Breast, endometrial, ovarian, colorectal, esophageal, kidney, pancreatic and prostate cancer are all types of cancer that obese patients are more likely to develop than patients with a healthy weight. Due to the stress created in the body by a high Body Mass Index (BMI), the measure used to diagnose obesity and morbid obesity, cancer is frequently a disease associated with obesity. In addition to cancer, there are a series of other comorbidities, the term used to designate these diseases related to another primary condition.
Development of Cancer and Obesity
Aproximately 34,000 new cases of cancer in men, the equivalent to 4%, and 50,500 in women, or 7%, are attributed every year annually to obesity in the United States, with the percentage varying according to the type of cancer and with endometrial cancer and esophageal adenocarcinoma leading the list. There are a series of factors that contribute to the high risk of developing cancer as a result of obesity, starting with the excess estrogen produced by fat tissue, which is associated with breast, endometrial and other cancer types.
Fat cells are responsible for the production of estrogen, as well as of other hormones, including adipokines and leptin. High levels of adipokines influence the cell growth, while leptin, also known as the “satiety hormone,” promotes cell proliferation. In addition, patients who suffer from obesity usually have increased levels of insulin in the blood, resulting in insulin resistance, a problem that causes not only diabetes, but also certain types of cancer.
Cancer and Obesity Prevention
Research studies about the health and economic effects of obesity reveal that about 500,000 additional cancer cases are expected in the United States by 2030. However, even a reduction of BMI by less than 5% may help decrease the risk of cancer in obese patients and prevent approximately 100,000 new cases of cancer. Healthy diet and regular physical activity remain the most important methods to prevent both obesity and associated diseases like cancer.
Since obesity is a risk factor associated with cancer, regular visits to the physician and screening can improve prevention or help patients find the disease early. Despite the fact that not all cancers are preventable, avoiding other risks such as smoking may also contribute to cancer and obesity. Following menopause, women also have additional probability of developing certain types of cancer, a factor that should be particularly considered by obese patients.
Cancer Treatment by Obese Patients
Cancer treatment is a widely studied topic and there are a series of therapeutic options available, including surgery, chemotherapy, radiation therapy, targeted therapy, immunotherapy, hyperthermia, stem cell transplant and photodynamic therapy, all of which are used according to the type of cancer, patients and other individual characteristics. However, obesity has serious implications in the treatment of cancer, as well as in recovery.
The study “How Obesity Complicates Cancer Treatment,” published in 2012 at the Oncology Times journal, raises a series of questions regarding the topic. The investigators start by noting that there is a lack of studies including obese patients, which leads to the dosage dilemma. The problem is that oncologists need to almost guess what the optimal dosage is for obese patients. Similarly, surgery bring with it additional risks for obese patients, while the effects of radiotherapy are also not certain given the presence of excess fat tissue.