Oncology and cancer therapy
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. There are over 100 types of cancers that affect humans. Normal cells control production of their growth signals, maintaining homeostasis of cell number and normal tissue architecture. Cancer cells deregulate this control system and therefore there are 6 characteristics describing them: sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis.
Cancer is generally not inherited, however some types – mainly breast, ovarian and colorectal cancer can run in families and can be inherited. Knowledge about the patient’s susceptibility to certain types of cancer can lead to preventative treatments and surveillance.
- Comprehensive NGS sequencing of all cancer causing genes
Genetic testing for specific mutations involved in the development of different types of cancer has revolutionized the way cancer is diagnosed and treated. As we are entering the era of personalized medicine, now each patient can receive individualized and customized treatment as well as predictions for the clinical outcome and the chances of cancer recurrence. Before personalized medicine, most patients with a specific type and stage of cancer received the same treatment. However, it became clear that some treatments worked better for some patients than for others. Personalized tumor medicine is used to learn about a person’s genetic makeup and how their tumor grows. Using this data, doctors hope to find prevention, screening, and treatment strategies that may be more effective. Another goal is to find treatments that cause fewer side effects than the standard options. By performing genetic tests on the cancer cells and on normal cells, doctors may be able to customize treatment to each patient’s needs.
There are currently three main approaches in the treatment of cancer: chemotherapy, targeted therapy and immunotherapy.
Chemotherapy is one of the strongest and oldest weapons in the fight against cancer. But although chemotherapy kills tumor cells, it also kills other cells in the body that are dividing rapidly, such as cells that make up the stomach, hair follicles, bone marrow cells, and so on, causing a number of side effects. Some people have an increased genetic predisposition to the side effects of chemotherapy and an increased probability of intoxication. The drugs tamoxifen, capecitabine, fluorouracil, tegafur, cisplatin, and pyrimidine analogues are tested in the precision chemotherapy tests.
- Procedure: By drawing venous blood, the genetic predisposition of patients to toxicity and adverse effects of chemotherapy is tested. After obtaining the genetic information, the oncologist can use them in the process of prescribing therapy.
Genetic information can serve to tailor therapy based on the unique molecular profile of a single tumor. In other words, every tumor tissue is heterogeneous and has its own unique “molecular profile” that can serve to establish the diagnosis and determine the right therapy.
- Procedure: With a biopsy a small sample is taken from the tumor tissue, it is afterwards sequenced (genetically “decoded”) and subsequently bioinformatically analyzed in order to determine the molecular profile of the cancer. In other words – the tumor’s weaknesses are revealed in order to target then with a particular therapy. After obtaining the genetic information, the oncologist can use them in the process of prescribing therapy. We can determine SNPs and copy number variants in a single test.
Cancer immunotherapy is one of the most encouraging approaches to the treatment of cancer in the past few years, and it aims to re-activate the patient’s own immune system and direct it to killing tumor cells. There are the so-called check-point inhibitors such as ipilimumab, nivolumab, pembrolizumab, atezolizumab, avelumab and durvalumab, which are of particular importance.
- Procedure: A biopsy is taken from a tumor tissue sample and analyzed for the presence of microsatellite instability (MSI). After obtaining the genetic information, the oncologist use them in the process of prescribing therapy. This test can be done together with detection of SNPs and CNVs.