Experts at the American Diabetes Association and the American Cancer Society are of the opinion that risk factors for diabetes as well as its treatment could have a connection with incidence of cancer.
The new report explores the state of science concerning the association between diabetes and cancer incidence/prognosis; risk factors common to both diseases; possible biologic links between diabetes and cancer risk; and whether diabetes treatments influence the risk of cancer or cancer prognosis.
In addition, the report outlines key unanswered questions for future research.
Diabetes and cancer are common diseases that have a tremendous impact on health worldwide.
Epidemiologic evidence suggests that people with diabetes are at a significantly higher risk of many forms of cancer.
Type 2 diabetes and cancer share many risk factors, but potential biologic links between the two diseases are not completely understood.
Moreover, evidence from observational studies suggests that some medications used to treat hyperglycemia are associated with either an increased or reduced risk of cancer.
Thus, the American Diabetes Association and the American Cancer Society convened a consensus development conference in December 2009.
After a series of scientific presentations by experts in the field, the writing group independently developed a consensus report to find if there is a meaningful association between diabetes and cancer incidence or prognosis.
And the researchers found that diabetes (primarily type 2) is associated with an increased risk of some cancers (liver, pancreas, endometrium, colon/rectum, breast, and bladder).
Diabetes is associated with a reduced risk of prostate cancer. For some other cancer sites, there appears to be no association or the evidence is inconclusive.
The association between diabetes and some cancers may be due in part to shared risk factors between the two diseases such as aging, obesity, diet, and physical inactivity.
Possible mechanisms for a direct link between diabetes and cancer include hyperinsulinemia, hyperglycemia, and inflammation.
Healthy diet, physical activity, and weight management reduce the risk and improve outcomes of type 2 diabetes and some forms of cancer and should be promoted for all.
Patients with diabetes should be strongly encouraged by their health care professionals to undergo appropriate cancer screenings as recommended for all people of their age and sex.
Cancer risk should not be a major factor when choosing between available diabetes therapies for the average patient.
For selected patients with a very high risk of cancer occurrence (or for recurrence of specific cancer types), these issues may require more careful consideration.