Saliva Liquid Biopsy Study:
What did we learn?
More successful patient outcomes result from the combination of early detection and a personalized treatment strategy using cancer-specific genetic disease data. According to a World Health Organization (WHO) February 2022 publication, cancer is the leading cause of death worldwide (1 in 6). In addition, the numbers show lung cancer accounts for 1.8 million deaths and is reported to be the most common cause of cancer death. Approximately 230,000 U.S. citizens a year will receive a lung cancer diagnosis, with an estimated 135,000 deaths. Lung cancer deaths have become more numerous than the deaths from prostate, breast, brain, and colorectal cancer combined. It has now become the most common cause of cancer deaths in men and the second most common in women.
Most lung cancers (85%) fall into the category called non-small cell lung cancer (NSCLC). Though this form of lung cancer progresses more slowly than small cell lung cancer (SCLC), 40% of those living with NSCLC will have it spread beyond the lungs by the time it has been diagnosed. Doctors classify lung cancer types according to the size and shape of the cancer cells seen under a microscope. Around 13% of lung cancers are small-cell lung cancers (SCLC), and 84% are NSCLC. NSCLC is an umbrella term that includes several subsets, like adenocarcinoma, squamous cell, and large cell carcinoma. Many people receive a diagnosis of NSCLC after it has spread to other parts of their body. Changes in the DNA of the tumor cells can make cancer spread faster.
A tissue biopsy is currently considered the gold standard in a cancer diagnosis. This type of traditional solid tumor biopsy has several drawbacks both for the patient and the provider trying to identify the most successful treatment strategy. Some tumors are not easily accessible. Tumor biopsies can pose additional risks to the patient from the invasive nature as well as based on where the tumor is located. In addition, studies have shown that biopsies are not always representative of the entire tumor. Because many tumors are heterogeneous, different sites within the tumor can have different levels of gene expression and metastatic potential, and a tissue biopsy may not be indicative of all tumor phenotypes. During the course of a disease, cancers generally become more heterogeneous and divergent. As a result, the bulk of the tumor can harbor a diverse collection of cells with distinct and differing molecular signatures and different levels of sensitivity to treatment.
Liquid biopsy that delivers detection sensitivity closest to tissue biopsy-based genotyping of tumor-specific ctDNA has remained a challenge and an unmet clinical need. Although liquid biopsy and ctDNA analysis have quickly become a valuable, even lifesaving, and favored approach. The noninvasive use of saliva over blood still faces a big challenge. The sensitivity of liquid biopsy technologies for detecting ctDNA genomic alternations is limited by low concentration levels as well as by the molecule size and exposes the critical need for superior innovation capable of helping magnify detection sensitivity and increasing test reproducibility. In saliva, the EGFR ctDNA is almost exclusively ultrashort (usctDNA). Standard DNA preservation and extraction methods offer inadequate amounts of these tiny usctDNA fragments.
The published UCLA and Spectrum Solutions research collaboration collaboration focused on a new, sensitive, and non-invasive saliva-based liquid biopsy approach and has confirmed the existence as well as the ability to detect usctDNA in Saliva. After integrating the Spectrum Solutions SDNA-1000 saliva collection device with patented stabilizing and preservation chemistry, the research team at UCLA revealed the device-specific, sample prep point-of-collection advantages, including the ability to identify low ctDNA content with a high background of cfDNA noise, a 14-fold boost in sensitivity, and more to successfully demonstrate the proof of concept and feasibility of saliva for the non-invasive detection of cancer. [Read More…]