The early diagnosis of any disease is essential for the treatment to obtain better results, and in the case of cancer it can be decisive to save the patient’s life and to avoid leaving sequelae. For this reason, scientists are investigating to develop early detection tests that are also as least invasive as possible. Now a new blood test –Galleri test– has shown its effectiveness for detect more than 50 types of cancerand even to reveal in most cases what the original location of the tumor.
The blood test has been tested in the SYMPLIFY study carried out by the NHS (National Health Service of the United Kingdom), in which 6,238 adults who had attended their primary care doctor’s office with suspicious symptoms of cancer in England or Wales participated, and it has allowed the detection of two out of three cancers and the original site of the cancer in 85% of these cases.
Patients were referred for urgent diagnostic imaging, endoscopy, or other tests to investigate suspicious symptoms of possible gynecologic, lung, or gastrointestinal cancer, or with nonspecific symptoms. The most frequently reported symptoms were unexplained weight loss (24.1%), changes in intestinal transit (22%), postmenopausal bleeding (16%), rectal bleeding (15.7%), abdominal pain (14 0.5%), pain (10.6%), difficulty swallowing (8.8%) and anemia (7.1%).
A simple blood test to diagnose cancer
The Galleri test consists of extracting a blood sample from the patient from which the DNA is isolated and analyzed to look for what is known as cell-free DNA or cfDNA that provides information on pathological processes. Genomic sequencing is used to detect chemical changes in DNA – methylation – that control gene expression, and a classifier developed with machine learning (artificial intelligence) uses this data to detect abnormal methylation patterns that suggest the presence of cancer. The machine learning classifier can also predict which area of the body the cancer is in, and the results are known within 10 business days of the sample arriving at the lab.
Approximately 75% of those who tested positive in the blood test had cancer, while only 2.5% of those who tested negative had cancer.
During the study, 368 (6.7%) of the 5,461 evaluable patients were diagnosed with cancer using traditional tests such as scans and biopsies. The most common cancer diagnoses were colorectal (37.2%), lung (22.0%), uterus (8.2%), esophagogastric (6%), and ovarian (3.8%). Approximately 75% of those who tested positive in the blood test had cancer, while only 2.5% of those who tested negative had cancer.
Although this test is not precise enough to “confirm or rule out the presence of cancer”, it is very useful for patients, Mark Middleton, the trial’s lead investigator, told the BBC, adding: “The test had an accuracy of 85% in detecting the site where the cancer originated. And that can be really helpful because a lot of times when you’re in front of a patient it’s not obvious what tests are needed to determine if their symptoms are due to cancer.” “With that test prediction we can decide whether to do an endoscopic exam or a scan and make sure we do the right test the first time.”
“Early cancer detection and subsequent intervention have the potential to greatly improve patient outcomes. Most patients diagnosed with cancer first see a primary care physician to investigate for symptoms indicative of cancer, such as weight loss, anemia, or abdominal pain, which can be complex because there are multiple potential causes. . New tools are needed that can accelerate the cancer diagnosis and potentially avoid invasive and costly investigations to more accurately classify patients presenting non-specific cancer symptoms”, said Brian D. Nicholson, associate professor in the Nuffield Department of Primary Care Health Sciences at Oxford and co-principal investigator of the study.
The SYMPLIFY study has been sponsored by the University of Oxford, which has been in charge of the collection, analysis and interpretation of the data. The US healthcare company GRAIL has funded the work with support from England’s NHS, Wales’ NHS, the National Institute for Health and Care Research (NIHR) and the NIHR Oxford Biomedical Research Centre.
Source: www.webconsultas.com
