A Genotype Study of the C-Ha-Ras-1 Locus in Human Bladder Tumors

Biomarkers in bladder cancer: translational and clinical implications

Bladder cancer is associated with high recurrence and mortality rates. These tumors show vast heterogeneity reflected by diverse morphologic manifestations and various molecular alterations associated with these disease phenotypes. Biomarkers that prospectively evaluate disease aggressiveness, progression risk, probability of recurrence and overall prognosis would improve patient care. Integration of molecular markers with conventional pathologic staging of bladder cancers may refine clinical decision making for the selection of adjuvant and salvage therapy. In the past decade, numerous bladder cancer biomarkers have been identified, including various tumor suppressor genes, oncogenes, growth factors, growth factor receptors, hormone receptors, proliferation and apoptosis markers, cell adhesion molecules, stromal factors, and oncoproteins. Recognition of two distinct pathways for urothelial carcinogenesis represents a major advance in the understanding and management of this disease. Nomograms for combining results from multiple biomarkers have been proposed to increase the accuracy of clinical predictions. The scope of this review is to summarize the major biomarker findings that may have translational and clinical implications.

Molecular prognostication in bladder cancer--a current perspective

The optimal management of bladder cancer depends on the accurate assessment of the tumour's biological potential. Advances in molecular biology and cytogenetics have spurred intense research in identifying and characterising prognostic markers for patients with transitional cell carcinoma (TCC) of the bladder. The molecular changes that occur can be categorised into (1) chromosomal alterations leading to carcinogenesis, (2) cellular proliferation as a result of dysregulation of cell cycle control, and (3) growth control processes such as angiogenesis leading to metastasis. The accumulation of these changes ultimately determines a tumour's clinical behaviour and response to therapy. As the understanding of bladder cancer evolves, novel molecular markers for prognostication will make their way from the research laboratory to the clinical setting with the promise to improve patient care and outcomes.

HRAS1 variable number of tandem repeats polymorphism and risk of bladder cancer

The HRAS1 variable number of tandem repeats (VNTR) polymorphism, 1 kb downstream from the HRAS1 gene, has been reported to be associated with risk of various cancers. To examine whether individuals with rare HRAS1 VNTR alleles are at increased risk of bladder cancer we carried out a case control study with 230 bladder cancer cases and 203 hospital-based controls frequency-matched on ethnicity, gender and age. For genotyping we used a PCR-based long-gel electrophoretic assay that provides precise allele size discrimination. We did not find evidence of a strong overall effect of the HRAS1 VNTR on bladder cancer risk. Genotype data for whites and blacks were analyzed separately, but the number of black subjects was too small to estimate meaningful odds ratios. Compared to white subjects with 2 common alleles, the odds ratio (OR) for white subjects with 1 rare allele was 0.9 (95% confidence interval (CI) = 0.5-1.4) and for those with 2 rare alleles OR = 1.7 (95% CI = 0.6-5.4). HRAS1 genotype may be related to the prognosis of bladder cancer, however, because incident cases, i.e., newly diagnosed cases had a higher frequency of rare alleles than did prevalent cases, i.e., cases already existing at the time of recruitment. Repeating the analyses with incident cases only (n = 53), the OR for subjects with 1 rare allele was 1.2 (95% CI = 0.6-2.4) and for those with 2 rare alleles 3.2 (95% CI = 0.8-13.7). The number of incident cases was too small to draw firm conclusions on a possible association with a subgroup of tumors with a poor prognosis. Published 2002 Wiley-Liss, Inc.

[Molecular biology in bladder cancer]

Progress of molecular biology with regard to etiopathogeny of tumours in general, and cancer of the bladder in particular, is taking place at such a vertiginous pace that practising urologists find themselves overwhelmed in terms of their ability to learn and keep updated in so complex a subject. The understanding of certain molecular factors with critical influence on the formation, growth and progression of a tumour of the bladder, is forcing us to make unbiased assessments on the role they will play in the evolution and survival of this neoplasia. It is anticipate they will be much more reliable than traditionally established morphological factors such as grade and stage. We also include a literature review with an analysis and elucidation of the role played by oncogenes, tumor suppressor genes, vascular density markers, telomerase etc., in the formation and growth of cancer of the bladder and their likely relationships with already established clinico-pathological factors.