Breast cancer is a major cause of concern to many; since almost 40000 women die every year in USA alone die from it every year. With such high incidence of breast cancer it is but natural to look into all the causes and hence a number of studies have been carried out during the past few years. Amongst many other reasons, they also indicate a strong link between body weight and occurrence of breast cancer. These studies establish a direct link of cancer with obesity.
While and maybe a lack of clinching proof that it is obesity that directly leads to cancer many studies have pointed out that it has at least an indirect effect and positively seems to lead to recurrence of cancer breast cancer. Some of the older studies also show that more obese women are seen to have a tumor size that is larger than those with the normal breast size, pointing to a higher rate of nodal and lymphatic involvement.
After going through almost 50 case studies that try to establish a link between the body weight to breast cancer, recent analysis shows that overall higher number of obese women are diagnosed with breast cancer than those with normal weight. Recent ADEBAR studies also show that the incidences of recurrence of breast cancer in obese women are much higher than those who had a BMI which was less than 25.
Since obesity is directly linked with the type of food that we eat – other nutritional factors too come into play. Thus the lesser intake of fiber as well as other nutritional food items may be responsible indirectly in triggering insulin resistance as well as excessive estrogen secretions. The study thus indicates that hyper-insulinemia often influences the growth of tumors cells.
During the study of molecular links and obesity in the cases of breast cancer of women, it was indicated that obese, post-menopausal women have higher chances of recurrence of cancer due to the high estrogen levels. This, combined with higher insulin resistance leads to increase in the amount of mitogens in the body leading to higher incidences of breast cancer. This also affirms the hypothesis that obesity may be directly linked to endocrinal tumor.
There is now shifting evidence with research showing that Adipocytes, which are present in the human breast cells; and were earlier viewed as the energy storing cell, are akin to dynamic endocrine cells that secrete a variety of polypeptides, cytokines, and other hormone like molecules.
Quite often, the spread of cancer in the breast takes place through basement membranes when adipocytes allow the paracrine interactions with the tissues to take place. There have been studies which indicate that the adipose tissue, which secretes adipokines, can directly lead to growth of timorous cells.
Animal experiments in mice also point to the fact that adipokines could tinker with the genes involved in the infiltration, metastasis, and growth of breast-cancer cells when given the right environment. They also simultaneously hindered the p18 and BARD1, which are responsible for suppressing tumor and act like a cell cycle inhibitors. This study came out with direct evidence of adipocytes leading to aggressive growth of tumors in the cases of breast cancer. It further goes on to establish link of the role of the many other inflammatory cytokines.
Obesity is a source of many diseases in humans and with every passing day, more and more evidence points to it leading to manifestations of many diseases; breast cancer is one of them. Inflammatory cytokines play a major role in the onset as well as recurrence of breast cancer and there is a lot of research that is taking place to pin it down as one major cause of breast cancer.