What`s new in pancreatic cancer research and treatment?
Research into the causes, diagnosis, and treatment of pancreatic cancer is under way in many medical centers throughout the world.
Genetics and early detection
Scientists are learning more about some of the changes in DNA that cause cells in the pancreas to become cancerous. Inherited changes in genes such as BRCA2, p16, and the genes responsible for hereditary non-polyposis colorectal cancer (HNPCC) can increase a person's risk of developing pancreatic cancer. Researchers are now looking at how these and other genes may be altered in cases of pancreatic cancer that do not seem to be inherited. They have discovered that pancreatic cancer does not form suddenly. It develops over many years in a series of steps known as pancreatic intraepithelial neoplasia or PanIN. In the early steps, such as PanIN 1, there are changes in a small number of genes, and the duct cells of the pancreas do not look very abnormal. In later steps such as PanIN 2 and PanIN 3, there are abnormalities in several genes and the duct cells look more abnormal.
Researchers are using this information to develop tests for detecting acquired (not inherited) genetic changes in pancreatic cancer pre-cancerous conditions. One of the most common DNA changes in these conditions affects the KRAS oncogene and alters regulation of cell growth. New diagnostic tests are often able to recognize this change in samples of pancreatic juice collected during an ERCP (endoscopic retrograde cholangiopancreatography).
For now, imaging tests like endoscopic ultrasound (EUS), ERCP, and genetic tests for changes in certain genes (such as KRAS) are options for people with a strong family history of pancreatic cancer. But these tests are not recommended for widespread testing of people at average risk who do not have any symptoms.
The major focus of much research is on finding better treatments for pancreatic cancer. Improving surgery and radiation therapy are major goals, as is determining the best combination of treatments for people with certain stages of cancer.
Many clinical trials are testing new combinations of chemotherapy drugs for exocrine pancreatic cancer. Studies have looked to see if combining gemcitabine with other drugs would help patients live longer. Adding cisplatin, docetaxel, or irinotecan doesn't seem to be helpful, but adding capecitabine (Xeloda) or nab-paclitaxel (Abraxane®) does seem to help patients live longer. Also, the combination of gemcitabine, irinotecan, and celecoxib (an arthritis drug) shows promise. Other studies are testing the best ways to combine chemotherapy with radiation therapy or newer targeted therapies.
As researchers have learned more about what makes pancreatic cancer cells different from normal cells, they have started to develop newer drugs that should be able exploit these differences by attacking only specific targets. These "targeted therapies" may provide another option for treating pancreatic cancer. They may prove to be useful along with, or instead of, current treatment regimens. In general, they seem to have fewer side effects than traditional chemotherapy drugs. Looking for new targets to attack on cancers is an active area of research.
Growth factor inhibitors: Many types of cancer cells, including pancreatic cancer cells, have certain molecules on their surface that help them to grow. These molecules are called growth factor receptors. One example is epidermal growth factor receptor (EGFR). Several drugs that target EGFR are now being studied. One, known as erlotinib (Tarceva), is already approved for use along with gemcitabine.
Anti-angiogenesis factors: All cancers depend on new blood vessels to nourish their growth. To block the growth of these vessels and thereby starve the tumor, scientists have developed anti-angiogenesis drugs. These are being studied in clinical trials and may be used in patients with pancreatic cancer.
Other targeted therapies: Many drugs targeting other aspects of cancer cells are now being studied for use in pancreatic cancer. For example, drugs that target the action of farnesyl transferase, an enzyme that is thought to stimulate the growth of many cancers, are now being tested. Other drugs, such as sunitinib, have several different targets.
Immune therapies attempt to boost a person's immune system or give them ready-made components of an immune system to attack cancer cells. Some studies of these treatments have shown promising results.
One form of immune therapy injects man-made monoclonal antibodies into patients. These immune system proteins are made to home in on a specific molecule, such as carcinoembryonic antigen (CEA), which is sometimes found on the surface of pancreatic cancer cells. Toxins or radioactive atoms can be attached to these antibodies, which bring them directly to the tumor cells. The hope is that they will affect cancer cells while leaving normal cells alone. For use in pancreatic cancer, these types of treatments are available only in clinical trials at this time.
Some current studies are looking at different ways to give radiation to treat exocrine pancreas cancer. One study is looking at the effect of intraoperative radiation therapy, in which a single large dose of radiation is given to the pancreas at the time of surgery (in the operating room). Another study is looking at using a special type of radiation called proton beam radiation with chemo.
Individualization of therapy
Some drugs seem to work better if certain types of mutations can be found in the patient's tumor. For example, erlotinib may work better in patients if their tumors have a particular change in the gene for EGFR. This concept is an area of intense study. There might also be some genetic alterations that affect how well gemcitabine will work in a particular patient. Identifying markers that may predict how well a drug will work before it is given is an important area of research in many types of cancer.
New treatments for pancreatic neuroendocrine cancers
Many pancreatic neuroendocrine tumors have receptors for somatastatin on their cells. These tumors can be treated with octreotide and other drugs like it. A new drug has been developed in which the octreotide has been labeled with radiation. This drug shrunk some tumors and kept others from growing in an early trial. It also helped patients live longer.
Last Medical Review: 01/28/2013
Last Revised: 01/28/2013