No abstract

Many patients with primary myelofibrosis (PMF) become red blood cell (RBC) transfusion dependent (TD), risking iron overload (IOL). Iron chelation therapy (ICT) may decrease the risk of haemosiderosis associated organ dysfunction, though its benefit in PMF is undefined. To assess the effect of TD and ICT on survival in PMF, we retrospectively reviewed 41 patients. Clinical data were collected from the database and by chart review. The median age at PMF diagnosis was 64 (range 43-86) years. Median white blood cell (WBC) count at diagnosis was 7.6 (range 1.2-70.9) x 10(9)/L; haemoglobin 104 (62-145) G/L; platelets 300 (38-2088) x 10(9)/L. Lille, Strasser, Mayo and International Prognostic System (IPS) scores were: low risk, n = 15, 8, 11, 3; intermediate, n = 15, 19, 9, 16; high, n = 5, 11, 5, 7; respectively. Primary PMF treatment was: supportive care, n = 23; hydroxyurea, n = 10; immunomodulatory, n = 4; splenectomy, n = 2. Sixteen patients were RBC transfusion independent (TI) and 25 TD; of these 10 received ICT for a median of 18.3 (0.1-117) months. Pre-ICT ferritin levels were a median of 2318 (range 263-8400) and at follow up 1571 (1005-3211 microg/L (p = 0.01). In an analysis of TD patients, factors significant for overall survival (OS) were: WBC count at diagnosis (p = 0.002); monocyte count (p = 0.0001); Mayo score (p = 0.05); IPS (p = 0.02); number of RBC units (NRBCU) transfused (p = 0.02) and ICT (p = 0.003). In a multivariate analysis, significant factors were: NRBCU (p = 0.001) and ICT (p = 0.0001). Five year OS for TI, TD-ICT and TD-NO ICT were: 100, 89 and 34%, respectively (p = 0.003). The hazard ratio (HR) for receiving >20 RBCU was 7.6 (95% Confidence Intervals [CI] 1.2-49.3) and for ICT was 0.15 (0.03-0.77). In conclusion, 61% of PMF patients developed RBC-TD which portended inferior OS; however patients receiving ICT had comparatively improved OS, suggesting a clinical benefit. Prospective studies of IOL and the impact of ICT in PMF are warranted.

Patients (pts) with MDS and iron overload often receive iron chelation therapy (ICT), although there are no data demonstrating that this improves clinical outcome. Pts with thalassemia receiving ICT do have improved survival and a decrease in number of end-organ toxicities. We performed a retrospective review of 178 pts seen at St.Paul’s Hospital in Vancouver, Canada, from January 1981 to April 2006, with a bone marrow diagnosis (Dx) of MDS. Clinical data were collected from the practice database, the Iron Chelation Program of British Columbia database, and by chart review. Pts receiving ICT were treated with desferroxamine 0.5–3g by subcutaneous infusion over 12 hours, 5 days per week. 105 were male and 73 female. MDS Dx were: RA, n=36; RARS, n=42; RAEB, n=28; RAEB-t or AML, n=16, CMMoL, n=25; other, n=31. Age at Dx was a median of 69 (18–94) years. Median absolute neutrophil count (ANC) was 1.6 (33–155) G/l, hemoglobin (Hgb) 96.5 (33–155) G/l, and platelet count 115 (7–644) G/l. Cytogenetic analysis was available in 128 pts; low risk (as defined by the IPSS), n=85; intermediate, n=22; high, n=21. Calculation of IPSS score was feasible in 133 pts; low risk, n=44; int-1, n=55; int-2, n=17; high, n=17. An elevated ferritin level, defined as a serum ferritin of ≥ 2000 ug/ml, was found in 28 pts. Clinical evidence of iron overload was present in 22 pts; CHF with no other contributing factor n=5; liver disease n=18; endocrine dysfunction, n=4; other, n=4; biopsy or imaging evidence was available in 6 pts. Of 18 pts receiving ICT, median duration of ICT was 15 (0–37) months (mo) and reasons for initiating ICT were: elevated ferritin, n=13; clinical and biochemical evidence of iron overload, n=3; number of transfusions received, n=2. In ICT pts, median ferritin level pre-ICT was 4215 (1500–8400) and post-ICT was 2659 (567–5228). In non-ICT pts with elevated ferritin, median ferritin after Dx was 1647 (265–5009) ug/L and at recent follow up was 3188 (763–12723) ug/L. There was a trend toward higher initial ferritin level in ICT pts (p<0.07) and significantly lower post-ICT ferritin in ICT pts compared to follow up ferritin in non-ICT pts (p<0.003). Documented causes of death in non-ICT pts were AML, n=22; MDS-related, n= 21; infection/sepsis, n=18 and non-MDS related, n=10. Documented causes of death in ICT pts were AML, n=1; MDS related, n=1; iron overload, n=1. Kaplan-Meier analysis showed that median overall survival (OS) for all pts was 36 (0.7–255.9) mo. Age showed a trend toward significance for OS (p<0.1); other factors that were significant included IPSS score, (p<0.0001); Dx, (p<0.0001); number of red blood cell units transfused, (p<0.0001); occurrence of ≥1 serious infectious episode, (p< 0.002); AML transformation, (p<0.0001); MDS-directed treatment, (p<0.04); elevated ferritin, (p<0.004); clinical evidence of iron overload, (p<0.001); and ICT, (p<0.001). In Cox regression analysis, the only factors significant for OS were IPSS score (p<0.008) and ICT (p<0.02). For pts with low or int-1 IPSS, median OS for pts receiving ICT was not reached at 160 mo vs. 40.1 (0.7–224) mo for non-ICT pts (p<0.03). In conclusion, although we were not able to demonstrate a decrease in organ dysfunction in pts receiving ICT for MDS, there was a significant improvement in OS. These are to our knowledge the first data documenting improvement in clinical outcome in pts with MDS receiving ICT.

Myelodysplastic syndrome (MDS) is characterized by ineffective hematopoiesis and risk of progression to acute myeloid leukemia (AML). Many MDS patients (pts) require red blood cell (RBC) transfusions, risking iron overload (IOL)-related organ dysfunction. We previously showed in a multivariate analysis of 178 pts, improved survival in 18 pts with low and int-1 IPSS risk MDS and IOL receiving iron chelation therapy (ICT), and now examine the effect of ICT on AML-free survival (LFS). The effect of ICT on cytopenias and RBC transfusion requirements (TR); was also examined. To control for possible bias favoring ICT pts, a subgroup analysis was performed. Each of 18 ICT pts had a non-ICT control pt (CP) selected and these groups are matched for gender; neutrophil count (NC), platelet count (PLTC) and hemoglobin (Hb) at diagnosis (Dx); MDS subtype; no of cytopenias, karyotype; IPSS score; ECOG Performance Status; no of serious infections; initial ferritin level (FL); total RBC units (U) received; primary MDS treatment (Rx); and duration of follow-up (FU; all p=NS). Median age in ICT pts was 64 (range 32–70) years (y) vs. 78 (39–81)y for CP (p=0.04). Features of the 178 pts are previously reported. In a univariate analysis (n=178), factors significant for LFS were: MDS subtype; IPSS risk; increased FL; total RBCU transfused; ≥1 serious infection; and receipt of ICT (all p&lt;0.05). Factors significant for LFS in a multivariate analysis (n=178) were: IPSS score (p=0.0001) and receipt of ICT (p=0.03). For low and int-1 IPSS, median LFS was not reached (NR) at 226 months (mo) for ICT pts and 40 mo for non-ICT pts (n=76) and 4y LFS was 64% and 42% respectively (p=0.002). In the subgroup analysis comparing ICT pts to 18 CP with matched features, at a median FU of 51.4 (7.1–225.8) mo and 44.8 (10.1–224) mo respectively, median LFS was NR at 226 mo vs. 40 mo in CP, and 4y LFS was 64% and 49% respectively (p=0.009). Median OS for ICT pts was NR at 226 mo vs. 40.5 mo for CP, and 4y OS was 64% and 49% respectively (p=0.01). There were 5 deaths (28%) in ICT pts (cardiac/IOL, n=2; infection, n=1; other MDS-related, n=1; AML, n=1) and 15 (83%) in CP (other MDS-related, n=6; AML, n=4; bleeding, n=2; infection, n=2; MDS-unrelated, n=1). Although non-ICT pts were older, only 1 death was age-related and all others were from MDS. One ICT pt developed AML at 15 mo from MDS Dx as did 4 non-ICT pts (p=0.06) at a median of 35 (19–71) mo; 2 pts received chemotherapy and both died of progressive AML. In ICT pts, mean ± standard error of the mean (sem) initial/pre-ICT FL was higher than in CP (4038±627 vs. 1759±1108 ug/L respectively, p=0.09), and FU levels decreased for ICT pts (3070±411, p=0.09) but not for CP (2185±996 ug/L, p=NS). There was no difference between ICT pts and CP in mean ± sem initial (2.0±0.3 and 2.0±0.5) and FU (3.4±0.9 and 7.4±4) x109/L NC; initial (236±32 and 104±25) and FU (164±24 and 82±20) x109/L PLTC; or initial (2.6±0.3 and 3.0±0.5) and FU (4.2±0.5 and 4.3±0.9) RBC-TR (no RBCU/4wk; all p=NS). In conclusion, LFS and OS in MDS pts with IOL receiving ICT were improved compared to non-ICT control pts matched for baseline features. These results support findings in the larger cohort of MDS pts and suggest there may be a beneficial effect of ICT on AML transformation and OS. Prospective studies of ICT in MDS pts are warranted.