[The amplification of c-myc, N-ras, c-erb B oncogenes in ovarian malignancies]

In this study, [a-32p]dATP labelled probes of c-myc, N-ras and c-erb B genes were employed to perform dot blot hybridisation with DNA extracted from 17 cases of primary ovarian cancer, 3 cases of recurrent ovarian cancer, 2 cases of germ cell ovarian cancer, 5 cases of serous cysadonoma and 4 cases of normal ovarian tissue. Some specimens were examined by Southern blot hybridisation. The results showed varying degrees of amplification: c-myc 54.5%, N-ras 64.1% and c-erb B 31.8%, in the 22 cases of ovarian malignancies. All were significantly higher than in the three benign tumours and in normal ovarian tissue. Frequency of amplification of more than 2 oncogencis at the same time was found to be 40.9%. There was a negative correlation between amplification of c-myc and differentiation. A relatively high amplification of N-ras was present in late stage ovarian cancer. Patients with c-erb B amplification showed a shorter survival period than those without amplification.