Dr. Pilar Carvallo: The relevance of information, investment and research around breast cancer in Chile

Dr. Pilar Carvallo: The relevance of information, investment and research around breast cancer in Chile

During the year 2020, about 2.2 million cases of breast cancer were reported, becoming the most common of the cancers within the range of this terrible disease that claims hundreds of thousands of lives every year around the world.

According to the World Health Organization: "About one in 12 women will get breast cancer throughout their lives," with breast cancer being "the leading cause of mortality in women [...] about 685,000 women died as a result of this disease.", (Source: https://www.who.int/es/news-room/fact-sheets/detail/breast-cancer).

In Chile the numbers are not encouraging, in fact, according to statistics provided by the National Cancer Plan 2018-2028, of every 100,000 women, 16,600 die from malignant breast cancer tumors (https://www.minsal.cl/wp-content/uploads/2019/01/2019.01.23_PLAN-NACIONAL-DE-CANCER_web.pdf). Under this scenario, Dr. Pilar Carvallo, biologist at the University of Chile, Doctor of Science with a mention in Biology from the same house of studies and Professor of the Faculty of Biological Sciences of the Pontifical Catholic University of Chile, has studied breast cancer for decades from a genetic perspective, developing novel molecular tools that allow the early detection of this disease.

Some time ago Dr. Carvallo announced with her research team the fruit of an enormous work of more than two decades, which triggered the identification of 9 recurrent mutations among Chilean patients with hereditary breast cancer. These 9 mutations are in the BRCA1 and BRCA2 genes – the most linked to this type of cancer – and confer a risk of breast cancer between 50-57%. The identification of these 9 recurrent and founding mutations in the Chilean population generates a great opportunity to carry out genetic studies at a very low cost, easy methodology and simple analysis. These 9 mutations are present in 80% of Chilean women who are carriers of a mutation in one of these genes. The identification of these mutations in patients with breast cancer contributes to a greater and better therapy for the patient, and for their relatives the possibility of early detection of a cancer and / or preventive prophylactic surgeries if they are carriers of the familial mutation. "With these nine founding mutations we decided to develop a diagnostic kit based on fluorescent probes. In the process, we work in collaboration with the Base Hospital of Valdivia, in order to bring this genetic technology closer to public health," says the academic.

To get an idea, the kit generated by Dr. Carvallo has an approximate cost in reagents that is 10 to 20 times lower per patient than the value of DNA sequencing offered by foreign companies. "It should be noted that sequencing methods have varied costs, especially North American and European companies that have a high interest in the population of Latin American immigrants; for now, that is where the freedom of the market comes in and it is difficult to establish a regulation of prices. In addition to this problem, there is also vague regulation at the international level regarding companies that offer not only studies, but genetic products for complex diseases, such as Alzheimer's. That is, when they point out to the patient that he has a predisposition to a huge list of diseases, it is not so real, since what is detected are genetic variants that alone do not constitute risk, or they are polymorphisms that, normally, fall into non-functional regions of the genes, "he explains. Therefore, these genetic variants, given as a risk by the companies that do these studies, do not determine a real predisposition to a disease since the vast majority does not generate functional changes.

In that sense, for example, women with hereditary breast cancer, which border on 35% of all cases of breast cancer, meet certain characteristics and family criteria that help the realization of the diagnosis. "In Chile, 20% of women with hereditary breast cancer, with a family history, have a mutation in the BRCA1 or BRCA2 genes. Also 10% of women with breast cancer, who have no family history, but whose age of diagnosis is before 45 years, have mutation in BRCA1 or BRCA2, as well as 15% of women with bilateral breast cancer. Another gene involved is PALB2, whose mutations present a moderate risk in the development of the disease, and the incidence of mutations in this gene is very low, about 2%," he says. On the other hand, the academic explains that: "Years ago it was reported that only 10% of women with breast cancer corresponded to hereditary cases, and that was because, at that time, it was considered kinship only in the first degree, to define hereditary, that is: history of cancer of both parents, siblings or children, leaving aside other types of relatives such as grandparents and uncles, which is genetically very relevant." –Currently the kinship of a patient with hereditary cancer is consulted up to the second degree, therefore the increase in the percentage (from 10 to 35%). It is important to emphasize that DNA is inherited by the father and mother, therefore, the same goes for mutations that confer a high risk of breast cancer. For that reason, family history should be analyzed on both sides of the family. It is also important to note that mutations in BRCA1 and BRCA2 confer risk of ovarian cancer (25-30%), prostate (10%), and pancreas (10%), among others.

October: Breast Cancer Month

October globally is known as the month in which the relevance of breast cancer is celebrated and raised. During this period, prevention campaigns are developed in which the attendance of women to the doctor is stimulated to perform examinations such as the Pap smear or actions such as self-examination through palpations. However, and like many activities that were previously developed normally, the campaigns were not seen with as much preponderance as in previous years, and much of this has to do with the current COVID-19 pandemic, which tarnished the efforts of the community linked to the prevention, detection and care of breast cancer.

Finally, in countries like ours, in which investment in scientific research ranges between 0.3 and 0.4% of the Gross Domestic Product, financing is presented as a serious problem, especially talking about molecular tools that would be used massively in patients. "The diagnostic kit for the 9 founder mutations, despite being low cost compared to the methodologies currently offered, and having a detection capacity of 80% of women carrying a mutation in BRCA1 or BRCA2, there is still no possibility of being funded as a tool for clinical use in the public system. In that sense, it is very relevant to make it clear that men and women who have access to this information will begin to save lives, since with that information they will be able to act in time. That is why the importance of investment and financing", concludes Dr. Carvallo.