Why are breast cancer genes dangerous for men?

Mutations of the BRCA1 and BRCA2 genes are generally considered to be the cause of breast cancer in women. However, for men they are dangerous.

Every time Pete Passanisi fastened his seat belt in a car, he felt uncomfortable. Where the nylon strap on the left touched his chest, pain arose.

At first, he thought he was pulling a muscle. Or is it heartburn. But in the end, his relatives convinced him to carefully feel his chest, and he found several cones, small and hard, like pieces of candy.

In December 2011, Passanisi, then 66, underwent a biopsy at a local hospital in Lake St. Louis (Missouri, USA) and the day after Christmas learned that the bumps are oncology, the second stage of breast cancer.

He underwent a mastectomy (removal of a part of the chest), and a little later – lymphadenectomy (removal of the lymph nodes).

“The seat belt saved his life,” says Annie, Passanisi’s daughter.

A few months after the operation of her father, the 27-year-old woman found out that she herself was the carrier of the same mutated gene, which led to the development of cancer in Pete Passanisi.

Today, Annie undergoes regular examinations, including MRI and mammography. “If the gene shows up, she will know about it at an early stage,” says Pete.

Mutations in the BRCA2 gene significantly increase the risk of developing breast and ovarian cancer.

The BRCA1 and BRCA2 genes are tumor suppressors; they are responsible for repairing damaged genes. When they stop doing it right, more and more errors occur in the DNA, which leads to cancer.

The risk of mutations in the BRCA1 and 2 genes is the same for women and men, but men are 10 times less likely to be screened for this.

One reason is the general misconception that such genes are tantamount to breast cancer (and many men do not believe that they have breast tissue).

Of course, men have fewer such tissues than women, and, accordingly, the risk of developing breast cancer is lower, even if they have BRCA2.

The fact, however, is that other dangers are associated with mutations of this gene.

Firstly, this poses a risk to the children of a person who has such a damaged gene.

The likelihood that a man will pass the mutated gene to his children is 50%, as is the case with women. If the daughters of such a person inherit this mutation, then by the age of 70 the chances of developing breast cancer in them are from 50 to 85%.

“If more men agreed to be screened, they would help women in their families take preventative measures, start regular tests,” says Julie Rani Nangia, director of the Breast Cancer Prevention Clinic at Houston Bay College of Medicine, Texas.

But the point is not only how the gene mutation affects the body of women. According to one recent study, men who have the BRCA2 gene are twice as likely to get prostate cancer than those who are free of such a gene.

In fact, 12% of men with metastatic prostate cancer carry the mutated BRCA gene. And this percentage is higher than that of women with breast cancer, carriers of such a gene. Prostate cancer in carriers of BRCA2 is much more often more aggressive.

“I believe that we should examine people with prostate cancer for gene mutations – to avoid the situation when the surgeon offers:” let’s wait and watch, “says Stephen Nerod, oncologist, head of the department of breast cancer research at the University of Toronto (Canada) “A conservative approach to the treatment of prostate cancer in a man with a BRCA gene mutation is contraindicated.”

On average, only 39% of men with a BRCA2 gene mutation manage to live more than five years after they are diagnosed with prostate cancer, but this, of course, largely depends on the level of medicine in the country where you live.

However, for men with prostate cancer and the damaged BRCA2 gene, there are much more effective treatments than for all other patients with prostate cancer. And if you start treatment early enough, the prognosis is quite optimistic.

The wider the examinations of men for possession of a mutated gene will be conducted, the easier it will be to detect cancer in the early stages of its development.

Ros Iles, a cancer geneticist at the Cancer Research Institute in London, recently oversaw a study of the risks of developing prostate cancer in patients with the BRCA2 gene. He urges all men with this gene after 40 years to regularly donate blood for analysis (PSA test) in order to control the state of the prostate.

“Our data show that men with germline cell mutations in the BRCA2 gene should undergo a PSA test every year so that doctors understand whether to offer them an MRI or prostate biopsy,” says Ils. “We hope that the European Association of Urology committee recommending for physicians, will take into account the data we have received. “

So far, in the UK, for example, it is officially recommended that only family members with a history of prostate, breast or ovarian cancer have a genetic test for BRCA gene mutations. No preventive measures, however, are provided.

Such measures could include combating the misconception that BRCA mutations increase the risk only for women, says Julie Rani Nangia.

Measures could be taken faster if doctors more often recommended studies to patients at risk. Unfortunately, therapists avoid recommending something that they themselves are not very good at.

But as genetic research becomes more accessible and cheaper, more and more people will resort to them to find out the risks to their health.

Such genetic tests in commercial clinics can be done without a doctor’s referral, which costs about $ 250.

Of course, such tests have their drawbacks. If their results are not analyzed by a knowledgeable geneticist, they may be misinterpreted.

In addition, if you are a carrier of a gene that is associated with a particular disease, this does not necessarily mean that you will definitely develop this disease.

Julie Rani Nangia, meanwhile, dreams of the day when genetic tests with an explanation of their results will be included in the services of the health system – regardless of whether there is a family history of the disease, and free of charge for the patient.

Then people like Pete Passanisi’s daughter will be more likely to stay healthy throughout their lives.

“On the one hand, I feel guilty and remorseful for having transmitted this gene to Annie,” Pete says. “But on the other hand, I’m glad she became aware of him. This gives her the opportunity to keep a close watch on her condition your health and find the right people in advance to help. ”

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You can read the original of this article in English on the website BBC Future.

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