike and are often used interchangeably, yet important scientific and clinical distinctions exist between these two scientific fields of study. The classical definition of genetics is the study of heredity, how characteristics and traits (phenotypes) of a living organism are transmitted from one generation to the next. This occurs via deoxyribonucleic acid (DNA), a double helix molecule in the cell’s nucleus that comprises genes—the basic unit of heredity. Many of the early principles and rules of heredity were discovered by an Augustinian monk and scientist, Gregor Mendel. His seminal research with pea plants in the mid-1800’s laid the foundation for modern-day genetics.
Genomics is the next evolution of classical genetics, and became possible only in recent decades due significant advances in DNA sequencing and computational biology. In 1976, Belgian scientists succeeded in fully sequencing the genome of bacteriophage MS2, a bacteria-infecting virus. They identified all 3,569 DNA base pairs, and the 4 nucleotides (Adenosine, Cytosine, Guanine and Tyrosine) that make up the DNA code. The first animal genome was completely sequenced in 1998. Five years later, with more than 1,000 researchers from six countries collaborating on the Human Genome Project, all 3.2 billion DNA base pairs in the human genome were identified. Genomics is the study of the entirety of an organism’s genes—the genome. Genomic researchers analyze enormous amounts of DNA-sequence data to find variations that affect health, disease or drug response. In humans, that means searching through about 3.2 billion units of DNA across 23,000 genes.
See complete article: INHERITING CANCER- 12/5/2020
The strategy of relying on a (PSA) blood test as the precursor to a biopsy required significant reassessment. Though approved by the FDA in 1986 as the gold standard for monitoring cancer relapses, increasing reports continue to indicate that elevated PSA levels in over 70% of men show a false positive reading- and does not conclude a malignant cancer. (NIH ref). Because of the inaccuracies of the PSA test and the risk of side effects, many centers are now using imaging solutions like ultrasound 3-D Doppler and MRI before considering a biopsy.
Patient-Specific Anxiety: "My PSA was 22. I had a biopsy; it was benign...GOOD! The biopsy showed inflammation, so I had a (surgical) biopsy I didn’t need... BAD! There has to be a better way!”
The DIGITAL MOVEMENT and the "end of FILM in radiology" was part of the global tech evolution- driven by the "Economics of Scale theory of Faster-Better-Cheaper". The digital imaging revolution harvested and processed images from an electronic photo conductor, managed bio-information into electronic pixels for more efficient management of diagnostic studies. The Digital state allowed for computerized intervention to optimize and expand the data acquiring process to new heights of study including 3D modeling- offering a 3D visualization of anatomical studies. This also paved the way for the induction of AI (artificial intelligence) which was developed to automate analytical paradigms (algorithms) for quicker analysis, advanced workflow, optimized visual dissection, extrapolation and 'prediction' of any biological information with remarkable performance. (see complete article)
1) Image #1: (Credit: Adapted from World J Gastroenterol. October 2016. doi:10.3748/wjg.v22.i38.8480. CC BY-NC 4.0)
3) Circulating tumor DNA as a liquid biopsy target for detection of pancreatic cancer https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5064029/