DNA banding patterns in carcinoma of the bladder

With the introduction in 1970 of DNA staining techniques productive of specific banding patterns in each chromosome, detailed chromosomal morphology became apparent, and precise karyotyping was a reality. To study the banding patterns of malignant tumors, six moderately well-differentiated transitional cell carcinomas of the bladder subjected to the direct squash procedure were stained by the acid-saline-Giemsa technique. Chromosomes A-2, B-4, and D-13 showed the most consistent patterns. Two marker chromosomes characterized the six tumors: marker l, a long submetacentric, was present in 66% of the karyotypes and marker II, resembling a B-4, was present in 28%. These markers, coupled with the subtetraploid mode of the six tumors, were unique when compared with well-differentiated and poorly differentiated bladder carcinomas. Potentially, DNA banding provides a more accurate method of classification, including assay of invasiveness, of malignant neoplasms of the bladder.