Showing posts with label lantus. Show all posts
Showing posts with label lantus. Show all posts

Wednesday, December 7, 2011

More Evidence that Lantus Causes Cancer

There is a new study reported in Bloomberg this morning that Sanofi’s Lantus Doubled Cancer Risk in Study of Diabetics. The study, which was presented yesterday at the San Antonio Breast Cancer Symposium retrospecitvely evaluated medical records of 23,266 patients in southern Sweden and determined that diabetics who used Lantus had a 2.9-fold greater chance of cancer, while those who took the generic drug metformin had an 8 percent lower risk.

I have previously blogged about this back in 2009 when the first reports surfaced about the link between Lantus and cancer. (See A New Problem With Insulin: Cancer ,  Lantus Causes Cancer! Why Doesn't Anyone Seem Care? and Lantus and Cancer- A Closer Look Is Not Reassuring )

Back in 2009, when the story broke, the FDA acknowledged the potential link but stated that the data was insufficient and recommended that patients not stop taking Lantus, at least without discussing this with their physicians. They stated that they were "currently reviewing many sources of safety data for Lantus, including these newly published observational studies, data from all completed controlled clinical trials, and information about ongoing controlled clinical trials, to better understand the risk, if any, for cancer associated with use of Lantus." However, we didn't hear much until January, 2011 when they released an update declaring that they had reviewed the four 2009 studies and has "determined that the evidence presented in the studies is inconclusive", and in addition had reviewed results from a 5 year study (sponsored by the makers of Lantus) which did not show an increased risk but was  "not specifically designed to evaluate cancer outcomes," concluding, "at this time, FDA has not concluded that Lantus increases the risk of cancer. Our review is ongoing, including review of information from a current clinical trial." With the new study reported today, it will be interesting to see whether the FDA chooses to give and update or reveals and additional information, such as a VA data set they are supposed to be evaluating.

According to the Bloomberg article, a Sanofi study from Sweden, Norway, Finland, Denmark and Scotland is complete and will be submitted to health authorities this month.  In addition,  U.S. study will be finished in early 2012, while a final report from Europe will come later. All of these studies combined will involve more than a million patients, which will hopefully be enough to give a more conclusive answer.

To be clear, I am not 100% convinced that Lantus causes cancer.  However, there is another long acting insulin (Levemir) which has similar efficacy to Lantus, has not been associated with cancer, and has a substantially different affinity for the insulin like growth factor (IGF) receptors that are implicated in the possible connection.  Given the mounting evidence of a cancer link with an equally effective product that appears to be safer, I can't see any reason to prescribe Lantus when Levemir is available.

Thursday, July 2, 2009

Lantus and Cancer- A Closer Look Is Not Reassuring

Kevin MD brought up the issue of Lantus and cancer on his blog, linking to both my original post which stated that patients should be concerned, as well as a post from Amy Tenerich at Diabets Mine who takes a more conservative approach, like the ADA and AACE. ( I do question the motivations of these groups in my recent post on this matter: Lantus Causes Cancer! Why Doesn't Anyone Seem Care? ). Some responders to my inital post felt that I had not read the studies correctly. Therefore, below is my detailed interpretation of the four studies recently presented which caused the controversy.

The first study was a German study of 127,000 patients, which 20,000 were treated with Lantus. Most of these patients had Type 2 diabetes. Overall, this study found a correlation with all insulins and cancer, but no difference between the analogue insulins. However, because patients on combination analogue and human insulin were excluded in the study, the dose of lantus was much lower than the other analogues. The researchers then adjusted for insulin dose, and they found a dose dependent relationship of cancer and Lantus. The magnitude of this effect was such that 1 cancer might be caused for every 100 patients taking Lantus for a year. One of the limitations of the study was that it was not possible to break the analysis down by types of cancers caused. Given this and other possible limitations, the editors of the journal decided not to publish this study until these results could be replicated in other studies/countries, especially considering the importance of the findings if corroborated.


Since then 3 other studies were performed, and subsequently all four were published together.



The second study was a Swedish study matched a national cancer database and a national diabetes database looking for a connection. This study included over 120,000 patients of which about 6000 were on Lantus. They found no increase in risk for cancer with Lantus when taken with other kinds of insulin. These patients were younger, and more likely to have type 1 diabetes. However, analysis of patients who took Lantus alone, most of whom had type 2 diabetes, showed a doubling of breast cancer, which was highly statistically significant (though no increase in other types of cancers).


A third Scottish study used national database registeries similar to the Swedish study and they found exactly the same thing. The patients who took Lantus with other insulins, who were generally younger type 1 diabetics had no increased risk of cancer with Lantus compared to human insulin (actually had lower rates) but the patients on Lantus without other insulins, mostly older type 2 diabetics had a higher risk of cancer. There was also similarly an increased risk of breast cancer in women taking Lantus alone, which was about the same magnitude as the Swedish study.



The fourth study looked at cancer risks associated with a range of insulins. This retrospective UK study looked at over 62,000 adults that were started on oral agents and/or insulin. Diabetes developed in adulthood, so these were mostly type 2 diabetics. In general, the study found no difference between human insulin and analogue insulins like glargine (Lantus). However, the study did find that metformin use is associated with a lower risk of cancer, and seemed to abolish cancer risk. Also, only 10,000 patients in the study were on insulin, and only 2000 on Lantus. Plus, it was not clear who was taking meformin plus Lantus. Thus, given the very small number of patients on Lantus, some of who may have been taking metformin, this negative finding is not all that reassuring.

Taken together, in my opinion, these 4 studies strongly suggest a link between new cancers in adult type 2 diabetics who are taking Lantus alone. Now, we can't say that Lantus actually causes cancer. In fact, it is unlikely that Lantus actually causes cancer alone, because it takes years to develop most cancers. However, it is more likely that Lantus causes existing cells to grow and divide more rapidly. Usually, the body's own natural cancer fighting abilities take care of these cells. In other words, though Lantus may not cause cancer, adult type 2 diabetics taking Lantus seem to develop clinically apparent cancers at much higher rates (double for breast cancer) then those not on Lantus. Though whether or not Lantus is causative of cancer is an interesting academic discussion. However, from the patient's standpoint if taking Lantus increases the likelihood they will develop cancer, that's all they need to know.



Large observational studies are far from perfect. The can detect differences (i.e. adult type 2 diabetics taking Lantus were more likely to get cancer), but can detect the reasons for these differences. The only way to show actually causation would be a very large, randomized control trial conducted over years. However, this will take years to complete. The Europeans are suggesting meta-analysis of even larger databases to find out sooner.

Until we know for sure, given a possible risk for Lantus increasing the rate of cancer development, I would suggest it would be prudent to stop taking Lantus if you are a type 2 diabetic, especially if you are not taking other kinds of insulin. Detemir insulin (Levemir) is a reasonable alternative. Though it has not been studies as extensively, its effect on the IGF-1 receptor (the purported mechanism of the cancer association) if much, much less than Lantus.

Wednesday, July 1, 2009

Lantus Causes Cancer! Why Doesn't Anyone Seem Care?

The answer is probably money, but more on that later.

I recently posted on the Lantus/cancer connection in my post A New Problem With Insulin: Cancer. The concern was triggered in a press release about a recent European report based on one earlier and three new studies which show a link between Lantus, a long acting insulin, and cancer. As I mentioned, I though it was interesting that more alarm has not been raised, particularly here in the US. Nissen's poorly done Avandia study got major press, and people stopped taking the drug (He was recently proven wrong- see here fore more info). Yet, for Lantus, the report is not about one study, but four studies that show similar findings that Lantus increases rates of cancer. In addition there are some biologically plausible reasons (more later) and a clear dose response. If you look at the criteria for causation, the Lantus/cancer connection seems to ring true. Yet, there seems to be not that much in the press and little public outcry to pull the medication from the market. This may be in part to the fact that the news cycle is now 24/7 Michael Jackson, but other medical stories, like the FDA and Tylenol, seem to be getting some attention, so this can't be the entire reason.

What do the experts say? The Europeans are making "an urgent call for more research". Yet, the US response is much more subdued. The official response from the American Diabetes Association (ADA) stated that findings from these research papers are conflicting and inconclusive, and cautioned against over-reaction until more information is available. A similar response can be found from The American Association Of Clinical Endocrinologists (AACE), the smaller but more academic group of diabetes specialists.

Where is the media attention on this? Where is the warning to patients? Why doesn't anyone seem to care?
MJ aside, here are some reasons:

1. The US experts don't want to say too much because of their ties to the drug companies. Both the ADA and AACE receive huge amounts of money from corporate sponsors, specifically the drug companies. In fact, back in 5/07 the experts issued a joint statement that had similar comments on the Avandia scare (which turned out to be correct). Sanofi-Aventis, the maker of Lantus, gives money to both of the ADA and AACE, and their members are unlikely to bite the hand that feeds them.

2. Though not all endocrinologists think alike, based on national and international diabetes recommendations, the expert guidelines recommend the use of insulin in type 2 diabetes much sooner than I would recommend. I have blogged in the past that I believe the endocrinologist making these recommendations may have a conflict of interest in that they have an incentive to make recommendations that will lead more patients toward insulin is because insulin use in type 2 diabetics is how they make their living. It is possible that the endocrinology experts are cautious about scaring the public about Lantus, because this may cause concern about all insulins, which they believe is the best treatment for diabetes.

3. The reason why Avandia drew more attention is because Dr. Nissen and some Congressmen were the ones making the noise, not the specialty societies. The Nissen meta-analysis on Avandia, from the data analyzed, to the publication, to the media frenzy had political motivations, whereas the Lantus studies do not. (See a timeline of the politics of the Avandia study in my post Diabetes Conspiracy )

What now?
Thanks to a comment on my previous post, I looked into the matter a little more. One of the problems with insulin is that is that it is related to insulin like growth factor (IGF-1) which has been shown to stimulate tumor growth. Regular human insulin has some affinity for the IGF-1 receptor, but Lantus has a much greater affinity, which is the likely reason more cancers were seen. There happens to be another long acting insulin on the market called Levemir that has very little affinity for the IGF-1 receptor (less than even human insulin) and is as effective as Lantus. In 2008, Lantus just missed the top 25 most commonly prescribed branded drugs at #26 with over 10.25 million prescriptions that year. Levemir came in at #170 with only 1.3 million prescriptions. Though I doubt this is public knowledge, I would guess that Novo Nordisk (the company that makes Levemir) is not giving nearly as much to these organizations as Sanofi Aventis (makers of Lantus), but I could be wrong. Since Levemir is a newer drug, is was not included in these studies and one can not rule out potential harm. That said, its low affinity for IGF-1 is reassuring. Thus, upon further reflection, I think that all diabetic patients who are on Lantus should talk to their doctor about insulin use, and if they need it, ask their doctor to consider switching them to Levemir.


Update: Via Med Page today, FDA just announced they were going to look into this. Not sure how much press this will garner. Certainly more valuable use of their time then trying to take down Tylenol.

Monday, June 29, 2009

A New Problem With Insulin: Cancer.

Followers of this blog will note that my approach to the management of Type 2 diabetes is different then currently recommended guidelines. Unlike current recommendations which seem to push insulin after the failure of two older oral agents (which are known to fail), I recommend that multiple agents be used, reserving insulin as a last resort. I have blogged before about my concerns with insulin (The Problem With Insulin , The Problem with Insulin- Part 2 ). While life-saving for all type 1 diabetics and many type 2 diabetics, insulin causes many problems including the need to frequently monitor finger stick glucose, costs, inconvenience, weight gain, and hypoglycemia which can lead to death.

However, a new concern regarding glargine insulin (trade name Lantus) seems to be emerging. This press release best explains it. In summary, a recent study confirmed earlier findings between increased rates of cancer in diabetes taking glargine insulin and regular insulin, in particular, a doubling risk of breast cancer.

Why might this be true?
Human and even porcine insulin has a long track record of safety. However, glargine insulin is different in that it is not "natural" but a manufactured insulin, specifically modified to last longer. While insulin has been used for decades, glargine has only been used since 2000. Other reasons to consider this more than just a concern include that the findings are reproduced in multiple studies of tens of thousands of people, and that the finding seem dose dependent. In other words, the higher the dose of glargine one takes, the higher the risk of cancer. In order to know for sure, we need a randomized, controlled trial of thousands of patients to prove this is the case. This is exactly what the European Diabetes Association is calling for. However, those findings will not be available for years.

Why be concerned?
Most guidelines for type two diabetes recommend that long acting insulins be started first, and most clinicians usually start with the synthetic, glargine type of insulins. In fact, the preferred regimen for insulin in type 2 diabetics by most endocrinologists is a combination of a long acting insulin like glargine given once a day with very short acting insulins (lispro) at meal times. This approach, called basal-bolus, is supposed to mimic what the pancreas naturally does. Though I am glad that the European endocrinologists have raised concern and are calling for more data, I find it interesting that more alarm has not been raised, particularly here in the US. One very poorly done study which has now been proven to be false, caused so much uproar that people simply stopped taking Avandia. Yet, study after study shows a compelling and dose responsive relationship between glargine and cancer, and there seems to be little in the press.

What should you do?
If you are on Lantus, don't stop!!!! Please discuss this with your doctor first. There are other options other than Lantus, and even with an increased cancer risk, Lantus still may be the best option for you. If you are diabetic, but not yet on insulin, first do everything you can to avoid this. First and foremost, diet and exercise are key and critical. If that doesn't work, in addition to lifestyle changes, consider using multiple pills before resorting to insulin. If injections are needed, talk to your doctor about the incretin mimetics, like Byetta as alternatives to insulin. Studies of shown that in patients who failed diabetes pills, Byetta performed similarly to glargine in controlling diabetes but with less hypoglycemia and weight gain.