Apparent correlation of sex chromosome loss and disease course in urothelial cancer.

In recent years, interest in the genetics of various solid tumours has increased dramatically. Over the last several years, our laboratory has pursued genetic studies of transitional cell carcinoma of the bladder. We have studied the cytogenetics and disease course of more than 100 patients, achieving successful cultures in more than 75%. In these patients, we observed the loss of a sex chromosome (either X or Y) with a frequency of 40%. We stratified patients with loss of sex chromosomes into three groups: 1) presence of markers or chromosome rearrangements, 2) aneuploidy without marker chromosomes, and 3) loss of a sex chromosome only. The relevancy of both the natural history and potential impact of sex chromosome loss to the disease course, including invasive potential, will be discussed in detail for each of the three groups.