Hodgkin’s disease survivors face a more than six-fold increased risk of developing acute myeloid leukemia (AML), which is highest in the 10 years after Hodgkin’s diagnosis, a large study shows.

Hodgkin’s disease is a cancer of the body’s lymphatic system that typically affects people between 15 and 40 years of age and those over 55 years of age. Due to advances in the diagnosis and treatment of this cancer, survival rates are high. AML, by contrast, is a cancer of white blood cells that usually affects people in their mid-60s and carries a worse prognosis than Hodgkin’s disease.

The current findings also indicate that the elevated risk of AML in Hodgkin’s survivors has decreased significantly since 1984, probably due to changes in treatment, but it has not been eliminated.

The risk of AML in Hodgkin’s survivors compared with the risk in the general population is known to be substantially increased, Dr. Sara J. Schonfeld of the National Cancer Institute and colleagues note, but no large study has looked specifically at the excess absolute risk of AML in these patients while addressing factors such as age and year of diagnosis.

As reported in the Journal of the National Cancer Institute, Schonfeld and her team looked at 35,511 one-year survivors of Hodgkin’s disease included in 14 European and North American cancer registries who had been diagnosed with the disease between 1970 and 2001.

Two hundred seventeen patients developed AML, while 10.8 cases would have been expected, for an excess absolute risk of 6.2. Excess absolute risk was 7.9 in the first 10 years of Hodgkin’s diagnosis, 4.6 from 10 to 14 years, and 1.3 by 15 years after diagnosis.

The researchers also found that excess absolute risk of AML was higher among patients who were 35 or older when they were diagnosed with Hodgkin’s lymphoma compared with those who were younger. Patients diagnosed between 1970 and 1984 also had a greater excess absolute risk of AML than patients diagnosed between 1985 and 2001.

This difference was particularly pronounced for patients who had been treated with chemotherapy initially.

The chronological decrease in AML risk is likely due to changes in chemotherapy, Schonfeld and her colleagues suggest. “Analytic studies with detailed treatment data are required to correlate these decreases with changes in therapy and to better understand the long-term risk of AML after Hodgkin’s lymphoma,” they conclude.

SOURCE: Journal of the National Cancer Institute, January 1, 2006.