Recent research from the Mayo Clinic and the University of Oslo may lead to new treatment options for tumors in the pancreas, one of the most deadly forms of cancer. The researchers identified a gene that influences the shape of pancreatic cells; targeting this gene could halt the development of tumors.
Picture a 6-inch pear lying on its side behind the lower part of the stomach – that’s the pancreas. It secretes enzymes that help in the digestion of food as it passes through the gut. The pancreas also contains endocrine cells that help regulate the metabolism of sugars – these cells produce insulin, which lowers the glucose concentration in the bloodstream; they also produce glucagon, which raises the concentration.
Pancreatic cancer is diagnosed in about 1.5 percent of the U.S. population – about 1 in 67 people. Its tumors are very difficult to treat, and while survival rates are improving, the disease is still considered to be largely incurable. The American Cancer Society reports that for all stages of pancreatic cancer combined, the 1-year survival rate is 20 percent, with a 5-year survival rate of only 6 percent. Frederick Weeks, M.D., is an internist and oncology specialist in Vero Beach; he says, “Treatments usually add six to eighteen months to a person’s life, although some patients do live longer.”
The Mayo Clinic and University of Oslo study was published in the online scientific journal Nature Communications. The gene in question is called protein kinase D1 (PKD1). The study’s co-lead investigator, Dr. Peter Storz, says, “As soon as pancreatic cancer develops, it begins to spread, and PKD1 is key to both processes. Given this finding, we are busy developing a PKD1 inhibitor that we can test further.”
Pancreatic cancer can develop when the enzyme-secreting cells in the pancreas (called acinar cells) morph into duct-like structures. Dr. Weeks says that there is usually no reason why this morphing occurs, although it could be related to repeated instances of pancreatitis, which causes inflammation.
Increasingly, researchers are using 3-dimensional (3D) cell cultures for their research. Think of a 2D culture as being in a flat dish, and a 3D culture being in a scaffold-like structure. In this study, the researchers used pancreatic cells from a mouse to develop a 3D model, enabling them to test the influence of the PKD1 gene. In basic terms, when the researchers blocked PKD1, they saw that fewer duct-like cells and lesions formed.
One of the problems with pancreatic cancer is that it is rarely detected early; symptoms often don’t appear until the disease has reached an advanced stage. According to the Mayo Clinic, when symptoms appear they can include:
• Upper abdominal pain that may radiate to the back
• Yellowing of skin and the whites of eyes
• Loss of appetite
• Weight loss
• Depression
• Blood clots
Many of these symptoms are either vague, or could be associated with other conditions, so it’s good to know the risk factors for pancreatic cancer; not all have to be present to increase the risk:
• As mentioned before, chronic inflammation of the pancreas (pancreatitis)
• Diabetes
• Family history of genetic syndromes that can increase cancer risk
• African-American race
• Family history of pancreatic cancer
• Smoking
If pancreatic cancer is suspected, there are a number of tests to rule out or confirm the diagnosis; these include imaging tests (ultrasound, CT scan, and MRI), scopes that create images of the pancreas from inside the abdomen, and biopsy – in which a tissue sample is removed for testing. “Biopsy is the gold standard in testing and with newer technology, like endoscopies, it’s viable in more and more situations,” Dr. Weeks says.
After pancreatic cancer is diagnosed and staged (determination made if the cancer is confined to the pancreas or has spread) the patient should discuss treatment options with their oncologist. The best-case scenario is for the cancer to be eliminated; if that’s not possible, treatment is focused on preventing any further growth.
“By the time symptoms appear, it’s usually too late for surgery,” Dr. Weeks says. The exception is if the cancer is confined to the head of the pancreas. If that’s where the cancer is, symptoms like jaundice, pancreatic, and back pain may appear, which can lead to a diagnosis and an operation called a Whipple procedure, in which the head of the pancreas, the gallbladder, a portion of the small intestine, and part of the bile duct are removed.
Radiation and chemotherapy, alone or in combination, are used before or after surgery, or if surgery is not an option. These of course come with various side effects, depending on the specific treatment, the stage of the cancer, and any other health conditions the patient may have.
There is an FDA-approved “targeted therapy” drug, called Tarceva, for advanced-stage pancreatic cancer. The manufacturers of Tarceva say it may slow or block the activity of a specific protein that cancer cells need to grow and divide. It is used in treating patients who have not received previous chemotherapy and whose cancer has spread, grown, or cannot be surgically removed. In Dr. Weeks’ opinion, it’s not a home run; he says he hasn’t been very impressed by the results he has seen so far.
Targeted therapies are of great interest to researchers and to the medical community at large, because they act on specific molecular targets associated with cancer; in contrast, chemotherapy has an effect on normal cells as well as those that are cancerous. The study from the Mayo Clinic and University of Oslo is promising, as it may lead to the development of additional targeted therapies for the treatment of this deadly disease.
Dr.Weeks’ office is located at 1460 36th St in Vero Beach; his office phone is 772-562-7777.
