Detection of non-papillary, non-invasive transitional cell G1 carcinoma as revealed by increased DNA instability and other cancer markers.

The method to reveal DNA-instability as demonstrated by immunohistochemical staining with anti-cytidine antibody after acid hydrolysis (DNA-instability test) was used as a marker of malignancy. The test was applied to paraffin-embedded sections taken from 15 urinary bladders, renal pelvic cavities, and ureters bearing multiple carcinoma in situ (CIS) and totally 31 papillary urothelial cancers. The serial sections of the same tissues were also subjected to immunohistochemical staining for PCNA, p53, DFF45, and VEGF. The DNA-instability test was positive in 100% cancer lesions irrespective of the grades, and apparently normal urothelium, and hyperplastic and dysplastic urothelial lesions also showed the areas with clones positively stained with DNA-instability testing, and the percent numbers of positive areas in them were 28.3%, 37.7%, and 61.5%, respectively. These clones, which were present in apparently normal urothelium and in hyperplastic and dysplastic urothelial lesions, showed higher percent values of PCNA-positive-cells, in comparison to the values estimated in the areas with negatively stained DNA-instability testing, and the former values were statistically not different from those in carcinoma lesions. Furthermore, the percent numbers of areas positive for p53, DFF45, and VEGF, with positive DNA-instability testing were also much higher than those with negative DNA-instability testing in apparently normal urothelium, and hyperplastic and dysplastic urothelial lesions, and the former values were again comparable to those in cancer lesions with no statistical differences. These clones were regarded as already being malignant and should be the direct precursors of progressed cancer lesions. They will make progression through two different pathways, one to papillary non-invasive G1 cancers by neovascularization induced by paracrine secretion of VEGF, and another to flat CIS G2 without secretion of VEGF; thus the clones should be regarded as non-papillary, non-invasive Gl TCC, or CIS G1. It should be always taken into account that the probability for apparently normal urothelium, and hyperplastic and dysplastic urothelial lesions to contain cancer clones, will be high already, especially in tumor-bearing bladders.