Personalized medicine is a medical sculpt that proposes the customization of healthcare, with decisions and practices being tailored to the individual patient by use of genetic or other information.
Scenario from genetics and beyond
Traditional clinical diagnosis and management emphasizes on the individual patient's clinical symptoms, medical and
family history, and data from laboratories to diagnose and treat their illnesses. This is often an immediate approach to treatment, i.e., treatment starts after the signs and symptoms appear.
Advances in human genetics have helped us enabling a more detailed understanding of the effects of genetics in disease. The field of proteomics, or the comprehensive analysis and characterization of all of the proteins encoded by the human genome, may ultimately have a major impact on medicine. This is because while the DNA genome is the information archive, it is the proteins that do the work of the cell, not genes.
Important biological functions like cell growth, death, cellular movement and localization, differentiation, etc. are controlled by a process called signal transduction. This process is nearly entirely epi-genetic and governed by protein enzyme activity. Diseases such as cancer, while based on genomic mutations, are functionally apparent as dysfunctional protein signal transduction. Pharmaceutical interventions aim to modulate the aberrant protein activity, not genetic defect.
Historically, the pharmaceutical industry has developed medications based on empirical observations and more recently, known disease mechanisms.
Since the late 1990’s, the advent of research using biobanks has brought advances in molecular biology, technologies
including proteomics, metabolomic analysis, genetic testing, and molecular medicine. It is hoped that information about a patient's proteomic, genetic and metabolic profile could be used to tailor medical care to cater his needs. In the future, tissue-derived molecular information might be combined with an individual's personal medical history, family history, and data from imaging, and other laboratory tests to develop more effective treatments for a wider variety of conditions.
Oncology is a field of medicine with a long history of classifying tumor stages and subtypes based on anatomic and
pathologic findings. This approach includes histological examination of tumor specimens from individual patients (such as HER2/NEU in breast cancer) to look for markers associated with prognosis and likely treatment responses. Thus, "personalized medicine" was in practice long before the term was coined. New molecular testing methods have enabled an extension of this approach to include testing for global gene, protein, and protein pathway activation expression profiles and/or somatic mutations in cancer cells from patients in order to better define the prognosis in these patients and to suggest treatment options that are most likely to succeed.
Examples of personalized cancer management include:
Testing for disease-causing mutations in the BRCA1 and BRCA2 genes, which are implicated in familial breast and
ovarian cancer syndromes. Discovery of a disease-causing mutation in a family can inform "at-risk" individuals as to whether they are at higher risk for cancer and may prompt individualized prophylactic therapy. More detailed molecular stratification of breast tumors may pave the way for future tailored treatments.
Minimal residual disease (MRD) tests are used to quantify residual cancer, enabling detection of tumor markers before physical signs and symptoms return. This assists physicians in making clinical decisions sooner than previously possible.
Targeted therapy is the use of medications designed to target aberrant molecular pathways in a subset of patients with a given cancer type. For example, trastuzumab (marketed as Herceptin) is used in the treatment of women with breast cancer in which HER2 protein is over expressed.
Nowadays with the increasing knowledge of human genome, antibiotics can be developed such that they are sensitive
to a specific microorganism. One of the applications is to treat urinary tract infections (UTI). Here in by studying the genome of the patient, it is possible to optimize the efficacy of the drug for the patient. The technologies supporting personalized medicines could enable the pharmaceutical industry to develop a more efficient drug, based on the latest research on disease pathophysiology and genetic risk factors.
For healthcare providers, personalized medicine offers the potential to improve the quality of care, through more precise diagnostics, better therapies, and access to more accurate and up-to-date patient data. Physicians will require a solid background in genomics and proteomics to make the best use of the new data.