Bladder Flashcards
How common is bladder cancer?
4th most common for men, 8th for women.
2nd most common GU cancer
What is the median age of dx and m:f ratio?
Median age 70y/o
M:F 3:1
What are the risk factors for bladder cancer?
- Smoking (RR 2-5 compared to non-smoker)
- Chemical exposure (industrial aromatic amines, polycyclic aromatic hydrocarbon, hair dye, chlorinated water,
arsenic) - Drugs (phenacetin-containing analgesia, cyclophosphamide)
- Schistosomiasis (a/w SCC instead of UC – lay ova in bladder epithelium, causes irritation)
- Chronic inflammation (chronic UTI, cystitis, stone)
- Radiation exposure
- HNPCC/ Lynch syndrome
What are the two hypotheses to explain the multifocality of bladder cancer?
Clonogenic hypothesis and Field change hypothesis
Describe the clonogenic hypothesis of multifocal bladder cancer
- Tumour as descendants of single transformed cell (monoclonal origin) that undergoes further genetic alteration, proliferates and spreads through the urothelial tract via intra-epithelial migration or intra-luminal seeding
- E.g. from smoking
Describe field change hypothesis of multifocal bladder cancer
- Urothelial cells undergo malignant transformation at multiple sites independently from local carcinogen exposure (polyclonal origin) and become the source of multifocal tumour
- E.g. local irritation e.g. from cyclophosphamide/ local recurrent UTI/ bladder stone
Macro features of Urothelial carcinoma
either flat, ulcerated, or papillary (sessile/ ulceration suggests HG)
What percentage of bladder cancers are Urothelial carcinoma?
> 90%
What is the micro appearance of Urothelial bladder cancer
atypical cells (spindle, pyramidal) invading basement membrane
What is the grading of urothelial carcinoma?
HG vs LG
based on: cytological atypia (polarity, nuclear size/ pleomorphism/ hyperchromatism), and
mitotic figure
What is the IHC of Urothelial carcinoma?
IHC: CK7+, CK20+, HMWCK+ (marker of urothelial origin), GATA3+, p63
What are the variants of Urothelial carcinoma associated with more aggressive behaviour?
Urothelial carcinoma with divergent differentiation
o Squamous/ basaloid
o Trophoblastic
- Nested
- Micropapillary
- Sarcomatoid
- Plasmacytoid
- Poorly differentiated with rich giant cells
What trial established 21Gy/3# QOD as non inferior to 35Gy/10# for symptomatic improvement in palliative bladder cancer?
MRC-BA09 Duchene G
PhIII RCT 1992-1997
What is the pathogenesis of Urothelial bladder cancer?
Arises from deletion of chromosome 9 then progresses though 2 divergent phenotypic pathways:
hyperplasia vs dysplasia
What type of urothelial cancer arises from the hyperplasia pathway? What proportion of total is this?
Low grade non invasive papillary tumour
70-80%
What type of urothelial carcinoma arises via the dysplasia pathway?
What proportion does this represent?
Cis becoming invasive high grade tumour
20-30%
Describe the process and mutation associated with the hyperplasia pathway in pathogenesis of Urothelial ca
- deletion in c/s 9 occurs
- Progress via hyperplasia to LG pTa tumour (70-80% of cases)
- Characterized by activating mutation in HRAS gene and FGFR3
What is the risk of non invasive recurrence and transformation to a high grade invasive tumour with a LG papillary non invasive tumour?
70% risk of non invasive recurrence
15% risk of transformation to invasive/high grade
Describe the pathogenesis of invasive high grade urothelial cancer.
What gene changes are associated with this?
- deletion of c/s 9
- Arise from flat dysplasia → HG CiS → to invasive cancer (20-30% of cases)
- Characterized by structural and functional defect in p53 and Rb tumour suppressor gene
What are the types of non invasive bladder changes that exist?
Dysplasia
Carcinoma in situ
Urothelial papilloma
Papillary urothelial neoplasm of low malignant potential
Non invasive papillary carcinoma (Ta)
What is the risk of progression of dysplasia to CiS?
20%
What is the macro appearance of CiS?
flat, grossly erythematous, no mass
What is the micro appearances of Cis?
flat lesion, epithelium often denuded, with large, irregular, hyperchromatic
nuclei, prominent nuclear pleomorphism, high N/C ratio, high mitotic figure
o Less important: loss of polarity, nuclear crowding, irregular thickness of
epithelium