“Diagnosis in oncology should predict the disease before it manifests itself”
Molecular diagnostic methods are developing with revolutionary leaps and in the next ten years, familiar views on the principles and approaches in the diagnosis of tumor diseases can radically change. At the same time, there are more questions than answers in the laboratory diagnosis of cancer. Let us dwell on some of them.
Candidate of Medical Sciences expressed his point of view on the applied aspects of applying laboratory research in this area. Vasily Yurasov.
What place does laboratory medicine take in the diagnosis of cancer?
Laboratory medicine, or rather laboratory diagnostics, is not an independent field of medicine, but a tool that helps a practitioner with a comprehensive examination of the patient to make the correct diagnosis. According to the results of a laboratory test, one cannot say that the patient has oncological pathology. Laboratory diagnostics should be considered as an additional tool in the comprehensive diagnosis and monitoring of cancer.
What does laboratory diagnostics for oncology offer today?
The possibilities of laboratory diagnostics in oncology can be divided into several directions. Firstly, these are the possibilities of modern genetics. Genetic examination of a patient allows predicting the risks of developing cancer. In fact, in this context we are talking about predictive medicine, which allows revealing features in the structure of human genes, in another way – gene polymorphisms. By detecting changes in the structure of genes in a patient, one can assume a slowdown in the metabolism of these compounds. This increases the likelihood of toxic chemicals accumulating in the body. Such substances can damage DNA with the occurrence of somatic mutations (a prerequisite for the development of tumors).
If the likelihood of developing a tumor is predictable, what does it give the patient and the doctor?
Timely detection of gene polymorphisms is an opportunity for a geneticist to give the patient recommendations that can eliminate the influence of adverse environmental factors, which can subsequently lead to the development of a tumor. Such a study is especially relevant if oncopathology is encountered in the immediate family of the patient. Genetics is a tool to increase the alertness of doctors to such patients. The patient, of course, can undergo a genetic examination on his own, but more correctly when any study is prescribed according to the indications of a doctor. For methods in predictive medicine, there are indications, especially with a family history and burdened heredity.
When is the best time to undergo a genetic examination?
A genetic study can be assigned to a patient of any age, but the sooner the better. This approach will allow the geneticist to give the patient timely recommendations, including the elimination of contact with toxic substances that can cause mutations in the DNA structure.
What substances are you talking about?
The most common are resins. For example, benzopyrenes, which are practically insoluble in water. In an unoxidized form, they penetrate between nitrogenous bases located in the core part of the double helix of DNA and cause their chemical rearrangements. Which leads to disruptions in the functioning of the genome as a whole, as well as processes that regulate the development and reproduction of cells.
What is being investigated as genetic markers?
The features in the DNA structure of genes encoding key xenobiotic metabolism enzymes are investigated. To predict the highest likelihood of the development of oncopathology is the joint work of a laboratory and a geneticist. Only in this context can the patient receive the correct conclusion and the necessary references.
What other groups of laboratory tests can help in oncology diagnostics?
It is appropriate to say about preventive diagnostics, which could form the basis of screening programs. However, screening research methods in terms of possible laboratory diagnosis of tumors did not work out. Due to the fact that laboratory methods that were used and continue to be used for early assessment of existing tumors have low sensitivity and specificity.
Tell us more about these test groups.
These groups of tests include tumor markers. An important and desirable component of the early diagnosis of cancer remains the detection of substances that allow to determine or suggest the presence of a tumor. Due to the fact that currently known tumor markers have low sensitivity and specificity, they cannot serve as evidence of the presence of a tumor in the body. If screening is based solely on the assessment of tumor markers, this can lead to an increase in the proportion of false negative results, which will lead to the failure to identify modern tumors. It is also possible to obtain a false-positive result, which will lead to the appointment of diagnostically unreasonable procedures, for example, biopsies, and treatment of the patient for non-existent pathology.