Personalized Medicine

Personalized medicine (synonyms: personalized medicine, individualized medicine, individual medicine) follows the approach of an individual therapy based on the individual characteristics (individual genetic makeup of the individual) of the patient. Personalized Medicine is guided by the quote “diseases are as different as people”. Patients with an identical diagnosis do not receive the same therapy, but each receives an individual therapy.Each person has his or her own biochemical individuality. For example, drugs are metabolized differently by different individuals. But even clinically seemingly identical diseases can vary at the molecular level. The goal of personalized medicine is to enable people as individuals to lead optimal health-conscious lives. Targeted individualized diagnostic and therapeutic methods are available for this purpose.

The methods

Epigenetics, a specialty in biology/medicine, deals with cell characteristics (phenotype) that are inherited by daughter cells and are not fixed in the DNA sequence (genotype). Based on a medical expert system* (health risk analysis), epigenetic diagnostics analyzes lifestyle factors such as diet, stimulants, sports activity, environmental stress, as well as pre-existing conditions, surgeries, long-term medication, etc…. Genetic diagnostics includes genetic counseling, family history (pedigree analysis* ) and molecular genetic diagnostics (genetic testing, DNA analysis). The individual risk profile thus obtained is unique to each individual.

Individualized diagnostics

Epigenetic diagnostics

  • Nutrition – an accurate assessment of dietary habits (nutritional analysis* ) is necessary for the establishment of a personal risk profile, as the occurrence and progression of many epidemiologically relevant diseases, such as cardiovascular and tumor diseases, can be influenced by diet.
  • Semi-luxury food consumption – smoking and alcohol consumption, together with diet, are relevant risk factors for a variety of diseases. To create the individual health profile, the consumption of these noxious substances must be recorded and evaluated.
  • Sporting activity – an accurate assessment of physical activity / sporting activities (athlete analysis* ) is necessary for the creation of a personal risk profile, since the occurrence and progression of many cardiovascular diseases such as coronary heart disease (CHD) or myocardial infarction (heart attack) can be positively influenced by a sporting activity. Thus, the sporting activity is to be included as a protective factor in the individual health profile.
  • Environmental exposure – Pollutant exposures both on and off the job are part of the individual health profile. Pollutant loads are often underestimated in pathogenesis (disease development) and require precise diagnostics.

Genetic diagnostics

  • Family history (pedigree analysis* ) – for many diseases, such as tumor diseases like breast or pancreatic cancer, a close relationship is an important risk factor. Although the genetic risk cannot be influenced, the family history is of decisive importance, since, among other things, the frequency and timing of the start of preventive measures must be adjusted by the genetic risk. In the case of colon carcinoma, for example, preventive colonoscopy is based on the possible onset of disease in 1st-degree relatives. In order to establish a detailed and meaningful family history, a pedigree analysis over three generations is performed. Molecular genetic diagnostics allows the detection of genetic risk factors based on genetic tests (genetic testing): for example, in breast cancer, an increased risk can be detected by detecting the BRCA mutation (BRCA1, BRCA2, BRCA3 genes).
  • Pharmacogenomics – pharmacogenomics represents the genetic influence of the particular patient on the efficacy of drugs. Also, the effect of the dose of the drug on the body is often different for comparable body weight and function of the organs of metabolism.Through molecular genetic diagnostics in the sense of personalized medicine, differentiation is often possible at the molecular level in seemingly identical disease patterns.

Examples of the application of personalized medicine in oncology, immunology and rheumatology:The drugs listed below are only used if a genetic test has previously demonstrated the presence of the respective specific gene marker or a specific clinical picture (genetically defined special form).

  • Anastrozole (aromatase inhibitor; blocks the formation of estrogens in muscle and adipose tissue) – used in hormone-sensitive breast carcinoma (breast cancer).
  • Arsenic trioxide – indicated in promyelocytic leukemia (special form of acute myeloid leukemia with relatively good healing tendency).
  • Azathioprine (immunosuppressant) – use primarily in autoimmune diseases such as Crohn’s disease and ulcerative colitis as immunosuppressants.
  • Cetuximab – use of the monoclonal antibody primarily in EGFR-expressing metastatic colorectal cancer.
  • Dasatinib – indicated in chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL).
  • Exemestane (aromatase inhibitor) – use of the drug in hormone-sensitive breast carcinoma.
  • Fulvestrant (estrogen receptor antagonist) – primarily indicated in breast carcinoma (postmenopausal women with estrogen receptor positive, locally advanced or metastatic breast carcinoma).
  • Gefitinib (primarily inhibits EGFR family tyrosine kinases; epidermal growth factor receptor) – used in bronchial carcinoma.
  • Imatinib (tyrosine kinase inhibitor) – current use in chronic myeloid leukemia with evidence of Philadelphia chromosome (translocation of genetic material from chromosomes 9 and 22); studies indicate therapeutic success in pulmonary hypertension
  • Lapatinib (tyrosine kinase inhibitor) – suitable for the treatment of patients with HER2/neu positive breast carcinoma when tumor cells express increased levels of the receptors Erb1 (EGFR) and Erb2 (HER2/neu) on their surface, which is the case in approximately 25% of breast carcinoma patients
  • Letrozole (aromatase inhibitor) – indicated in hormone-sensitive breast carcinoma.
  • Maraviroc (selective inhibitor of chemokine receptor CCR5) – this drug is used for the treatment of HIV and acts as a selective inhibitor of chemokine receptor CCR5 and blocks the docking of HIV to human cells.
  • Tamoxifen (selective estrogen receptor modulator) – this estrogen receptor modulator is used in metastatic breast cancer
  • Trastuzumab (monoclonal antibody; binds to the epidermal growth factor receptor HER2/neu (human epidermal growth factor receptor) on the cell surface of tumor cells, inhibiting their growth) – the use of this monoclonal antibody is in breast and gastric carcinoma (breast and stomach cancer), among others.

Personalized medicine enables individualized therapy based on rational molecular and epigenetic data.