A new American report warns about the role of obesity in the onset of cancer. Nearly 40% of all cancers are related to obesity, according to new research, which suggests that these tumors would be preventable if the weight were kept under control. The report, titled Vital Signs, was compiled by researchers from the Center for Disease Control and Prevention (CDC) in collaboration with researchers from the National Cancer Institute. Professor C. Brooke Steele, of the CDC Division for Cancer Prevention and control, is the first author and correspondent of the report. The results are particularly important given the alarming statistics on obesity in the United States. Between 2013 and 2014, CDC note, as many as 2 in 3 adults were deemed overweight or obese.
Overweight is defined as a body mass index (BMI) between 25 and 29.9 kg per square meter, while obesity is defined as a BMI greater than 30. Steele and colleagues examined tumor incidence rates using data from the US Cancer Statistics 2014, as well as looking at trends between 2005 and 2014. More specifically, the researchers looked at the 13 types of cancer that have traditionally been associated with being overweight and among the obese. These include esophageal adenocarcinoma, postmenopausal breast cancer, colorectal cancer, endometrial cancer, gallbladder cancer and gastric carcinoma. In the second line, researchers have observed kidney, liver, thyroid, ovarian and pancreatic cancer. The report also examined the incidence of meningioma, which is a type of slow-moving brain tumor, and multiple myeloma.
Steele and his team have grouped and analyzed data by gender, age, ethnicity, geographic area, the site where the cancer appeared and the trends both with and without the incidence of colorectal cancer. As they explain, this is due to the fact that screening for this tumor can reduce the incidence, because the procedure often detects colo-rectal polyps before they become malignant. The final data were staggering: in 2014, about 630,000 people in the United States received a diagnosis of one of the tumors mentioned above, which represents an incredible 40% of all diagnosed cancers. The incidence rate was particularly high in adults over the age of 50. In fact, 2 out of 3 of these tumors have occurred in those aged between 50 and 74 years. At the sex level, more cancers have been linked to obesity in women than men. And more precisely, 55% of cancers affecting women and 24% of those affecting men have been linked to obesity.
Regarding obesity-associated tumors, these increased by 7% between 2005 and 2014. By comparison, the incidence of tumors not associated with obesity decreased by 13% during that period. Colorectal cancer also decreased by 23%, probably due to increasingly extensive screening practices. Dr. Brenda Fitzgerald, director of the CDC, comments on the results: “The burden of cancer with overweight and obesity is high in our country and could be reduced through prevention efforts to control overweight and obesity. The majority of American adults weigh more as recommended, and overweight or obesity puts people at higher risk for a number of cancers. So these results are a cause for concern; everyone can play a role in cancer prevention”.
- edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
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