In a retrospective examination, researchers have determined that specific types of childhood cancer treatments result in elevated risks for developing diabetes later in life.
Six American research hospitals, along with the University of Alberta in Canada, collaborated on the study, which looked at more than 8,500 cancer cases in which a cancer patient age 21 or younger was treated for leukemia, bone tumors, central nervous tumors, Hodgkin lymphoma, non-Hodgkin lymphoma, renal tumors, soft-tissue sarcomas or neuroblastoma.
Through a survey, each patient was asked whether or not they had taken diabetes medication for longer than a month in the past two years. The same survey was given to the siblings of each cancer survivor.
In total, 2.5 percent of all survivors surveyed reported that they had taken diabetes medication. Only 1.7 percent of healthy siblings reported doing so. Following adjustments for age, gender, race, body mass index and other factors, researchers determined that childhood cancer survivors are 1.8 times more likely to develop diabetes.
More over, cancer patients will develop diabetes at a younger age. Figures show that 57 percent of cancer survivors with diabetes were under the age of 35, as opposed to only 35 percent of the siblings.
Diabetes risk varied depending on the specific type of cancer treatment performed. Patients undergoing total body irradiation were at the highest risk (12.6 times more likely than siblings). Patients receiving abdominal irradiation were three times more likely to develop diabetes. In total, patients treated for total body, abdominal or cranial irradiation were found to be 90 percent more likely to experience diabetes later in life.
Additionally, it was found that patients who were treated for cancer earlier in life were more likely to eventually develop cancer. Diabetes was 2.4 times more likely to occur in patients who were diagnosed with cancer before the age of five than those who were diagnosed in their late teens.
Doctors are still struggling to understand the link between cancer treatment and diabetes. One theory is that irradiation damages the pancreas, which is responsible for manufacturing and secreting insulin. Radiation may also alter hormones, resulting in insulin resistance.