The present invention relates to prognostic methods which are useful inmedicine, particularly cancer chemotherapy. The object of the invention toprovide a method for assessing GST -pi expression levels in fixed or fixed andparaffin embedded tissues and prognosticate the probable resistance orsensitivity of a patient's tumor to treatment with platinum-based therapies byexamination of the amount of GST -pi mRNA in a patient's tumor cells andcomparing it to a predetermined threshold expression level. More specifically,the invention provides to oligonucleotide primer pair GST-piand methodscomprising their use for detecting levels of GST-pi mRNA.