Trends in acute leukaemia incidence in adults in the Republic of Macedonia (1993-2003)--a descriptive epidemiological study.

OBJECTIVE: To analyse trends in incidence rates of acute leukaemia in patients aged 15 and over admitted to hospital. DESIGN: A descriptive epidemiological study. SETTING: University teaching hospital, Haematology Clinic, Skopje. RESULTS: The crude incidence rates of acute leukaemia in adults during this period increased substantially (p for overall trend < 0.001). The lowest crude incidence rates (CIR) were observed in 1996 (CIR = 1.64/100 000; 95% Confidence Interval CI = 1.1-2.4), while the highest were noted in 2003 (CIR = 3.76/100 000; 95% CI = 2.9-4.8). In 1993 the sex ratio of the incidence rates (males to females) was Rate Ratio (RR) = 2.23, while as of 2001 the association between sexes disappeared (RR = 1). The trend in males was not significant (p = 0.160), while in females it showed a monotonic increase that was highly significant (p < 0.001). CONCLUSIONS: During a short period of time (11 years) we have noted an increase in the incidence rates of acute leukaemia in our population aged 15 years and above. The study suggests that this could be due to increased risk in females, and in adults over 40 years. In addition, according to the census results in 1994 and 2002 the proportion of people aged 65 and above increased by 30.5% implying that this demographic change could account for part of the relative increase in the incidence rates of acute leukaemia. Further analytic studies are needed to address the possible causes of these changes. What is already known on this topic: The risk of acute leukaemia increases by age and it is higher in males than in females. What this study adds: The incidence rates are equal between the sexes; the increase in risk of acute leukemia in females could be due to environmental risk factor.