Translational research studies of erbB oncogenes: selection strategies for breast cancer treatment

Specific gene families, e.g. encoding members of signal transduction pathways, show a gene dosage sensitivity. We report on the determination of the gene dosages of egfr and c-erbB-2 in relation to the intratumoral concentration of the tyrosine kinase receptor protein EGFR and p185c-erbB-2 and the clinical outcome of breast cancer patients in a retrospective study. Prognostic unfavorable subgroups were determined in a life-table analysis by (a) an average gene copy number of egfr of less than 0.4 and greater than 1.6 and an intratumoral EGFR concentration of more than 56 fmol/mg, (b) an intratumoral p185c-erbB-2 concentration above 26 HNU/mg and (c) a quotient of egfr and c-erbB-2 average gene copy numbers of less than 0.15 and greater than 4.35.