Non-invasive screening
Researchers from the Dana-Farber Cancer Institute, USA, have reported a non-invasive test that can detect earlier forms of kidney cancer, helping to reduce mortality from this disease.
According to experts, 73750 new cases of kidney cancer will be diagnosed in 2020, and about 14,830 people will die from this pathology. About 35% of oncological diseases are diagnosed only after they have spread beyond the kidneys. Small early forms of kidney tumors usually do not cause clinical symptoms, they are often accidentally detected when scanning the abdominal organs performed for another purpose. To date, there are no screening tests recommended for early detection of kidney cancer in the population. First of all, the new test described in the study could be used to screen people with burdened heredity or those who previously had kidney cancer.
Noninvasive liquid biopsies are designed to search for circulating tumor DNA in the blood and other biological fluids that the tumor secretes. This diagnostic method is being actively introduced into clinical practice as a means of early detection of certain types of tumors. Nevertheless, kidney cancer is one of the most difficult to detect tumors, because it releases into the blood an insufficient amount of abnormal DNA to determine. The new test can detect tumor DNA in the blood, even if its level is very low. This means that the disease can be detected at an early stage.
The technical name of the new test is cell–free methylated DNA immunoprecipitation and high-throughput sequencing (cell-free methylated DNA immunoprecipitation and high-throughput sequencing, cfMeDIP-seq). Unlike other liquid biopsy methods that look for mutations in tumor DNA that characterize the type and location of cancer, cfMeDIP-seq detects abnormal methylation – the addition of chemical tags to DNA that does not change the genetic code, but can affect their function.
The method was tested on samples from 99 patients with early and advanced kidney cancer, 15 patients with stage 4 bladder cancer and 28 healthy people without cancer. Analyzing blood serum using the cfMeDIP-seq test, the researchers reported almost perfect identification of patients at all stages of kidney cancer.
The method was less accurate with similar testing of urine samples, but the researchers believe that performance can be improved.
If the test proves effective in larger studies and becomes widely applicable in clinical practice, screening using a urine sample will be even less invasive than a blood test, not to mention a biopsy.
Article by P.V.Nuzzo et al. Detection of renal cell carcinoma using plasma and urine cell-free DNA methylomes is published in the journal Nature Medicine.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of the Dana-Farber Cancer Institute: Biomarker Test Highly Accurate in Detecting Early Kidney Cancer.