Primary Myelodysplastic Syndromes: The Mayo Clinic Experience With 1000 Patients

To share our 25 years of experience with patients with primary myelodysplastic syndromes (MDS) and to describe the natural history of the disease including presenting clinical and laboratory characteristics and long-term disease outcomes.

One thousand consecutive patients with primary MDS evaluated at Mayo Clinic between January 1, 1989, and May 1, 2014, were considered. The Revised International Prognostic Scoring System and other risk models were applied for risk stratification. Separate analyses were conducted for patients diagnosed before 2005 (n=531) and after 2005 (n=469).

Eighty-five percent of patients were older than 60 years (median age, 72 years), with 69% being men. The median follow-up period was 27 months (range, 0-300 months), during which time 808 (81%) deaths and 129 (13%) leukemic transformations were documented. Median survival and leukemic transformation rates were similar in patients diagnosed before or after 2005, despite the significantly higher use of hypomethylating agents in the latter group: 33 months vs 28 months (P=.46) and 13% vs 10% (P=.92), respectively. Revised International Prognostic Scoring System risk distribution was similar in patients diagnosed before or after 2005 (P=.23): 17% were categorized as very low, 36% low, 21% intermediate, 15% high, and 11% very high risk, with a median survival of 72, 43, 24, 18, and 7 months, respectively (P<.001). We found Revised International Prognostic Scoring System cytogenetic risk categorization to be suboptimal in its performance, whereas contemporary prognostic models were broadly similar in their performance.

The poor outcome in patients with MDS does not appear to have improved over time. Current risk stratification systems for MDS are not substantially different from each other. There is a dire need for drugs that are truly disease modifying and risk models that incorporate prognostically relevant mutations.