European Association for the Study of Diabetes __________________________________________________________ Insulin analogues and cancer: a possible link that needs further investigation Diabetologia, the journal of the European Association for the Study of Diabetes (EASD), has
just published a series of research papers that have examined a possible link between one of
the insulin analogues and the risk of being diagnosed with cancer. This report provides a
There are more than 200 million people with diabetes worldwide. About 10% of these people
develop diabetes early in life, and most of them have what is known as type 1 diabetes.
People with type 1 diabetes have an absolute reliance upon insulin treatment for their
continued health and well-being. Type 2 diabetes, which affects the remaining 90%, typically
develops later in life and may be associated with excess weight. People with type 2 diabetes
are able to make some of their own insulin, which means that they can usually be treated
with diet and tablets in the early stages. At a later stage, however, many patients with type 2
diabetes lose the ability to produce their own insulin, and will then need insulin injections to
Human insulin has been very widely used for decades and its safety is established beyond
doubt. More recently, insulin manufacturers have developed modified insulins, known as
insulin analogues, which are intended to provide smoother or more precise control of blood
glucose levels. Some of these have been modified to give a very rapid onset of action, and
others have been designed to give a slow sustained release. The new information relates to
a long-acting analogue known as insulin glargine, or Lantus insulin. This is a popular insulin
that has been in widespread use since its introduction in 2000.
A study from Germany has raised some questions about Lantus—in particular whether it
might in some circumstances accelerate the development of cancer. In the light of these
preliminary findings, the EASD requested other diabetes research groups in Sweden,
Scotland and England to see if these findings could be reproduced in other independent
studies. All four papers are published online today and will subsequently appear in the print
EASD patient information sheet/Lantus/26 June 2009 European Association for the Study of Diabetes __________________________________________________________
What is the problem, and what is known about it so far?
Insulin glargine, also known as Lantus insulin, is a member of the new class of insulin
analogues used in the treatment of diabetes. It has a very similar structure to human insulin,
and lowers blood glucose in exactly the same way. Lantus passed the standard safety
checks required for all insulins before they go into clinical use, but was noted to promote the
growth of some cell types in the laboratory. This raised the theoretical possibility that it might
have the same effect on cancer cells growing in the body. It has not previously proved
possible to examine this possibility in large patient populations.
What did the researchers do in these particular studies?
The risk of all cancers, and of specific cancers commonly seen in type 2 diabetes, was
examined in the course of four separate studies based on large patient databases in
Germany, Sweden, Scotland and England. The rate of tumour diagnosis was compared in
patients with mainly type 2 diabetes taking Lantus as against other types of insulin. Between
them, these studies included details of about 300,000 patients, more than 10% of who were
on Lantus insulin. One of the studies also looked at cancer risk in tablet-treated patients.
Who was studied?
The study groups included 127,031 insulin-treated patients from a German insurance
database, 114,841 insulin-treated patients from Swedish Diabetes and Cancer registers,
49,197 patients from Scottish National Diabetes and Cancer registers, and 10,067 patients
from a UK GP database. This made a total of 301,136 insulin-treated patients, 34,392 of who
How were the studies done?
The German study compared the rate of all solid tumours in patients on Lantus alone versus
other insulins. Diagnosis of cancer was ascertained from the same database, as was the
dose of insulin prescribed for each patient. Individual cancer types were not examined.
EASD patient information sheet/Lantus/26 June 2009 European Association for the Study of Diabetes __________________________________________________________
The Swedish study focused on the rate of cancer development in patients treated with
Lantus insulin alone, as against any insulin other than Lantus, or Lantus taken in combination
with another insulin. Overall cancer risk was examined, and also the risk for cancer of the
breast, prostate or gastrointestinal tract.
The Scottish study was designed in the same way as the Swedish study. Patients were
divided into the same three categories of insulin treatment, i.e. Lantus insulin alone, as
against any insulin other than Lantus, or Lantus taken in combination with another insulin.
Overall cancer risk was examined, and also the risk for cancer of the breast, colon or
The UK study, based on a general practitioners’ (GP) registry, used a pre-existing dataset
that had examined cardiovascular risk in patients who were taking different forms of
treatment for their diabetes. This study included patients on tablets as well as insulin.
Patients on Lantus insulin alone were compared with patients on human NPH insulin alone,
and with patients treated with premixed human or analogue insulin preparations. The study
compared the rate of cancer for all cancers, and for cancers of the breast, colon, pancreas
Standard statistical adjustments were made in all the studies reported here for other factors
that might influence cancer risk, such as age and sex.
What did the researchers find?
The German study found no overall difference in cancer risk between patients treated with
Lantus and those treated with human insulin. Following statistical adjustment for insulin dose,
however, the analysis showed that a patient on Lantus was rather more likely to be
diagnosed with cancer than a patient on the same dose of human insulin. This difference
was roughly equivalent to one extra cancer diagnosed for every 100 people taking Lantus
The Swedish study found no increase in cancer risk, compared with human insulin, in
patients who took Lantus insulin together with other types of rapid-acting insulin. Those on
Lantus alone were, however, almost twice as likely to be diagnosed with breast cancer.
EASD patient information sheet/Lantus/26 June 2009European Association for the Study of Diabetes __________________________________________________________
There were no other differences in cancer risk between the groups. This difference would be
equivalent to about one new case of breast cancer for every 1000 women treated for 1 year.
The Scottish study found a slightly reduced cancer risk, compared with human insulin, in
those who took Lantus insulin with other insulins. As a group, however, these people were
younger and more likely to have type 1 than type 2 diabetes. In contrast, the group on Lantus
insulin alone, who were rather older than those in the two other groups, were more likely than
those on other insulins to have any form of cancer, breast cancer included, although the
difference for breast cancer did not reach statistical significance.
The UK study found no difference in risk of any cancer, including breast cancer, between the
four insulin regimens studied. Patients on metformin tablets were less likely to be diagnosed
with cancer than those people on other forms of treatment, and this was also seen when
metformin was taken in combination with other tablets, or with insulin.
What did the researchers conclude?
The researchers involved in these four studies all agree that these findings are not
conclusive. The need for caution arises mainly from the fact that these are observational
studies, and not clinical trials. A clinical trial ensures that patients on different treatments are
exactly alike in every respect apart from the treatment. An observational study examines
groups of people who may differ in many ways, such as age or type of diabetes, and then
makes statistical adjustments to allow for these differences. Even carefully performed
analyses, such as those reported here, cannot exclude the possibility that differences in
cancer risk may be due to differences between the groups of people included in the analysis,
rather than to differences between the treatments they are on. This means that further
studies are needed before we can reach a final conclusion. The EASD has already started
discussions with sanofi-aventis, the makers of insulin glargine, as to how these studies might
Insulin itself is a very safe form of treatment, and the researchers would emphasise that
there is no evidence whatsoever to suggest that treatment with this insulin analogue actually
causes cancer: at worst, it might promote growth of cancers that are already present but
EASD patient information sheet/Lantus/26 June 2009European Association for the Study of Diabetes __________________________________________________________
What are the implications of these results for patients currently using insulin analogues?
Lantus is a popular and widely used insulin. Many physicians and patients have found it
helpful on an individual basis, but systematic evidence from clinical trials has not shown it to
provide better overall glucose control than human insulin. There is little or no systematic
benefit in type 2 diabetes, although some patients with troublesome hypoglycaemia may find
The EASD does not recommend that you stop taking insulin glargine (Lantus) on the basis of
the evidence presented here, particularly if you have found it helpful in the management of
your own diabetes. People with diabetes do, however, have the option of using long-acting
human insulin or a mixture of long- and short-acting human insulin twice a day instead of the
once-daily analogue. You may wish to consider this option if you already have a cancer, or,
for women, if there is a family history of breast cancer.
You should not make any change in your insulin treatment without consulting your own
doctor, and you should on no account stop taking your insulin.
Disclaimer
This summary for patients is for information purposes only. It is a public service provided by the
European Association for the Study of Diabetes (EASD). This summary is not a substitute for advice
from your own medical provider. If you have questions about this subject, or need medical advice
about your own situation, please contact your doctor. This summary may be reproduced for non-profit
EASD patient information sheet/Lantus/26 June 2009
Common Illness & School Attendance Guidelines Fever: Any temperature greater than 100 degrees F is considered a fever. Children must be fever-free for 24 hours without using fever reducing medications (such as Tylenol, Motrin, Advil, etc.) in order to return to school. This applies even if the underlying cause of the fever is non-infectious, such as middle ear infections, bronchitis, urinary
Michael Anderson is a registered Psychologist in private practice in Torquay, Victoria. He has been practicing mindfulness meditation for over 25 years. In 1990 he became increasingly interested in Buddhism and mindfulness practice, and has from this time worked to integrate Western psychology and mindfulness approaches. He has training in ACT, Without a personal practice