Patients and Methods
This study was conducted at PH and African Institute of Biomedical
Science and Technology (AiBST) laboratory. We included all the patients
who met the inclusion criteria into the study. Inclusion criteria were;
women aged 18 years and above with histologically proven breast cancer
diagnosis, willingness to participate in the study and attend study
follow-up visits as well as have been prescribed doxorubicin based
chemotherapy but not received the first. The exclusion criteria were;
non-black women, prior treatment with any chemotherapy and patients with
prior chest wall radiotherapy. Five milliliter of whole blood was
collected from each patient who met the inclusion criteria by
venipuncture at entry and stored at the Zimbabwe repository. Two hundred
microliters of the whole blood was used to extract DNA using Kingfisher
flex Magnetic Particle Processor. Genomic DNA was extracted using the
Applied Biosytems MagMAX DNA Multi-Sample Ultra 2.0 Kit using an
automated system (King FisherFlex Magnetic Particle Processor System).
The extracted DNA was quantified using Qubit, dsDNA BR (broad range)
Assay Kit and run on the Invitrogen Qubit 4 Fluorometer according to the
manufacturer’s protocols. Fifty ng/µl was the recommended amount of DNA
for genotyping by manufacturer hence nuclease free water was used to
normalize the DNA to this recommended concentration. The extracted DNA
was stored at either -20°C short term or -80°C long term before
analysis. Written informed consent was obtained from all patients or
legal guardians. The study was approved by the ethics committees of PH.