The purpose of treatment is to alleviate the burden of morbidity and reduce mortality, therefore treatment-associated
risks are of great interest. Surgical removal of breast tumour and chemotherapy are quite integral in halting disease
progress. However, these treatment strategies appear to be associated with the risk of activated coagulation. This
study purposively enrolled 60 female breast cancer patients consisting of 30 subjects each in pre-treatment and posttreatment
groups at a tertiary hospital in Nigeria. The Quick’s One-stage method was used for PT and APTT tests,
while enzyme-linked immunosorbent assay was used for D-Dimer assessment. Data analysis was carried out on
statistical package for social sciences (SPSS) version 20.0. A p-value ≤ 0.05 was considered significant. Mean values
of PT, APTT and D-Dimer of breast cancer patients were compared to values from control subjects. The PT was
significantly prolonged in the breast cancer patients compared to that of controls (p = 0.009). D-Dimer was also
significantly raised in the breast cancer patients compared to the value for controls (p = 0.001). The breast cancer
patients were further categorized into pre-treatment and post-treatment groups. All measured parameters were
observed to be more significantly (p = 0.001) deranged in the post-treatment group compared to the pre-treatment
group. This study concludes that there is evidence of increased thrombotic risk in breast cancer, particularly among
those who have undergone surgical and chemotherapeutic treatment