Chromosome imbalance in endometrial adenocarcinoma.

The results of karyotypic analysis by R-banding after short-term culture of eight new cases of endometrial adenocarcinomas are presented and compared to previously published data. Among a total of 25 cases reported that had a diploid or near-diploid chromosome number, 72% contained a trisomy or tetrasomy 1q, often as the only abnormality. An excess of the long arm of chromosome 1 is, therefore, shown to be the predominant feature of endometrial adenocarcinoma. Trisomies 10, 2, 7, and 12 were, in decreasing order, the most frequently associated abnormalities, but trisomy 10, found in 40% of the cases, can also exist as the only imbalance. Because breakpoints in chromosome 1 are generally centromeric, a position effect with oncogene activation seems unlikely. It is suggested that the observed chromosome imbalances are secondary and are the result of the adaptation of the cancer cell to disturbed metabolic pathways.