Do Diabetes Drugs Cause Cancer?

It all started with Actos (pioglitazone). When the very popular diabetes drug Avandia (rosiglitazone) was found to produce serious cardiovascular risks (increased likelihood of heart attacks and strokes), a competing drug called Actos took over. Full page ads in newspapers touted the benefits of Actos for controlling type 2 diabetes. Sales soared.
Then reports linking Actos to bladder cancer began to surface. In 2010 the FDA announced that it had begun a safety review of Actos after reviewing some worrisome results of a long-term study suggesting a possible link to bladder cancer.
In June of 2011 the FDA went a bit further: ”
“Actos: Potential Increased Risk of Bladder Cancer
The use of the diabetes medication Actos (pioglitazone) for more than one year may be associated with an increased risk of bladder cancer.”
The FDA offered the following recommendations:
Recommendations
• Do not take pioglitazone if you are being treated for bladder cancer.
• Tell your doctor right away if you have any of the following symptoms of bladder cancer:
• blood or red color in urine
• urgent need to urinate or pain while urinating pain in back or lower abdomen
As of this writing the FDA has done nothing more than issue a warning. But on August 9, 2012 the Journal of the National Cancer Institute released a report suggesting that there was indeed a worrisome link to bladder cancer. Investigators reviewed records from more than 60,000 people with type 2 diabetes in the United Kingdom. Those who took Actos were two to three times more likely to be diagnosed with bladder cancer compared to those taking other antidiabetes drugs. Although Actos remains available in the U.S., France and Germany banned the drug in 2011.
New Concerns: Byetta, Bydureon, Januvia, etc.
A report from Johns Hopkins University on February 25, 2013 in the journal JAMA Internal Medicine noted that GLP-1 drugs were linked to inflammation of the pancreas (pancreatitis). Symptoms include digestive distress, abdominal pain, nausea and vomiting.
A few weeks later on March 14th, the FDA issued a “Drug Safety Communication” about this entire class of medications:
“The U.S. Food and Drug Administration (FDA) is evaluating unpublished new findings by a group of academic researchers that suggest an increased risk of pancreatitis, or inflammation of the pancreas, and pre-cancerous cellular changes called pancreatic duct metaplasia in patients with type 2 diabetes treated with a class of drugs called incretin mimetics.”
“FDA has not reached any new conclusions about safety risks with incretin mimetic drugs. This early communication is intended only to inform the public and health care professionals that the Agency intends to obtain and evaluate this new information. FDA will communicate its final conclusions and recommendations when its review is complete or when the Agency has additional information to report. ”
“At this time, patients should continue to take their medicine as directed until they talk to their health care professional, and health care professionals should continue to follow the prescribing recommendations in the drug labels.”
According to the FDA, Drugs in this class include:
• Bydureon
• Byetta
• Janumet
• Janumet XR
• Januvia
• Jentadueto
• Juvisync
• Kazano
• Kombiglyze XR
• Nesina
• Onglyza
• Oseni
• Tradjenta
• Victoza
What is a patient to make of all this? The FDA generally moves quite slowly when it comes to cancer cautions. In this case, however, FDA staffers moved with surprising speed to alert the public and health care professionals to their concerns about possible precancerous changes within pancreatic cells. Nevertheless, the FDA has made it clear that patients should not stop taking their medicine.
This leaves millions of people in a double bind. It also puts doctors in a difficult position while the FDA investigates these new findings. It could take months, if not years, to sort through the data and determine whether there really is an increased risk of pancreatic cancer.
In the meantime, we encourage people to become as informed as possible about ALL options involving blood sugar control. In our new Guide to Managing Diabetes we discuss many non-drug options. You will learn about the Low-Cal vs. Low-Carb controversy and get practical recommendations on the best vegetables to keep blood sugar under control. Find out about the role of cinnamon, vinegar and supplements such as vitamin D, selenium and chromium as well as herbs like bitter melon, fenugreek and nopal cactus.
You will also learn about the pros and cons of metformin. Not only does this drug help control blood sugar without the usual weight gain associated with many other medications, it has been linked to a lower risk of cancer!
In June, 2012 a study published in the Journal of Clinical Oncology has some very good news about metformin:
“In a large population of postmenopausal women, use of oral metformin was associated with lower incidence of invasive breast cancer…Our results inform future studies evaluating use of metformin in the management and prevention of breast cancer.”
This isn’t the first time metformin has been linked to a lower risk of cancer. A comprehensive review of the medical literature published in Cancer Prevention Research (Nov. 2010) revealed that metformin was associated with a 31% reduced risk of cancer in general compared to other diabetes treatments. In particular, the reduction in rates of pancreatic and liver cancer were statistically significant.
To learn more about metformin’s benefits and risk as well as other practical ways to manage diabetes and prediabetes, we hope you will find our new Guide to Managing Diabetes worthwhile. Even if you have not been diagnosed with elevated blood sugar, we think the dietary suggestions in this guide will make sense for you and those your love.
Please let us know how you mange your blood sugar by commenting below.