Scientists have discovered more than 350 DNA errors that make women prone to developing breast cancer.
A study of 200,000 patients identified 352 genetic mutations that could affect whether a person develops the deadly disease.
Experts from Cambridge University, who conducted the research, believe that these changes can warp as many as 190 genes.
Previously, fewer than 40 genes were recognized as risk-enhancing for breast cancer.
The findings can help determine which women are predisposed to develop the disease, so that they can be followed better than others.
With more than 55,000 new cases per year, breast cancer is the most common type of the disease in the UK. In the US it affects 270,000 people every year.
DNA, the blueprint for the human body, contains genetic information and has all the instructions that a living organism needs to grow, reproduce and function.
There are more than 350 ‘errors’ in the DNA that make women susceptible to developing breast cancer, research from Cambridge University suggests (stock)
Humans contain between 20,000 and 25,000 genes – 99.9 percent of them are identical from person to person.
The other 0.1 percent of genetic variants makes people unique and changes their hair color, skin color or even the shape of their face.
But these changes can also have serious negative effects, including increasing the susceptibility of individuals to diseases.
Most diseases, including breast cancer, are complex and are not caused by a single genetic variant or gene.
WHAT IS BREAST CANCER?
Breast cancer is one of the most common cancers in the world. Every year there are more than 55,000 new cases in the UK and the disease claims the lives of 11,500 women. In the US, it hits 266,000 each year and kills 40,000. But what causes it and how can it be treated?
What is breast cancer?
Breast cancer originates from a cancer cell that develops in the mucosa of a duct or lobule in one of the breasts.
When breast cancer has spread into the surrounding breast tissue, this is called an “invasive” breast cancer. Some people are diagnosed with ‘carcinoma in situ’, where no cancer cells have grown beyond the canal or the lobes.
Most cases develop in women older than 50 years, but younger women are sometimes affected. Breast cancer can develop in men, although this is rare.
Staging means how large the cancer is and whether it has spread. Stage 1 is the earliest stage and stage 4 means that the cancer has spread to another part of the body.
The cancer cells are sorted from low, which means slow growth, to high, which grows fast. High-quality cancers return more often after they have been treated for the first time.
What causes breast cancer?
A cancerous tumor starts with one abnormal cell. The exact reason why a cell becomes cancer is unclear. It is thought that something damages or changes certain genes in the cell. This makes the cell abnormal and multiplies ‘out of control’.
Although breast cancer can develop for no apparent reason, there are some risk factors that can increase the risk of breast cancer, such as genetics.
What are the symptoms of breast cancer?
The usual first symptom is a painless lump in the breast, although most breast lumps are not cancerous and are fluid-filled cysts that are benign.
The first place that breast cancer usually spreads to is the lymph nodes in the armpit. If this happens, you will get a swelling or lump in the armpit.
Instead, the combination of a number works together to increase the chance.
In the latest study, researchers compared the DNA of 110,000 breast cancer patients with that of 90,000 healthy people.
They identified 352 variants that could increase the risk of the deadly disease. It is not yet clear how many genes this target is, but the researchers estimate that it is 191.
Of the newly discovered genetic variants, one third is susceptible to women in developing hormone-sensitive breast cancer.
This type of disease occurs in four out of five breast cancer patients and occurs when cancer cells grow in response to the hormone estrogen.
Fifteen percent of the genetic variants predispose women for the more difficult-to-treat type, called estrogen-receptor negative breast cancer.
Chief author of the study, Dr. Alison Dunning said, “This incredible amount of newly discovered breast cancer genes offers us many more genes to work on, most of which have not been studied before.
“It will help us build a much more detailed picture of how breast cancer develops and develops.
“But the large number of genes that are now known to play a role emphasizes how complex the disease is.”
In most cases, the genetic change affected gene expression rather than changing the type of protein itself.
Nine different variants, for example, regulate the same gene, the estrogen receptor (ESR1) gene.
Many other variants affect sites in the DNA where the estrogen receptor protein binds and in turn regulates other genes.
This underlines the importance of the ESR1 gene and the protein product, the estrogen receptor, in the development of breast cancer.
Although each genetic variant only increases the risk of developing breast cancer by a very small amount, the researchers say that, taken together, this will allow them to ‘refine’ genetic tests and give women a much clearer picture of their genetic risk. to give.
This allows doctors and clinicians to advise on the best strategy to reduce their risk and prevent the onset of the disease.
Co-author Dr. Laura Fachal of the Wellcome Sanger Institute in Cambridge said: ‘We know from previous studies that variants in our DNA contribute to the risk of breast cancer, but scientists have rarely been able to identify which genes are involved.
“We need this information because it gives us a better idea of what drives the disease and therefore how we can treat it or even prevent it.”
The results, published today in the journal Nature Genetics, offer the most comprehensive chart of risk variants for breast cancer to date.