26. 2. 2013 - Personalized medicine – tailored treatment

"If it were not for the great variability among individuals, medicine might as well be a science, not an art." Sir William Osler, 1892


According to the PubMed database the term "personalized medicine" was first used in 1971 as a part of an article written by Canadian W.M. Gibson, MD. It reflected very accurately the time of big discoveries in medicine during that period and their impact on the general status of physicians in society. Gibson vividly described his feelings as a young untrained doctor in 1939. There was often little hope of cure for many diseases currently described as controllable or curable but still, the medicine had one great benefit to offer – an individual approach to patient's problems and fears. He entitled his article with a simple question:"Can personalized medicine survive?" [1].erytritol_400

Today, a few decades later, we already know the answer: yes, it will not work without it, it is our future. Since the medicine made a big step forward and we can already save or treat incomparably more cases then whenever before, therefore we can afford such an answer. The only thing that can help us to move forward is just the personalized medicine (but in a somewhat different form than anyone have imagined forty years ago).

According to the Czech Society for personalized medicine and medical algorithms the personalized medicine is a multidisciplinary field, which is (at different levels) focusing on the optimization of therapeutic and diagnostic procedures for the individual patient using advanced informatic methods [2]. In layman's terms, tailored treatment would be a fitting expression. Precise and accurate diagnosis for a specific patient, in addition applied at the right time. We alreadz know, that from the view of genetic predisposition each person is unique. That results in plenty of different reactions to a single treatment (which can be pretty confusing when evaluating the final result). We can explain it even more expressively – lets say that using a classical processes 97% of all patients could be cured, but its a personalized medicine who raises the tempting question: how to cure the remaining 3% and where are the reasons for the therapy failure?.

To understand how the “personalization” of medicine works, it is necessary to explain two widely used scientific terms – pharmacogenomics and biomarker. The term pharmacogenomics has been first used in 1997 to set up a new discipline exploring the relationship between treatment response in different patiens, where their genetic information was taken into account [3]. In the context of pharmacogenetics, the biomarker is a substance presented in patient's body and its concentration depends primarily on genome. Due to specific variations in its concentration we may suggest to some individual differences or more likely ongoing pathological reactions and processes. Basicaly, there are two complementary approaches to this issue: a thorough analysis of the actual genome or of its external manifestations – biomarkers.

One of the examples of successful application of personalized medicine is warfarin, much discussed blood-thinning substance. According to statistics, the annual prescription of warfarin rised to almost 31 million (2004, [6]), while the risks associated with its use are significant. Since 2007, the U.S. Food and Drug Administration has recommended genotyping for all patients being assessed for therapy involving warfarin. Genotyping allows prescription of drug therapy regimens only to individuals expected to benefit from that specific drug at that specific dosage. Other promising example can be found in the field of oncology – the breast cancer or colorectal cancer receptors screening. With this procedure, an appropriate treatment for individual patients can be designed easily.

The are some interesting applications to be found also here in the Czech Republic. Scientists from the Institute of Chemical Technology in Prague are able to detect some serious diseases such as asthma or various types of lung cancers even before the full development of severe symptoms. And all of this thanks to easy analysis of selected biomarkers [5].

Personalized medicine is offering us a pleasantly bright future with hope of increasing the success of clinical treatment due to a greater understanding of the process of interaction of drugs and our bodies. However, we must never forget the ethics. Eventhough today it may seems that the most pressing tasks of our medical care system are the questions related with pharmacoeconomics and the ethical use of money in lowbudget effective pharmacotherapy, in future we will probably concentrate mainly on privacy issues. Who should have an access to our personal data? Employers? Insurance companies? Our MD? And just hypotheticaly, if there is a certain probability that we can be seriously ill, do we want to know the truth ourselves?

Author: Annamarie Némethová

 

Zdroje:

1. Gibson, W. Can personalized medicine survive?. Can Fam Physician 1971, 17 (8), 29–34.

2. http://www.cspmla.cz/pm-def

3. http://www.szu.cz/uploads/documents/CLC/OTLVS/olt/fartox.html

4. http://genetichealth.jax.org/personalized-medicine/what-is/applications.html

5. http://pvac.vscht.cz/pvac/projekty.php#21

6. http://www.ncbi.nlm.nih.gov/pubmed/17620536