More options now available for treating pancreatic cancers
Harvard Medical School Adviser by the Faculty of Harvard Medical School
I am a 55-year-old man who was recently diagnosed with pancreatic cancer. It is a neuroendocrine tumor. My doctor will be performing surgery in a couple of weeks and has discussed some new drugs that the FDA recently approved. Can you help me understand my diagnosis and the new drugs?
A cancer diagnosis can make a person feel very alone, but be assured you are not alone in your diagnosis. About 44,000 Americans will be diagnosed with pancreatic cancer this year -- accounting for approximately 3 percent of all cancer diagnoses.
Neuroendocrine tumors and the more common type of pancreatic cancer start from different types of cells. They have different symptoms and are treated differently. People can lead relatively normal lives for several years with a neuroendocrine tumor, even if the disease has spread outside the pancreas.
There are two new FDA-approved drugs for pancreatic neuroendocrine tumors. They are sunitinib (Sutent) and everolimus (Afinitor). These new drugs disrupt molecular-level signaling within cancerous cells. They work in a much more targeted way than conventional chemotherapy. Cancer specialists see these two new drugs and drugs like them as the exciting new wave of cancer therapy.
Your doctor may have reviewed this information with you, but it may help to briefly describe the pancreas. It is a gland that's situated at the back of the abdomen, where it's close to and connected with many other structures in your body. The pancreas has two main functions: It produces digestive fluids and enzymes that are released into the small intestine, and it produces insulin and other hormones that are released into the bloodstream.
It is thought that the common type of pancreatic cancer comes from cells that produce digestive juices, while the neuroendocrine tumors arise from islet cells responsible for insulin and other hormones. This is the traditional view, but new evidence is suggesting that both types of cancer may originate from stem cells.
Your doctor has probably explained that your type of cancer can be removed surgically. Generally speaking, though, the operation is not performed if the cancer has spread beyond the pancreas itself. In that case, a surgical procedure does little to alter the course of the disease.
Up to 30 percent of pancreatic neuroendocrine tumors result in excess release of insulin or other hormones. If too much insulin is pumped out, blood sugar levels can plummet. Extra gastrin, a hormone that stimulates the stomach, can lead to stomach ulcers. Surplus glucagon can make blood sugar levels go up.
Now medications called somatostatin analogs are used to control hormone release. They may also slow the growth of the tumors.
Conventional chemotherapy is used to treat pancreatic neuroendocrine cancer after it has spread. It extends lifespan, but it doesn't cure the cancer.
The two new drugs sunitinib (Sutent) and everolimus (Afinitor) are exciting alternatives to conventional chemotherapy. Sunitinib inhibits an enzyme critical to a complex chain of chemical events -- a "signaling pathway." By doing so, it inhibits the spread of cancer cells.
Everolimus inhibits a different enzyme, mTOR, and a different pathway. The basic concept of homing in on a molecular-level target specific to cancer cells is the same.
Research shows that sunitinib and everolimus can cut the growth of pancreatic neuroendocrine cancers in half. But these new medications do have side effects, including high blood pressure and low white blood cell counts. Overall, however, these side effects are less serious than those from conventional chemotherapy.
The bottom line is that in this new era of targeted drugs, unusual cancers are becoming more treatable. A diagnosis of cancer is never welcome, but your diagnosis comes at a hopeful time.
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