Bladder cancer
Written by Ming Huay Chin
Last Reviewed: April 2019
Review Due: April 2020
DEFINITION
'malignant transformation and growth of the cells lining the bladder. 90% of bladder cancers are transitional cell carcinomas, but squamous cell carcinomas and adenocarcinomas can also occur'
AETIOLOGY
Smoking
Aromatic amines/hydrocarbons
Dye and rubber factories
Pelvic radiation
Chronic inflammation
Bladder stones
Long-term catheterisation
Schistosoma infection
SIGNS AND SYMPTOMS
Bladder tumours most commonly present with painless haematuria either microscopic or macroscopic.
Other symptoms include
Dysuria
Urinary frequency
Urinary urgency
Patients may also present with signs of obstruction or retention.
Patients may also have systemic symptoms such as weight loss.
PATHOPHYSIOLOGY
Carcinogens are concentrated and excreted in the urine. Collection of urine in the bladder causes the cells in the urinary tract to be exposed to these carcinogens, leading to malignant transformation of the cells lining the urinary tract.
Investigations
Urinalysis
Haematuria
Urine cytology
Malignant cells
Imaging
Cystoscopy: visualise bladder tumours
All patients with painless frank haematuria
CT urogram: detect upper tract involvement
CT (or MRI) abdomen and pelvis: staging (looking for metastasis)
TREATMENT
Treatment depends on the grade and extent of invasion of the bladder cancer. In most cases, an urgent transurethral resection of bladder tumour (TURBT) is carried out, and intravesical chemotherapy to reduce the risk of recurrence.
Low grade, non-muscle invasive bladder cancer (Ta)
TURBT + intravesical mitomycin C at the same time
Follow-up cystoscopy 3 months and then 12 months and discharge if no recurrence
If intermediate risk, follow-up cystoscopy at 3, 9, 18 months then yearly
If recurring <12 months, give course of 6 doses intravesical mitomycin C
High grade, non-muscle invasive bladder cancer (T1)
TURBT
Either intravesical BCG immunotherapy or radical cystectomy
Cystectomy if poor response to >2 sets BCG
Follow-up cystoscopy every 3 months for 2 years, then every 6 months for 2 years, then yearly
Muscle invasive bladder cancer (T2-T4)
Neoadjuvant chemotherapy
Radical cystectomy or radiotherapy
Follow-up: yearly imaging and monitoring of kidney function, cystoscopy every 3 months for 2 years, then 6 months for 2 years, then yearly
EPIDEMIOLOGY
Incidence in the UK is 800 cases per 100,000 people. Males are more commonly affected than females, where the M:F ratio is 2.5:1.
Prognosis
Staging and Grading
Bladder cancer is staged using the TNM classification. T describes how far the tumour has invaded the bladder tissues. N describes if there is lymph node involvement, and M is used to describe if the cancer has metastasised.
Bladder cancer is graded from 1-3. Grade 1 is well-differentiated and Grade 3 is poorly differentiated and most likely to progress to invasive disease.
Therefore, a bladder cancer may be described as T1G3, where the tumour has invaded the mucosa and histologically the cells are poorly differentiated.