Clinical Features and Outcomes of 666 Cases with Therapy-Related Myelodysplastic Syndrome (t-MDS).

Therapy-related myelodysplastic syndrome (t-MDS) is a serious complication of chemoradiotherapy for primary diseases. This cohort was aimed to determine the clinical features and outcomes of t-MDS in comparison with de novo MDS. I retrieved data of 666 cases with t-MDS, and 29,703 cases with de novo MDS diagnosed between 2001 and 2012 from the database of U.S. National Cancer Institute. Survival curves were estimated, and Cox proportional hazards model was constructed. Compared with patients with de novo MDS, patients with t-MDS tended to be young (median age; 65 vs. 76 years, p < 0.001), and were more likely to be female-sex (51.4 vs. 44.7%, p = 0.001). Median overall survival (OS) and 5-year OS rate are significantly poorer in t-MDS than de novo MDS (17.2 months and 22% vs. 31 months and 32%, respectively, p < .001). In t-MDS cases, with a median follow-up of 16 months (range 1-143 months), 521 cases (78.2%) had died. Of which, 78 (15%) cases had died from acute myeloid leukemia, and 66 (12.7%) cases had died from solid cancers. Of the total 66 cases died from solid cancers; 19 cases (28.8%) died from cancer of lung/bronchus, 11 cases (16.7%) breast cancers, and 10 cases (15.2%) ovarian cancer. In a multivariate analysis adjusted for clinical features, calendar period and radiotherapy, the hazard of mortality was significantly low in de novo MDS compared with t-MDS (hazard ratio 0.59; p < .001). In conclusions, t-MDS is a distinct entity of MDS in terms of clinical characteristics and prognosis.