The reality of cancer treatment in a developing country: the effects of delayed TKI treatment on survival, cytogenetic and molecular responses in chronic myeloid leukaemia patients.

Cancer patients in developing and low-income countries have limited access to target therapies. For example, tyrosine kinase inhibitor (TKI) therapy for chronic myeloid leukaemia patients (CML) is often delayed. In Bosnia, 16% of patients received immediate TKI treatment (<3months of diagnosis), while 66% of patients received therapy after a median 14-month wait period. To assess the effect of delayed treatment on outcome, three patient groups were studied according to the time they received TKI treatment (0-5months, 6-12months and >13months delay). The primary endpoints were complete cytogenetic (CCyR) and major molecular response (MMR) at 12months. At 12months of therapy, CCyR and MMR rates on imatinib decreased significantly: CCyR was achieved in 67% of patients in the immediate imatinib treatment group, 18% of patients in 6-12months group and 15% of patients in >13months wait group. MMR rates at 12months occurred in 10% of patients with immediate treatment, 6% of those in 6-12months group and 0% of patients in >13months wait group. However, CCyR and MMR rates in patients on nilotinib were not associated with duration of treatment delay. Our data suggests that the deleterious effect of a prolonged TKI therapy delay may be ameliorated by the more active TKI nilotinib.