The invention relates to a method for detection of decreased susceptibility for anticancer adjuvant chemotherapy with cytostatic from the group of oxazaphosphorines and antibiotic from the group of anthracyclines in breast cancer patients, according to which the evaluation of PIP gene expression is performed with the use of real-time PCR method on the isolated total RNA in the sample of tissue material taken from patient from primary tumour of ductal breast cancer, wherein the statistically significant lower expression of PIP mRNA indicates decreased susceptibility for anticancer adjuvant chemotherapy with cytostatic from the group of oxazaphosphorines and antibiotic from the group of anthracyclines. The invention provides a prediction test, which enables rapid classification of patients in terms of their responsiveness for adjuvant chemotherapy and thus the undertaking of appropriate therapeutic intervention.
