Personalized treatment in cancer

Cancer is a global health problem that occurs in all ages, although it is more frequent in adults. Each year 12.7 million people are diagnosed with cancer and 7.6 million die from this disease whose origin is the combination of genetic factors and the environment Medical Syndromes.

The DNA that forms the human genome is made up of 3,200 million units of which there are four types Adenine (A), Guanine (G), Thymine (T) and Cytosine (C). The paragraphs or genes of this long chain contain the information for each of the functions carried out by the cells and the organism as a whole. The tissues formed by cells have structure and specific functions that contribute to the functioning of the human body. Thus, when the cells of a tissue are under the control of a healthy DNA, the tissues keep their natural anatomy. However, when DNA accumulates errors in its reading, the functions of a tissue are lost, as well as its structure, giving rise to tumors.

Humans share 99.9% of the sequence of the human genome. However, there are several million letters dotted along the chain that can vary generating the diversity of the species. Changes in the DNA sequence are known as mutations and could be equated to misspellings in a text. There are mutations that confer predisposition to cancer. For example, some mutations in the BRCA1 and BRCA2 genes confer predisposition to breast cancer. Thus, when these or other mutations accumulate and combine with certain stimuli from the environment, the risk of suffering from this disease increases. Therefore, in some populations where these mutations are found more frequently, as in the Ashkenazi population, these tests are used to detect women at risk of breast cancer,

Some variations in DNA define how a cancer patient will respond to treatment. This is the case of the response to 6-Mercaptopurine (Purinetol), a drug that is used with great efficacy in the treatment of children with Acute Lymphoblastic Leukemia (ALL). However, approximately one in every 300 patients develops an adverse response to the medication, putting their lives at risk. Four variations of a single letter in the TMPT gene are currently known, the combination of which allows identifying the child who will have the potentially fatal response. This test is done routinely in patients with ALL in industrialized countries.

The Food and Drug Administration (FDA) of the United States has published a list of about 30 anti-cancer drugs whose effects are determined by variations in DNA. Consequently, it requires including in the medicine box the information on DNA studies that are recommended to decide the use and dose of these drugs in each patient.

Although cancer treatments are increasingly effective, it is not uncommon for two apparently identical tumors, even under a microscope, to respond differently to the same treatment. This is largely because mutations in the DNA of tumors are different. For this reason, knowing the DNA of tumors and the way in which their genes “turn on” and “off” is increasingly useful in order to achieve more effective treatments. For example, in patients with Chronic Myeloid Leukemia, the presence of the so-called Philadelphia Chromosome generated by an anomalous connection between two genes is routinely sought. When present, treatment with Imatinib (Gleevec) is very effective. In breast and stomach cancer, when the cells contain large amounts of the HER2 gene product, Trastuzumab (Herceptin) is an appropriate option because it binds selectively to HER2 inhibiting the proliferation of these cells. Similarly, the use of Erlotinib (Tarceva) has been recommended for the treatment of non-small cell lung cancers, pancreatic cancers and other tissues when its EGFR gene is expressed at levels above normal, or contains mutations. On the other hand, thyroid, colon and melanoma tumors that contain the V600 mutation in their BRAF gene generate a protein that stimulates the growth and reproduction of malignant cells. The detection of this mutation invites us to consider Vemurafenib (Zelboraf) in the treatment. The use of Erlotinib (Tarceva) has been recommended for the treatment of non-small cell lung cancers, pancreatic cancers and other tissues when its EGFR gene is expressed at levels above normal, or contains mutations. On the other hand, thyroid, colon and melanoma tumors that contain the V600 mutation in their BRAF gene generate a protein that stimulates the growth and reproduction of malignant cells. The detection of this mutation invites us to consider Vemurafenib (Zelboraf) in the treatment. The use of Erlotinib (Tarceva) has been recommended for the treatment of non-small cell lung cancers, pancreatic cancers and other tissues when its EGFR gene is expressed at levels above normal, or contains mutations. On the other hand, thyroid, colon and melanoma tumors that contain the V600 mutation in their BRAF gene, generate a protein that stimulates the growth and reproduction of malignant cells. The detection of this mutation invites us to consider Vemurafenib (Zelboraf) in the treatment. They generate a protein that stimulates the growth and reproduction of malignant cells. The detection of this mutation invites us to consider Vemurafenib (Zelboraf) in the treatment. they generate a protein that stimulates the growth and reproduction of malignant cells. The detection of this mutation invites us to consider Vemurafenib (Zelboraf) in the treatment.

The detection of these useful biomarkers in the treatment of cancer is an initial sample of the great power that innovation has around the human genome to improve health care.