Double- and competitive-differential PCR for gene dosage quantitation

An association of a loss of DNA replication control and the activation of erbB oncogenes can be deduced from studies with different cancers (1-5). In the first study on ovarian cancer 26% of the tumors had c-erbB-2 amplifications (6). The correlation between c-erbB-2 amplification and expression on mRNA and protein level was perfect. The median survival time of patients with ovarian cancers was negatively correlated to the degree of amplification. The association of egfr (c-erbB-1) amplification and overexpression with ovarian cancer prognosis has not been investigated as extensively as for c-erbB-2. EGF-R is expressed in normal ovarian epithelium and patients whose ovarian cancer continues to express EGF-R have a worse prognosis (7). Rearrangements of the egfr gene in ovarian cancer were also described, as identified by Southern blot analysis (8). Bauknecht submitted that a failure of chemotherapy was seen for ovarian cancers with low EGF-R expression (8).