Obesity 'hikes' pancreatic risk
Obese women, who carry most of their excess weight around the stomach, are 70% more likely to develop pancreatic cancer, research suggests.
Obesity was thought to increase the risk - but more in men than women.
However, the new study, of more than 138,000 postmenopausal US women over seven years, suggests it is a significant risk factor for women too.
The study, by Sweden's Karolinska Institute, appears in the British Journal of Cancer.
In total 251 women in the study developed pancreatic cancer.
After taking account of other risk factors such as smoking, the researchers calculated that the disease was 70% more likely in women with the highest waist-to-hip ratios - a measure of obesity.
Lead researcher Dr Juhua Luo said: "We found that the risk of developing pancreatic cancer was significantly raised in obese postmenopausal women who carry most of their excess weight around the stomach."
Pancreatic cancer is the UK's sixth most common cause of cancer death.
In 2004, around 7,400 cases of pancreatic cancer were diagnosed in the UK, and there are around 7,000 deaths from the disease each year.
Usually, the disease is diagnosed only once it has spread and is difficult to treat successfully.
Only 2-3% of people survive beyond five years after being diagnosed.
The researchers believe obesity may increase the risk of pancreatic cancer by affecting insulin levels.
Dr Luo said: "We know that carrying a high proportion of abdominal fat is associated with increased levels of insulin, so we think this may cause the link between obesity and pancreatic cancer."
Dr Lesley Walker, of the charity Cancer Research UK, said: "Pancreatic cancer is associated with particularly poor survival, so it is crucial that we learn more about how to prevent the disease.
"About a quarter of all cancer deaths are caused by unhealthy diets and obesity and it's important that people are aware of this risk."
Pancreatic cancer develops from the cells within the pancreas, a gland located high up in the abdomen just behind the stomach.
If pancreatic cancer is not treated, cancer cells can spread into nearby organs or lymph nodes, or, eventually, break away and spread to other parts of the body.
Each year about 28,300 Americans and 3,100 Canadians are diagnosed with cancer of the pancreas, a small gland sandwiched between the stomach and intestine that secretes chemicals used in digestion. Epidemiologists estimate that smoking causes about 30 percent of all cases of pancreatic cancer. Men are 30 percent more likely to develop this type of cancer than women, and in the United States, pancreatic cancer affects African Americans more than any other ethnic group.
The pancreas is composed of two different types of glands: exocrine and endocrine glands. Exocrine glands, which make up the bulk of the pancreas, produce enzymes that help the body break down fats and proteins. About 5 percent of the cells in the pancreas are endocrine glands. These cells secrete the hormones insulin and glucagon, which help control blood sugar levels. About 95 percent of all cancers that originate in the pancreas are adenocarcinomas of the exocrine glands. Cancers of the endocrine glands are very rare, and the following discussion pertains to cancer of the exocrine glands.
Although rarer than many types of cancer, pancreatic cancer is the fourth leading cause of cancer death in the United States because it produces few if any symptoms before it metastasizes. When symptoms are present, they may include jaundice, a yellowing of the skin, eyes, and fingernails; abdominal pain; weight loss; and digestive problems. Usually by the time symptoms appear, the cancer has spread to distant organs in the body. For this reason, only about 4 percent of all people diagnosed with pancreatic cancer in the United States survive five years or more.
Epidemiologists estimate that smoking causes 30 percent of all cases of pancreatic cancer, the fourth leading cause of cancer death in the United States. The pancreas has both a digestive and a hormonal function. Composed mainly of exocrine tissue, it secretes enzymes into the small intestine, where they help break down fats, carbohydrates, and proteins. Pockets of endocrine cells called the islets of Langerhans produce glucagon and insulin, hormones that regulate blood-sugar levels. About 95 percent of all pancreatic cancers begin in the exocrine tissue.