Ian Blumer, MD, Diabetes Specialist in Toronto, Canada and author of Diabetes for Dummies

“Just when those of us in the diabetes community have been riding a wave of reassurance from very recent studies showing favorable rosiglitazone safety results, comes word of studies published in the current issue of Diabetalogia raising the question as to whether insulin glargine (Lantus) may be associated with an increased risk of cancer. The phones are already ringing off the hook as concerned glargine-using patients call to find out what they are to do….”

 This is what he has been telling his patients:

 “Indeed, new studies have just been published suggesting there may be an increased risk of cancer if you are taking Lantus insulin. At this time, however, I do not feel we have nearly enough proof of this to warrant you changing your insulin and you should definitely not discontinue using insulin. The studies that were done did not involve starting a group of patients on Lantus then monitoring their progress; rather, it looked backward at groups of Lantus-using patients to see what happened to them with the passage of time. These types of studies are typically not nearly as accurate and are prone to flaws. It could turn out, therefore, that the recent studies’ conclusions were simply incorrect; at this time we simply don’t know. Of course, if you remain concerned, we could change you to another very long-acting insulin but the only other one available — Levemir  — wasn’t included in these recent studies so we don’t know if similar observations would or wouldn’t have been made. That leaves us with one other option –– changing you to NPH insulin — but its properties are very different from Lantus and Levemir — and it may not be as suitable a choice for you. At this time, unless you request otherwise, I would recommend we continue with your current insulin and I’ll keep a close eye on the medical literature to see what evolves on this subject over the next while. Just so you know, the American Diabetes Association and the European Association for the Study of Diabetes (which actually published the articles we’re talking about) agree with this ‘wait and see’ strategy.”