Personalized and precision medicine (PPM) is becoming a high-priority aspect of medical science and practical healthcare. The idea is to determine what medications will effectively treat patients with due consideration for their genetic specifics and individual health disorders, as well as those of their relatives.
In due time, personalized treatment involving biomarkers will serve as the most important element of cancer prevention and routine cancer treatment and will help reduce cancer risks for potential patients.
A biomarker is a specification that can be objectively assessed for pinpointing a pathological or physiological process inside a human body. Doctors use biomarkers to evaluate the stage of any health disorder, to predict the treatment process and to choose individual treatment options, depending on a tumor’s molecular type.
For example, patients with breast or lung cancer suffer from tumors with typical gene mutations. In this connection, doctors all over the world prescribe targeted genome scanning and determine an individual list of biomarkers for targeted therapy.
There are three main types of biomarkers, Sergei Suchkov, Head of the Faculty of Translational Medicine at National Research Nuclear University MEPhI, told Rossiya Segodnya International Information Agency.
“Predictive biomarkers forecast health disorder risks and the likely response to planned and current treatment. Prognostic biomarkers provide data on how a health disorder may develop, regardless of specific treatment types; in other words, they predict a health disorder. Diagnostic biomarkers provide correct diagnoses at the right time,” he explained.
Numerous research projects have selected a number of biomarkers associated with tumors. The combined determination (multi-factorial screening and monitoring) guarantees more accurate diagnoses and makes it possible to determine a pre-cancer state, as well as reliable forecasts while streamlining the procedure for exposing metastases.
Studies of auxiliary biomarkers are becoming a mandatory element of treatment-diagnostic protocols for cancer patients, as well as preventive treatment protocols for risk group patients. This method provides oncologists with a unique clinical orientation tool and helps patients achieve their maximum life expectancy without relapses.
Biomarkers can diagnose malignant tumors much more effectively, helping doctors come up with the most effective treatment options. Biomarkers have spurred the development of the targeted therapy concept. Researchers have realized the need to develop special “targeted” medications capable of invading key pathogenic structures and correcting them.
In 2011, the US Food and Drug Administration (FDA) approved a number of instructions for targeted cancer therapy. The FDA approved the use of the Crizotinib and Vemurafenib medications. Objective bio-marking principles, rather than a doctor’s subjective opinion, were used to choose a course of treatment for the first time.
Today, doctors have to conduct a test based on the unique fluorescent in situ hybridization (FISH) method before appointing Crizotinib therapy. This test helps expose genome transpositions proving that the patient can benefit from Crizotinib treatment.
“The use of this new and reliable method for the express screening of cancer-related biomolecules has allowed scientists to design a unique panel of biomarkers that highlight the pre-cancerous stages of the tumor process (bio-predictors). Not only does this panel help select efficient breast cancer therapy methods, but it also diagnoses the disorder in its earliest stage,” Suchkov noted.
Examples of success
Metastatic melanoma is a dangerous health disorder, with most patients succumbing to it. The FDA’s decision to approve Vemurafenib helped 40-60 percent of patients with this diagnosis in clinical trials, which has tremendous implications. Vemurafenib has boosted the survival rate for the first time. However, this preparation does not effectively treat certain patients who must, therefore, undergo preliminary screening to see whether they have the required biomarker or not.
Another example has something to do with Brentuximab Vedotin used to treat Hodgkin’s lymphoma. Doctors have traditionally tried to treat such patients using autologous stem cells, but many of them eventually died. But Brentuximab Vedotin, which combines targeted monoclonal antibodies with an artificially created small molecule, guarantees a powerful curative effect, killing malignant cells and suppressing their propagation. Clinical tests showed a 73 percent positive effect in patients with Hodgkin’s lymphoma, with almost 32 percent of patients attaining complete remission.
The detection of certain bio-molecules in a patient’s semen drastically expedites high-precision early diagnostics of prostate cancer and helps identify the severity of the tumor process, Suchkov noted.
“It should be mentioned for comparison’s sake that doctors had to take biopsy samples from many patients who tested positive even if they had no prostate cancer. They had to undergo therapy for benign tumors that should have been left alone,” he explained.
The identification of such biomarkers as isolated transformed cells in the bloodstream helps evaluate the aggregate risk of metastases, monitor treatment efficiency and conduct pre-clinical diagnostics of concealed pre-cancer states. This new, informative and reliable biomarker for diagnosing and predicting various cancer forms can predict the survivability rates of patients with multistage metastatic cancer during treatment.
“New-generation biomarkers in the micro-RNA family being detected in the blood of those with breast cancer, lung cancer, intestinal cancer, etc. have become popular in the past few years. By using these biomarkers, doctors/chemotherapy experts gauge patients’ sensitivity toward various types of targeted therapy, including the latest combinatorial protocols. So far, this practice is widespread in the US and Europe, but is just being developed in Russia,” Suchkov said.
Looking for an ideal biomarker
According to experts, an ideal biomarker meets a number of criteria, depending on how it is used:
(a) it should be determined using non-invasive methods, and it should pinpoint a tumor prior to the first clinical symptoms;
(b) it should be sensitive to shifts in the tumor process, including a response to therapy or surgery;
(c) it should be quickly transferred from model systems into clinical practice as an interpretable parameter, without causing doubts among doctors.
It is necessary to develop a biomarker validation process and to standardize the procedure for preparing bio-samples for the purpose of introducing biomarkers. Reliable biomarker screening and evaluation systems need to be developed, becoming a long-term party to personalized and precision medicine.
The global biomarker technologies market continues to expand. This process is facilitated by a rapid increase in cancer cases, combined with successful diagnostics and treatment.
“It is essential that we search for new biomarkers, and the scale of this search should expand stage by stage, touching on ‘silent’ and apparently defunct genome spheres. For this purpose, we need to expand cooperation between academic and university science, bio-pharmaceutical and medical-diagnostic companies, while attracting venture and grant funds,” Suchkov believes.
In his opinion, individuals in all concerned groups should be involved in the decision-making process or should determine specific options for using intermediate and final research results. This is needed to develop totally new targeted medications.