Asian Hematology Research Journal

Background: Chronic myeloid leukaemia (CML) is classically reported with a modest male predominance in Western registries. Several African reports, however, suggest a reversed or attenuated sex ratio. We examined the sex distribution and sex-related differences in baseline characteristics in a ten-year cohort of patients with CML in Southern Nigeria.

Methods: We retrospectively analysed 35 patients with CML (21 females, 14 males). Age, packed cell volume (PCV), white blood cell count (WBC) and platelet count at presentation were compared between sexes using Welch's t-test and the Mann-Whitney U test; categorical severity distributions were compared with chi-square or Fisher's exact tests; effect sizes were estimated as Cohen's d; and logistic regression was used to assess factors associated with female sex.

Results: Female patients constituted 60.0% of the cohort (male-to-female ratio 1:1.5). There were no statistically significant differences between the sexes in age (30.1 ± 2.4 vs 31.1 ± 3.5 years; p = 0.375), PCV (p = 0.800), WBC (p = 0.813) or platelet count (p = 0.761), and effect sizes were negligible (|d| ≤ 0.12) except a small difference in age (d = −0.34). Severity distributions of anaemia, leucocytosis and thrombocytopenia did not differ by sex, and no variable was statistically associated with female sex in univariate or multivariable logistic regression.

Conclusion: This Southern Nigerian cohort showed a female majority without sex-related differences in disease severity at presentation. The observed female preponderance may reflect demographic and health-seeking factors rather than biological sex differences and warrants confirmation in larger prospective studies.