What is the role of genetic analysis in the diagnosis of bladder cancer?

Updated: Nov 01, 2018
  • Author: Gary David Steinberg, MD, FACS; Chief Editor: Bradley Fields Schwartz, DO, FACS  more...
  • Print
Answer

Answer

The study of genetic aberrations commonly associated with urothelial carcinoma provides a more objective assessment for diagnosing and detecting recurrent disease. Homozygous loss of band 9p21, the site for the tumor suppressor gene P16, is a known early genetic event in the development of papillary carcinoma and urothelial carcinoma in situ (CIS). [10]  

Increased chromosomal instability and aneuploidy have been implicated in tumor progression. A study by Sokolova et al of 9 genetic markers for detecting urothelial carcinoma showed that polysomy of chromosomes 3, 7, and 17 and deletion of 9p21 were the most sensitive and specific markers, detecting 95% of recurrent urothelial carcinomas. [11] Halling et al established that a threshold of 5 or more cells with polysomy was 84% sensitive and 92% specific for detecting recurrent urothelial cancer. [10]  Tests for mutations in the FGFR3 oncogene may also hold promise for diagnosing and predicting recurrence. [4]   

For muscle-invasive bladder cancer (MIBC), a consensus on molecular classification has emerged.12 The consensus recognizes six molecular subgroup classes of MIBC, as follows:

  • Luminal papillary (LumP)
  • Luminal non-specified (LumNS)
  • Luminal unstable (LumU)
  • Stroma-rich
  • Basal/squamous (Ba/Sq)
  • Neuroendocrine-like (NE-like)

Differentiation patterns, oncogenic mechanisms, tumor micro-environments and histological and clinical associations are distinct for each of the six classes. However, research still needs to be conducted on the best clinical use of this classification.812


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!