DETECTION OF EPIDERMAL GROWTH-FACTOR RECEPTOR AND C-ERBB-2 GENE AMPLIFICATION IN TRANSITIONAL-CELL BLADDER-CARCINOMA USING THE DIFFERENTIALPCR TECHNIQUE

Amplification of genes associated with cell control and differentiatio n is found in many human tumours and its detection may have important value in predicting tumour progression. In this study we examined 72 D NA samples extracted from paraffin-fixed formalin-embedded transitiona l cell carcinomas with a novel differential PCR technique that can det ect variations in gene dosage using small amounts of tumour DNA. We ha ve observed that this technique under certain conditions has many adva ntages over traditional gene analysis techniques. Our study revealed E GF-r and c-erbB-2 gene amplification in 2/72 (3%) and 11/72 (15%) blad der carcinomas, respectively. EGF-r gene was amplified in 2/24 (8%) gr ade III carcinomas while c-erbB-2 was amplified in 2/25 (8%) and 9/24 (37.5%) grade II and grade III carcinomas, respectively. All cases wit h EGF-r and c-erbB-2 gene increased copy number were classified as inv asive on the basis of muscularis propia invasion. The association betw een c-erbB-2 amplification and tumour grade as well as stage of the ca rcinomas was statistically significant indicating direct linkage to bl adder carcinoma progression, while the relationship between EGF-r gene amplification and the above mentioned parameters did not reach signif icance.