Interviews
Fat and cancer: Chilean scientists make important finding about this little-known relationship
- April 10, 2023
- Publicado por: ACCDIS
- Category: ACCDiS in Media News Featured news
The work was led by researchers from the Institute of Biomedical Sciences of the University of Chile, which demonstrates the link between adipose tissue and this disease.
For almost 50 years, the world’s population has been steadily increasing its levels of overweight or obese adults.
According to data from the World Health Organization (WHO), 28% of adults and 14% of adolescents in Chile were living with obesity in 2016, and it is estimated that these figures will increase to 36% and 17%, respectively by 2030.
A team of researchers from the Center for the Study of Exercise, Metabolism and Cancer (CEMC), Institute of Biomedical Sciences (ICBM), School of Medicine, University of Chile, conducted a review of all that is known to date about the processes that promote the development of cancer.
“We sought to establish based on information in the literature the connection with obesity, with adipose tissue,” explains Dr. Andrew FG Quest, part of the research team.
Adipose tissue
Adipose tissue dysfunction in obesity has been central to the understanding of how changes in its components, particularly adipocytes and macrophages, are involved in these processes.
In this review, the authors focused on how changes in adipose tissue in the face of excessive fat accumulation generate endocrine signals that promote cancer development.
In recent years, researchers have focused specifically on mechanisms of communication between tumor cells and their environment. How cancer cells communicate with their direct environment, but also how they connect systemically with the body, because they do so through the vesicle and that is important in processes such as metastasis.
Tumor cells are found in a tumor, and in a tumor there are many different cells, such as blood vessels, immune system cells, macrophages and also adipocytes. “We want to understand these processes specifically by focusing on the communication between these three components via the vesicle,” explains FG Quest.
In the research they looked at the adipose tissue outside the tumor where you can see the adipocytes, and these adipocytes when there are many, “it starts to grow a lot the tissue starts to grow macrophages and a communication is generated that makes this tissue more and more bad” adds the co-author.
In addition, after this process, a communication is generated between the adipose tissue and the potential tumor. So the researchers studied and analyzed how these cells communicate with the sector around the tumor in particular.
When there is an excess of tissue, it also begins to produce a series of factors that begin to attract macrophages and cause bad tissue to form and there are factors that can later influence tumor development.
“And beyond that, we tried to test or search in the literature for all those compounds with an antioxidant effect that managed to stop these signaling pathways in the tumor microenvironment,” says Layla Simón, co-author of the research.
Overweight or obese
Is someone who is overweight or obese, that makes fat more likely to generate cancer?
According to the review there are two ways. When you talk about the more distant or endocrine communication (when this adipose tissue or a person who is overweight or obese is damaged) inflammatory factors are generated that could make the person more prone to have cancer.
But there is also the case of the tumor microenvironment -which is when the person already has a tumor and the adipose tissue itself- and the same macrophages or lymphocytes “finally make this tumor or cancer advance in a certain way, perhaps more rapidly or lead to the effects of metastasis or complications,” explains Sofía Sanhueza, co-author.
However, “the most important thing for people to understand is that not everyone who is overweight starts to panic. It is just one more risk factor, but whether someone will develop cancer or not depends on a lot of other factors,” stresses Dr. Andrew.
The recommendation is, as always, to change habits and as prevention, to consume antioxidants that “have shown a very important potential in how to help in everything that has to do with this curricular mechanism and that can lower that which favors tumor development” adds the researcher.
Risk factor
At the end of 2021, for the first time cancer was the leading cause of death in Chile, with almost 28,500 deaths per year, equivalent to 26% of the total number of deaths (according to Vital Statistics 2019 of INE and Globocan 2021).
Given the magnitude of the problem and taking into account its association with chronic low-grade systemic inflammation, it is not surprising that obesity is now considered one of the main risk factors for the development of several chronic diseases, such as diabetes, cardiovascular problems and cancer.
Mariana Cifuentes, researcher at the Advanced Center for Chronic Diseases (ACCDiS ), Faculty of Medicine, U. of Chile, co-author, points out that there are several types of cancer that have increased with obesity.
That is why they are looking for the mechanisms that explain this, which is a finding of the observation of a large population “and that is why we are beginning to relate obesity from the adipose tissue far from the tumor and the cells of the adipose tissue that are inside the tumor or inside the tumor area”, she adds.
Hence the importance of investigating this association between adipose tissue and cancer, “it is important to understand why and hopefully then have the possibility of intervening” comments Dr. Andrew.
Sanhueza, ICBM researcher, comments that the main cancers associated with adipose tissue are:
- Breast cancer, which is a very graphic example because it is known that there is also adipose tissue in the breast, so the interaction is direct.
- Uterine cancer.
- Endometrial cancer.
- Digestive cancers, which are also closely related to obesity.
“There are several that are associated, it is said that approximately 15 types of cancer are associated with obesity, more or less”, adds the scientist.
Finally, in the development of cancer, inflammation is an extremely relevant component. So a direct link has been established between 15 types of cancer and obesity, “but I am sure that if we keep looking we will find more, that is not the limit,” assures Dr. FG Quest.
Likewise, it cannot be said that obese people are going to get cancer, “that cannot be said”, emphasizes the scientist.
This does not mean that a person with a lot of adipose tissue will develop cancer. “There have to be alterations that produce in the end that these cells converse in a way that is not convenient for us,” concludes Cifuentes.