There are several evidences till now and many evidences are in the process of getting exposed that the type 2 diabetes individuals are at higher risk of malignancies like breast, colon, liver, pancreas and endometrium1. The epidemiologic evidences have shown that individuals suffering from type 2 diabetes are at higher risk of many forms of cancers. Some of the risk factors associated with diabetes are found to be common for cancer as well. The biological association of diabetes with cancer is not completely studied till now. Some of the observational studies indicate confirmedly that certain drugs used for treating hyperglycemia were found related to higher or lower risk for cancer.
Taking this concept into the subject of concern, there was a conference held in December, 2009 which was organized by the ‘American Cancer Society’ and the ‘American Diabetes Association’. Following certain collection of presentations given by some experts, some of the writers have come forward to generate a consensus report to provide answers to some significant questions like:
- What are the common risk factors of cancer and diabetes?
- Will the diabetes medications have impact on risk for cancer or on cancer prognosis?
- Is there actually any association between diabetes and cancer prognosis or incidence?
- What are the scientific evidences for the relationship between cancer risk and diabetes?
In more than fifty years of time, there were situations where the patients had diabetes and cancer concurrently. The types of cancers that are mostly observed in diabetes patients were breast, lung, colorectal and bronchial cancers2. In a publication by Joslin etal.3 in 1959 it is indicated that many studies were done on the association of diabetes and cancer since many years. But, this association was not observed confirmedly positive. In population dependent studies done in 1960s it is identified that diabetes and cancer are associated. All the results of these studies were collected and analyzed later to conclude that some cancers developed in people with type 2diabetes very frequently. The association was mostly seen positive in the case of type 2 diabetes than in type 1 diabetes cases. The men with diabetes were less likely to report with prostate cancer.
The liver, endometrium and pancreatic cancers are relatively at two fold higher risk of incidence by diabetes while bladder, colon, rectal and breast cancers are at little lesser risk (about 1.5 fold) due to diabetes. Lung cancer risk seems to be not associated with diabetes while the other studies on non-Hodgkin lymphoma did not provide any conclusive results. Some of the studies have shown the association of cancer risks with type 1 diabetes as well. The association between enhanced risk for most common cancers and diabetes was identified but, the association of cancer prognosis and the less commonly occurring cancers with diabetes was not established yet. Whether the association is direct or indirect is also not concluded.
Source: Edward Giovannucci, David M. Harlan, Michael C. Archer, Richard M. Bergenstal, Susan M. Gapstur, laurel A. Habel, Michael Pollak, Judith G. Regensteiner, and Douglas Yee. Diabetes and Cancer- A consensus Report. Diabetes Care, July 2010; 33(7): 1674-1685. http://care.diabetesjournals.org/content/33/7/1674.long
Joslin EP, Lombard HL, Burrows RE, and Manning MD. Diabetes and Cancer. N Engl J Med, 1959; 260: 486 – 488.