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Obesity: What's the Cancer Connection?
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Does excess weight pose a cancer related health risk for women? Read more to find out.
On my most recent visit to the oncologist, I was surprised when he mentioned something about my weight. I’m not obese, but I do admit I have a few extra pounds on my carriage. At almost 60 years of age with no thyroid gland, I know my metabolism has slowed dramatically since having my four children. I do my best to watch what I eat and I make sure I exercise daily, but even with my best efforts, the weight doesn’t slip off easily.
I questioned the doctor about his comment. He’d said, “You really need to watch your weight.” I asked what he meant by that and he explained that since I was post-menopausal and my breast cancer had spread to my lymph nodes, it was important to keep an eye on my weight. I still didn’t understand what he was trying to say so I probed further. I asked what carrying a few extra pounds had to do with my risk for recurrence of breast cancer. He sat me down and explained my cancer, my stage 3B invasive ductal carcinoma, was fed by estrogen and progesterone. Although I’d had the cancer surgically removed from my body, there was still the possibility of it returning, especially since it had traveled into my lymphatic system. He also reminded me I’d chosen to forego the anti-hormone therapy after trying Arimidex, Aromasin and Tamoxifen with extreme side effects. Those anti-hormone drugs would have greatly reduced the production of estrogen in my body. Without the assistance of the medication, it was important that I do what I could to keep my estrogen levels low.
I still didn’t understand what he was talking about and asked him to speak to me in plain English. Finally, he said, “Fat cells produce estrogen. The more fat you have on your body, the more estrogen your body is making.” Now I understood. I made a mental note to do some research on the subject when I got home but I was also going to work on my diet.
Obesity. What do you think of when you first hear the word? Do you think of the television show that follows morbidly obese people on their journey to lose weight? Or do you think of someone you know who’s carrying a few extra pounds more than they ought to be carrying? To many of us, obesity sounds like a dirty word. It’s a word that instantly connotes an unhealthy body state. But excess body fat isn’t only unsightly to look at, it also poses many health risks. Obesity is a growing health concern in our country and around the world. Americans like to eat and most of us eat well. Even after a very satisfying meal, many of us ingest an unhealthy amount of unnecessary calories by choosing dessert after every meal. We even eat when we aren’t hungry. People from other countries look at Americans and are astounded at our size.
In 2010, First Lady Michelle Obama was so concerned with the childhood obesity epidemic in America that she implemented a program called, “Let’s Move.” In an effort to get America’s overweight and underactive children moving, Mrs. Obama stressed the importance of a healthy diet coupled with exercise. President Obama followed suit forming a task force aimed at the problem. There were five goals associated with the plan: to create a healthy start for children, to empower parents and caregivers, to provide healthy food in schools, to improve access to healthy, affordable foods, and to increase physical activity. The task force hoped to reduce the childhood obesity rate down to five percent by the year 2030. Obesity is not only a problem among our children. In every city and state across America, we find overweight individuals.
As I began to research information related to breast cancer and obesity, I found many articles and medical journals. Almost all of the articles shared the same information. Of the information I found, most medical professionals agreed that excess body weight was linked to an increased risk of postmenopausal breast cancer, and evidence suggests that obesity is also associated with a poor prognosis in women diagnosed with early-stage breast cancer. Studies demonstrated that women who carry excess weight at the time of a breast cancer diagnosis are at increased risk of cancer recurrence and death compared to those of thinner women. Some evidence suggested women who gained weight shortly after a breast cancer diagnosis may have increased odds of poor outcomes.
Obesity has been proven to contribute to many health issues such as diabetes, heart attack, stroke, high blood pressure, gall bladder disease, sleep apnea and more. Most doctors watch their patients’ weight closely and have them weigh in at every visit. Not only are they concerned about their weight, they also keep close tabs on their patients’ body mass index. The body mass index, also known as the BMI, is calculated by dividing a person’s body weight (in kilograms) by their height (in meters) squared (commonly expressed as kg/m2). The body mass index gives a more accurate measure of obesity than weight alone. A body mass index under 18.5 is indicative of a person being underweight while a body mass index of 40 or higher indicates severe obesity. BMI charts can be found readily on the internet and are easy to use for assessing one’s personal status.
Recently, there have been studies conducted on the connection between obesity and breast cancer. According to an article published by cancer.gov, “Obese people often have chronic low-level inflammation, which can, over time, cause DNA damage that leads to cancer. Overweight and obese individuals are more likely than normal-weight individuals to have conditions or disorders that are linked to or that cause chronic local inflammation and that are risk factors for certain cancers…Fat tissue (also called adipose tissue) produces excess amounts of estrogen, high levels of which have been associated with increased risks of breast, endometrial, ovarian, and some other cancers.”
The World Cancer Research Fund estimates about 20 percent of all cancers diagnosed in the United States are related to body fatness, physical inactivity, excess alcohol consumption and/or poor nutrition, and could also be prevented. These factors are all related and may contribute to cancer risk, but body weight seems to have the strongest evidence linking it to cancer. Excess body weight contributes to as many as one out of every five of all cancer-related deaths.
Being obese is clearly linked with an increased risk of many types of cancers, including the following:
Breast cancer (postmenopausal)
Colon or rectal cancer
Endometrial cancer
Esophageal cancer
Renal cancer
Pancreatic cancer
Being overweight or obese might also pose risk for other types of cancers including gallbladder cancer, liver cancer, non-Hodgkin lymphoma, multiple myeloma, cervical cancer, ovarian cancer or various prostate cancers.
The relationship between body weight and cancer are complicated and not fully understood. Some studies have found women who are overweight after menopause have an increased risk for developing breast cancer but those who are overweight before menopause do not seem to have an increased risk. Carrying excess weight during childhood might pose a stronger cancer risk factor for women than for those who gain weight later in life.
In another article, “Obesity, however measured, adversely affects the development and prognosis of breast cancer. There is ample data to suggest that obese and physically inactive women with breast cancer may have poorer survival compared with lighter weight and more active women. Obesity is one of the few risk factors for breast cancer that can be modified throughout life.”
After listening to the concerns of my oncologist and after reading information about the subject, I am even more concerned about excess weight than ever before. As a breast cancer survivor, it’s my responsibility to do what I can to better my health. If it means dropping a few pounds so I can live longer, you’d better believe that’s exactly what I’m going to do. I don’t ever want to face a recurrence of cancer. The first time around was hard enough!
Please take time to assess your body mass index. If you find you fall into the overweight or obese category, discuss it with your doctor, especially if you’ve already been diagnosed with breast cancer. I’ve listed a link here and in the resources below for a free online calculation tool.
Resources:
https://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/obesity-fact-sheet#q1
https://www.ncbi.nlm.nih.gov/pubmed/22106549
https://www.ncbi.nlm.nih.gov/pubmed/16945118
http://onlinelibrary.wiley.com/doi/10.1111/j.1471-0528.2006.01021.x/full
https://www.cdc.gov/healthyweight/effects/index.html
https://www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm
