Pancreatic Cancer and Fat Hormone Linked
Pancreatic cancer is one of the most difficult forms of cancer to understand and to treat, and it is also one of the most deadly. Now investigators with a new study have discovered a link between a fat hormone called adiponectin and pancreatic cancer, and the information may be promising news.
What do we know about pancreatic cancer?
Besides being the fourth main cause of cancer death in the United States, much is still unknown about pancreatic cancer. Thus far experts have identified only a few risk factors for the disease, including smoking, diabetes, and a high body mass index (obesity), which can be associated with many other diseases as well.
A new discovery may offer clinicians important information, and that discovery concerns adiponectin, which is a hormone made and secreted exclusively by fat cells called adipocytes. Adiponectin helps regulate the breakdown of glucose and lipids and therefore has an impact on how the body responds to insulin.
According to the study's authors, their findings "provide additional evidence for a biological link between obesity, insulin resistance, and pancreatic cancer risk and also suggest an independent role of adiponectin." Another risk factor for pancreatic cancer is long-term pancreatitis, which is painful inflammation of the pancreas.
In the new study, which was conducted under the guidance of Ying Bao, MD, ScD, of Harvard Medical School, and colleagues, individuals with pancreatic cancer were found to have significantly lower levels of adiponectin in their blood, when compared with controls, at least one year before their diagnosis.
This low level of the hormone was independent of other risk factors for pancreatic cancer. However, there has been increasing evidence that obesity plays a significant role in pancreatic cancer, and so the discovery concerning this fat hormone is of special interest.
The study involved five cohorts that had more than 360,000 participants. Among this group, 468 individuals had pancreatic cancer, had no other forms of cancer, and had provided a blood sample more than 12 months before their diagnosis. These patients were matched with 1,080 controls.
Here's what the researchers found:
- The average adiponectin level was 6.2 micrograms per milliliter (mcg/ml) in people with pancreatic cancer and 6.8 mcg/ml in controls. This difference was significant.
- When the researchers divided the adiponectin levels into quintiles, higher levels of the hormone were associated with a lower risk of developing pancreatic cancer.
- Although the discovery has established a relationship between adiponectin and the risk of pancreatic cancer, more information is needed to determine the exact association between the hormone and the cancer. Authors Jianliang Zhang, PhD, and Steven Hochwald, who are both at Roswell Park Cancer Institute, noted that the new information concerning adiponectin "has the potential to improve the survival rates of pancreatic tumor patients."
Pancreatic cancer is difficult to detect in the early stages because it often doesn't cause symptoms. When symptoms do appear, they may include the following:
- Pale stools
- Dark urine
- Jaundice (yellow eyes and skin)
- Pain in the upper stomach region
- Pain in the middle of the back
- Nausea and vomiting
- Floating stools
- Advanced symptoms may include weakness, fatigue, loss of appetite, unexplained weight loss, and feelings of fullness
Treatment options for pancreatic cancer include chemotherapy, targeted therapy, radiation, and surgery, and most patients have a combination of therapies. Treatment can be successful if the disease is detected during the early stages (before it has spread) and surgery completely removes the tumor.
Pancreatic cancer remains a challenging form of cancer to detect and treat. The new discovery concerning a link between the fat hormone adiponectin and pancreatic cancer opens a door to new ways to prevent the development of the disease and improve survival among patients.
Bao Y et al. A prospective study of plasma adiponectin and pancreatic cancer risk in five US cohorts. Journal of the National Cancer Institute 2012; DOI:10.1093/incj/djs474
Zhang J, Hochwald SN. Plasma adiponectin: a possible link between fat metabolism and pancreatic cancer risk. Journal of the National Cancer Institute 2012; doi:10.1093/incj/djs522