Abstract
In the UK there is a paucity of epidemiological data on the chronic myeloproliferative disorders (CMPDs) and myelodysplastic syndromes (MDS). In contrast data on acute myeloid leukaemia is consistently collected, but morphological subtypes are rarely defined. We present the incidence and outcome of myeloid malignancies in an unselected population from the South Thames area, which comprises 5.4 million adult inhabitants.
A consensus registration form was designed in which haemato-oncologists from 27 Acute National Health Service Trusts prospectively identified and confirmed cases of myeloid malignancies between 1999 and 2000. The French, American and British classification system was used to define acute leukaemia and MDS (Eikelboom et al., 1996, Bennett et al., 1976, 1991). PT was defined according to the MRC PT1 criteria and diagnostic criteria for PV and IMF as defined by Pearson et al., (1996). Twice a year contributing haematologists validated their cases to ensure complete ascertainment of cases. Additional myeloid malignancies diagnosed outside haematology were ascertained and validated by the Thames Cancer registry (TCR) data collection officers. Registration forms were forwarded to the TCR for processing. Deaths from myeloid malignancies were identified by the Office of National Statistics, which records all cases nationally.
Statistical analyses: the direct method was used to calculate the age standardized incidence rate using the European standard population (ESP) as defined by Jensen et al., (1991). Kaplan-Meier survival curves were compared using log-rank tests.
Between 1999 and 2000 a total of 2,112 myeloid malignancies were registered of which 24% of cases were AML, 37% MDS and 39% CMPDs. Morphological subtypes were unspecified in 46.3% cases of AML, 27% cases of MDS and 17% of CMPDs. The median age was >70 years for all subtypes of myeloid malignancies with the exception of idiopathic myelofibrosis (median age 69 years) and chronic myeloid leukaemia (median age 51 years). The European age standardised incidence rate for AML was 3.00/100,000, MDS 3.47/100,000, chronic myelomonocytic leukaemia (CMML) 0.46/100,000, IMF 0.37/100,000, polycythamia vera 1.08/100,000, PT 1.65/100,000 and for CML 1.09/100,000. There was a significant male predominance for AML, CMML and MDS. Three year estimated overall survival (OS) for AML was 15%, MDS 45% (survival advantage observed for females), CMML 29%, IMF 48%, PV 60% and CML 50%. Three year survival was significantly different in patients aged less than 65 years compared to those aged 65 years or greater for AML (37% vs. 2%), MDS (66% vs.40%) and CML (74% vs. 17%) p<0.001 and for IMF (66% vs. 37%), PV (90% vs. 76%) and PT (94% vs. 75%) p<0.02. Median survival by the FAB classification for AML in patients aged 55 years or less ranged from 8 (M6) to 46 months (M3) and for MDS of all ages OS ranged from 7 (RAEBt) to 39 months (RA).
Incidence and outcomes for adults with MDS, CMPDs, and AML vary from that reported in Europe and the USA (Maynadie, 1996, Taylor et al, 1996, Messa et al., 1999). We believe this study accurately reflects the incidence and outcome for myeloid malignancies in the UK and provides a benchmark for future population studies
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