Transfusion Dependence and Serum Ferritin Predict Worse Outcomes in MDS, but Not Transferrin Saturation

Iron overload is linked to higher rates of complications and mortality in patients with myelodysplastic syndromes (MDS). Increased serum ferritin, however, may not be the most accurate metric of true iron overload. Research presented at the 62nd ASH Annual Meeting & Exposition explored whether higher transferrin saturation (TSAT) correlates with ferritin levels and whether TSAT can help predict clinical outcomes, such as survival, infectious death, and cardiac death.

Presenter Jennifer Teichman, MD, of the University of Toronto in Canada said the study retrospectively evaluated data from 718 adult patients in the Canadian national MDS registry at 15 centers.

Data included means, medians, and ranges of ferritin levels and TSAT at roughly six-month intervals. The researchers evaluated changes in ferritin levels and TSAT over time. The study also collected information on transfusion density, defined as total number of units transfused divided by months elapsed since transfusion dependence began. The researchers then compared and contrasted survival differences.

At a median follow-up of 2.1 years:

• 17% of the patients had developed acute myeloid leukemia (AML).
• 56% had experienced infections (median, two per patient).
• 7% had experienced a cardiac event.
• 43% had been hospitalized at least once.
• 61% of patients had died.

The known causes of death were grouped as follows:

• AML: 26%
• Progressive disease: 20%
• Infection: 19%
• Cardiac causes: 10%
• Bleeding: 6%

Ferritin increased in all patients from baseline to 42 months, but TSAT remained stable over time. Therefore, Dr. Teichman said, the two were only moderately correlated over time.

Transfusion dependence remained stable over time, and it was significantly associated with infectious deaths but not cardiac events.

TSAT was not significantly associated with five-year overall survival (OS), leukemia-free survival (LFS), progression-free survival (PFS), or cardiac events. But ferritin level was significantly associated with five-year OS and PFS, just not with LFS or cardiac events.

“Further analyses to probe these relationships are ongoing, including the effect of TSAT and iron chelation therapy on infectious deaths,” Dr. Teichman said.