Cytogenetics
Morphological | the results of conventional cytogenetic techniques and Comparative Genomic Hybridisation (CGH) show that the two types of endometrial carcinoma differ by their karyotypic features : endometrioid carcinomas are characterised by relatively simple chromosome aberrations whereas serous carcinomas show complex abnormalities endometrioid carcinomas are generally slightly hyperdiploid; chromosome gains concern mainly the long arm of chromosome 1 (70 % of the cases) through isochromosomes or unbalanced translocations; it can be observed as sole abnormality; trisomies 10 (40 % of the cases), 2, 7, and 12 are, in decreasing order, the most frequently associated abnormalities; trisomy 10 can exist as sole imbalance; loss of chromosome 22 has also been recurrently observed; Comparative Genomic Hybridization (CGH) confirms the low rate of copy number changes (mean of 1,5 aberrations per tumour); it roughly shows the same imbalances, and, in addition, gains of 8q (18 % of cases), and of the region 13q21-->qter (3 cases); loss of chromosome 22 has not be detected using this method; high level amplification was found in 3 cases, in 1q and in 6p due to their low incidence and to the complexity of their chromosome abnormalities serous carcinomas are less documented; a CGH sudy, carried out on 24 case showed a higher rate of chromosome imbalances (mean of 5,7 aberrations per tumour); the most frequent regions of gain were 3q26.1-->qter (50 % of cases), 8q (33 %), and 1q, 2q, 5p, 6p; high level amplifications were found in 30 % of the cases in 2q, 3q, 5p, 6p, 8q, 15q, 18 p and 18q, 20 The distinct patterns of chromosome changes observed in serous and endometrioid carcinomas suggest that these two types belong to two genetic entities. A comparison of these results with those of a CGH study of serous ovarian carcinoma (cited in 5) shows that the serous endometrial carcinoma should be genetically related to this tumour. |