Obesity and cancer

By Alexander Thomas, MBS 2019 Geisinger Commonwealth School of Medicine

Mentor: Darina Lazarova, PhD



Obesity and cancer are two health topics that anyone in the year 2019 is familiar with. All of us know at least one individual who has been affected by these conditions. The physiology behind obesity and cancer are intricate, and the connection between them is a focus of current research. Whereas a small percentage of cancer is due to genetics, there is a significant link between certain socioeconomic factors and the progression of cancer.

Currently, over 70% of the American population is overweight or obese. Among the American adults, approximately 30% are considered obese. Obesity is measured by means of a Body Mass Index, a scale that takes a patient’s height and weight into consideration. A patient having a BMI of 30 or above is categorized as obese. A healthy weight individual’s BMI ranges between 18.5 to 24.9.

We are all aware that obesity can cause many health problems. These can range from short term lack of mobility to long term coronary heart disease. However, there is a lack of public knowledge regarding the connection between obesity and cancer. 

The connection between obesity and increased cancer progression might be due to at least three causes. The first is that the excess body fat leads to inflammation within the body. Increased inflammation spurs the production of cytokines, which can induce the growth of blood vessels. These blood vessels supply tumors with the oxygen and nutrients needed for cell growth. The inflammation can also cause cells to become insulin resistant, meaning they no longer can effectively respond to insulin. Because of this, blood sugar levels rise, causing the pancreas to release an excess of insulin. Finally, the level of estrogen, a steroid hormone found in both men and women, can have a direct effect on cancer progression. Estrogen can act upon cells and cause them to multiply at higher than usual pace. These three mechanisms: inflammation, excess insulin production, and excess estrogen can cause cells to multiply faster. When you have cells dividing at such an excess rate and quantity, the chances of harmful DNA damage increase greatly.

So, what can be done to reverse this trend? First, many Americans do not realize that they are overweight in the first place. I believe that there needs to be a much greater open dialogue between a patient and their physician in understanding the risks that obesity brings. If someone who is currently obese wants to make a lifestyle change, they need to be equipped with the proper steps to be successful. Underserved areas within our country currently have the greatest need for resources to combat obesity. This situation might be directly related to the lack of available fresh produce and open public spaces for individuals to be active on a daily basis. Local government bodies can take a greater initiative in making healthy meal options available in community pantries; they can also emphasize the need for more stores that sell produce while limiting the number of fast food establishments within an area. Making a conscious decision about the quantity and quality of calories that we consume will also increase our chances of a healthy future.