Increased Diabetes Risk in Hodgkin Lymphoma Survivors

Hodgkin lymphoma survivors who were treated with infradiaphragmatic radiotherapy have an increased risk of developing diabetes mellitus, says a new study.

Hodgkin lymphoma (HL) survivors who were treated with infradiaphragmatic radiotherapy have an increased risk of developing diabetes mellitus, according to a new study. The finding suggests screening for diabetes in these patients may be warranted.

“Changes in treatment over the past decades have resulted in 10-year survival rates of 80%, leading to a large cohort of HL survivors with a long life expectancy,” wrote study authors led by Flora E. van Leeuwen, PhD, of the Netherlands Cancer Institute in Amsterdam. “However, radiotherapy (RT) and chemotherapy given for HL may cause severe late effects, such as second neoplasms and cardiovascular diseases.”

The authors studied a cohort of 2,264 5-year HL survivors, all diagnosed before the age of 51 years and treated between 1965 and 1995. The median follow-up for the cohort was 21.5 years, over which time 157 patients developed diabetes mellitus. Results were published online ahead of print in August in the Journal of Clinical Oncology.

The overall 30-year incidence of diabetes in this cohort was 8.3%. However, in patients who underwent para-aortic radiation therapy with at least 36 Gy, the 30-year incidence of diabetes was 14.2%, compared with only 6.1% in those who did not undergo radiation therapy. A multivariable analysis showed that those treated with para-aortic and splenic radiotherapy had a significantly increased risk for diabetes compared to those not treated with any radiotherapy, with a hazard ratio (HR) of 2.28 (95% CI, 1.53-3.38; P < .001). There was also an increased risk for those treated with ≥ 36 Gy compared with those treated with 10-35 Gy, with an HR of 2.04 (95% CI, 1.20-3.44; P = .014).

The study also compared these patients to the general population, and found that those treated with 10-35 Gy did not have a significantly increased risk of developing diabetes. HL survivors who were treated aboved that 36 Gy threshold, however, had an HR for developing diabetes compared with the general population of 2.58 (95% CI, 1.74-3.68). This corresponded to 39 excess cases per 10,000 person-years. The biggest increase in risk was observed in patients who were treated for HL before the age of 25.

Though the precise mechanism for this increase in diabetes risk is unclear, the authors wrote that damage to the insulin-producing cells located in the tail of the pancreas could play a roll.

“Treating physicians should be aware of the increased risk of diabetes mellitus among HL survivors treated with para-aortic radiotherapy,” the authors concluded. “Diabetes mellitus screening should be considered in HL follow-up guidelines for patients treated with abdominal radiotherapy. Early detection of diabetes mellitus may contribute to a substantial reduction of morbidity in long-term survivors of HL.”