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.

13 comments:

Anonymous said...

Thank you for the update and agree there is no reason to use Lantus when the safer Levemir is available.

Anonymous said...

There is when Levemir doesn't work for you. I guess you have to be a Type 1 to know that.

Anonymous said...

A recent meta analysis was presented at the IDF meeting showing no association of cancer at all in about 50K patients over a million patient years. This last study was very, very small in comparison.

It looks to me that if an association exists, at all, it is extraordinarily small.

Anonymous said...

You cant compare an insulin to metformin and draw any conclusions from it, except that insulin or the people that need to take it have a higher risk of cancer perhaps. In order to determine if one insulin is more at risk over another, you have to compare them all. NPH, Lantus and Levemir. From what I understand, Lantus has a big study comparing against NPH and cancer rates are not significantly different. Levemir is vastly understudied compared to Lantus and efficacy is worse than Lantus.

Anonymous said...

Actually Levemir has 30+ documented studies so I disagree with the statement that it is understudied. Most docs have moved away from using NPH so the fact that the cancer rates of Lantus are similar to NPH is really insignificant. Levemir has over 7 years of data, in addition to the clinical trials conducted prior to it's entry into the market. There are studies that show a greater A1C reduction as compared to Lantus. Of course there are also studies which show less or similar A1C reduction as well. The same can be said for Lantus. But to make a broad statement that the efficacy of Levemir is worse than Lantus is outright false. Every patient is different & neither Levemir nor Lantus work for EVERY patient- that's just common sense. It's nice to have options, especially one such as Levemir, which has never shown an increased risk for cancer, coupled with a low affinity for the IGF-1 receptor.

Anonymous said...

So why not just bring back Ultra Lente? There is no perfect insulin out there, but I have read that human insulin is generally safer than synthetic insulins.

Dr. Matthew Mintz said...

Ultralente is a reasonable alternative. I would favor Levemir, since it has a very similar and favorable profile like Lantus, but does not appear to be associated with the cancer concerns.

Anonymous said...

Ultralente worked well for me and for my son; we're both Type I. We both now take Lantus, which works fine, but we have a family history of breast cancer, and I'm considering a switch to Levemir.

Anonymous said...

Have you read the data presented at the ADA this month Dr Mintz?
Check out Heartwire.org and Cardiobrief for the latest. Evidence is strong Lantus has no more risk of causing cancer than any other insulin.

Philadelphia, PA - New data presented this week appear to put to rest concerns about cancer in patients treated with insulin glargine (Lantus, Sanofi). Investigators reported data from three large databases, and in all three analyses there was no cancer signal observed in patients treated with long-acting insulin glargine.

"I don't think we've provided a definitive answer, but we've provided a much stronger answer that there seems to be no link," Dr John Buse (University of North Carolina, Chapel Hill), one of the researchers involved in the studies, told heartwire. "At the end of the day, I'm fairly satisfied with the safety of insulin glargine with regard to cancer."

Dr Peter Boyle (International Prevention Research Institute, Lyon, France), who conducted an updated meta-analysis of studies comparing the risks of insulin glargine with the risks of nonglargine insulin, including analyses of new users only, also found no evidence of breast, prostate, and colorectal cancer in the insulin-glargine-treated patients [1]. "We have over three million person-years of observation, and we failed to detect any increased risk," Boyle told heartwire. "I think that's pretty powerful evidence that if there's anything going on, it's trivial, but it's more than likely that there's nothing going on in terms of safety."

In addition to the three studies presented today here at the American Diabetes Association (ADA) 2012 Scientific Sessions, data from the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial, a six-year study of patients treated with insulin glargine, also revealed no signs of cancer in the active treatment arm.

Dr. Matthew Mintz said...

This post was published a year and a half ago when data was mounting that seemed to indicate a connection between Lantus and cancer. I am pleased to see from the more recent studies presented at the ADA a few weeks ago that the connection does not seem to hold true. That said, I would still remain cautious. My preference is to prescribe Levemir because they work about the same, and the reason why some believe that Lantus may increase cancer risk (affinity for a specific receptor) is not true for Levemir. That being said, for patients who seem to do better on Lantus then Levemir, it is probably OK to use Lantus.

Anonymous said...

I was on Lantus about 1 year and then was diagnosed with stage 2 , grade 3 triple negative breast cancer. Shortly after treatment I came across Dr. Mintz's article and had my endocrinologist switch me to Levemir. It works great for me. Triple negative breast cancer tends to be high in the insulin growth factor.Right now I am a 3 1/2 year cancer survivor. I don't know if this switch in insulin has anything to do with it but I don't think it is harming me either. When I read how much more insulin growth factor is in Lantus I just thought that is was a no-brainer to take a chance with Levemir.So far so good. Thank you doctor for not being afraid to point out this fact.
Janet C.

John Antony said...

I am a Lantus user and had a colon cancer recently. I have stopped using Lantus. The Novolog alone conrols my blood sugar and I dont understand why I should use Lantus with so much risk.

Dr. Matthew Mintz said...

John,
Since writing this article over a year ago, more data has come out in favor of Lantus. That said, I am not entirely convinced. The Novo product Levemir works just as well for many patients and is clearly not associated with this risk. If your sugars are controlled on the Novo product, that's fantastic. No need to take Lantus if your sugars are controlled