Application of Haematological Parameters in Monitoring Treatment Response in Patients with Chronic Myeloid Leukaemia at a Cancer Centre in Ogun State, South West Nigeria

Chronic myeloid leukaemia management has been transformed by tyrosine kinase inhibitors, with haematological monitoring playing a central role in assessing treatment response and guiding therapeutic decisions. This study evaluated the application of haematological parameters in monitoring treatment response in CML patients at Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun State, South West Nigeria. A retrospective longitudinal study reviewed medical and laboratory records of 60 CML patients initiated on imatinib therapy over a five-year period. Full blood count parameters, differential leucocyte counts, peripheral blood film morphology, and BCR-ABL transcript levels were assessed at diagnosis, at three months, six months, and twelve months of treatment. At diagnosis, all patients had leucocytosis with median white blood cell count of 186 x10 to the 9 per litre. By three months, 68.3% achieved complete haematological response defined by normalisation of blood counts. BCR-ABL transcript levels at three months correlated strongly with subsequent molecular response. Thrombocytopaenia and neutropaenia were the most common haematological toxicities. Failure to achieve haematological response at three months was significantly associated with disease progression. The study reinforces the indispensable role of sequential haematological monitoring alongside molecular testing in CML management and recommends establishment of formal CML haematological response monitoring protocols at cancer centres across South West Nigeria. Keywords: chronic myeloid leukaemia, haematological response, imatinib, BCR-ABL, treatment monitoring