Day 6 - Eighth Camp Blog Entry
July 23rd, 2009 by SteveAnalog insulins and Cancer?
There was a recent scare that associated the use of Lantus insulin (insulin glargine) with an increased rate of cancer. This report was based on a German health insurance database. The journal that reported it also was careful to include comparable studies from other countries where Lantus is used. The results from these other nations were less compelling. In fact one study showed no significant association between Lantus and higher rates of cancer. None of these studies looked at Levemir (insulin detemir), the other long acting basal insulin. The makers of Levemir are quick to point out that the chemical structure of Levemir is different from Lantus. This is relevant because insulin analogs (which is what both Lantus and Levemir are), also may cross react with receptors for growth factors on the surface of certain cells. The term for the cell growth promoting effect of any insulin molecule is its mitogenic effect. This is different from the blood sugar lowering effect of insulin.
It’s believed that human insulin itself does not cause cancer. However, it might be possible for an analog of insulin (like the two insulins being discussed) could drive the growth of abnormal cells that may have arisen by a separate process. For a body cell to become cancerous, it is thought that at least 6 different things (i.e., cellular “checks and balances”) must be breached in order for that cell to grow out of control (a primary trait of any cancer). It might be possible that some analog insulins could play a role in driving the rapid growth of existing abnormal cells. But the analog itself probably had nothing to do with the formation of the cancer in the first place. It may surprise some of you to know that cancerous and precancerous cells exist in many healthy people. These abnormal tissues may remain in check somehow until an outside force or substance drives the tissue to grow out of control. No one can say with any certainty that any analog insulin (including Lantus) doesn’t cause existing or hidden cancer cells to grow.
So, the bottom line is: keep using Lantus. There is no credible evidence any insulin (human or analog) causes cancer. But, without question Lantus and Levemir should both be carefully studied for any effects that might not have been apparent in the first few years of use, and not only cancer.
Don’t forget to check back later for tonight’s Diabetes Challenge Question!
Last 5 posts by Steve
- Halloween and Diabetes CAN mix! - October 5th, 2009
- Introducing Healthy Families of South Texas - October 5th, 2009
- Complications 101 - About Kidney Failure - August 23rd, 2009
- The Sleep Bolus - August 18th, 2009
- The Dirty Truth Behind DCCT - August 16th, 2009
July 24th, 2009 at 7:40 am
I disagree with the recommendation that patients who are concerned “should keep using Lantus because here is no credible evidence any insulin (human or analog) causes cancer.” The reality is there ARE insulin varieties that have decades of clinical usage that have been proven unequivocally NOT to cause cancer (for example, NPH has been used since 1950; by comparison, there are NO long-term studies of the safety of Lantus); therefore, if a patient is concerned, it is their prerogative to request to be switched to one of those insulin varieties, but they should also be advised that these insulin varieties may also have drawbacks (for their individual situation) and the patients should be able to then make an INFORMED decision.
(This comment has been moderated with the addition of comments by the editor below)
Editor’s comment: This post was written by a physician with a significant amount of training on the subject matter. The background information found within the post is not easily obtained elsewhere and the author was clearly working overtime (how many practicing pediatric endocrinologists are frequent bloggers?) to inform his patients as well as providing his qualified recommendation as a counter to a study recently hyped by the media and by competitors to the makers of Lantus. So, I’m not sure I understand the rationale for this comment but agreed to share it in the spirit of respecting others opinions and encouraging healthy and respectful dialogue. Kevin McMahon, Editor - Challenge Diabetes Blog