Bladder Cancer is the second most common urological malignancy and the eighth most common cancer in the United Kingdom (UK). The spectrum of bladder cancer includes non-muscle invasive, muscle invasive and metastatic disease. Each behaves differently clinically and therefore prognosis and treatment are unique to each individual classification.
- Worldwide 356,600 cases of bladder cancer are diagnosed each year - 10,300 of which are diagnosed in the UK.
- Clear geographic discrepancies exist in the incidence of bladder cancer and developing countries tend to display significantly higher rates of incidence.
- Bladder Cancer is the 7th most common cancer in men and the 17th most common cancer in women ( male to female ratio 4:1).
- 90% of patients with bladder cancer present over the age of 55 years old. The peak age of presentation is 65-69 in men and 75-79 in women.
- Cigarette smoking is the most significant risk factor associated with bladder cancer and can be identified as a causative agent in 50% of male cases and 35% of female cases.
- Occupational exposure to urothelial carcinogens accounts for 5-20% of all bladder cancers - this link has been attributed to the aromatic hydrocarbon alanine.
- Further aetiological factors of note include; radiotherapy, chronic inflammation - persistent UTI's and certain drugs e.g. cyclophosphamide.
The bladder has 4 layers; the innermost transitional cell layer - which lines the whole urinary tract, the lamina propria, the muscularis mucoasa and the adventitia.
Most bladder cancers arise form the transitional cell layer. Other rarer subtypes of bladder cancer include squamous cell and adenocarcinomas . Secondary carcinomas tend to be adenocarcinomas metastising generally from the prostate, colon, uterus and ovaries. In areas where schistosomiasis is prevalent up to 75 % of bladder cancers are squamous in nature.
Staging and Grading
Staging and grading systems in oncology provide clinicians with valuable prognostic information with regards to progression, recurrence and survival.
The staging system used in bladder cancer is the tumour - node - metastases system (TNM). Under this system bladder cancer can be considered as non-muscle invasive ( Tis-Ta-T1) or muscle invasive ( T2-T3-T4).
At diagnosis 5% of patients will have metastatic disease, 25% will have muscle invasive disease and 70% will have non-muscle-invasive disease.
Traditionally bladder cancer has been graded in relation to the World Health Organisations ( WHO) 1973 criteria, however in 2004 a new grading criteria was established by the WHO and the International Society of Urological Pathology (ISUP). The 2004 criteria aims to produce a more standardised and accurate representation of risk potential however the European Association of Urology (EAU) guidelines recommend that both criteria are used by clinicians until further validation of the 2004 criteria is achieved in clinical trials.
The classic presenting symptom of bladder cancer is painless haematuria. Haematuria is a common symptom and the risk of the underlying pathology being cancer varies with age, sex and type of haematuria. Patients with macroscopic haematuria in the absence of infection should be referred under the Cancer 2-Week Wait to Urology, patients over the age of 50 with significant microscopic haematuria can also be referred under this scheme.
Patients with bladder cancer may also present with:
- Voiding symptoms ( frequency, urgency, dysuria)
- Abdominal Pain
- Weight Loss
- Urinary Incontinence
- Full abdominal , rectal and or vaginal exams should be undertaken. Physical examination is usually insignificant although in locally advanced disease a pelvic mass may be felt.
Upper tract Imaging
- In patients over the age of 40 CT urography is the imaging mode of choice to evaluate upper tract disease.
- In patients under the age of 40 it is more common to use intravenous urography (IVU) or ultrasound to investigate for upper tract disease.
- May show malignant cells.
- The gold-standard diagnostic modality in bladder cancer is cystoscopy. Following cystoscopy, diagnosis is based on biopsy of lesions and histological evaluation of tissue.
CT and MR imaging
- Should be used to stage muscle invasive bladder cancer.
Four types of standard treatment options are used in the management of bladder cancer. The most appropriate treatment is based on the stage and grade of the cancer.
1) Surgery is used to treat most stages of bladder cancer.
- Trans-urethral resection (TUR) allows superficial leisions to be burned away with high energy electricity via diathermy attached to a cystoscope.
- Radical cystectomy ( surgical removal of the bladder and any lymph nodes or nearby organs that contain cancer) with urinary diversion can be undertaken to treat muscle-invasive and some high grade bladder cancers.
- Radiotherapy can be used as an alternative to surgery in individuals who are not suitable for surgery and also for palliative care in advanced cases of bladder cancer.
- All patients with non-muscle invasive bladder cancer should receive an immediate instillation of intravesical chemotherapy e.g. mitomycin C following initial TUR.
- Neo-adjuvant platinum based chemotherapy should be considered in patients with muscle invasive bladder cancer - although debate still exists around its merit in this setting.
- BCG ( Bacillus Calmette-Guerin) , a live attenuated strain of mycobacterium bovis is a highly effective intravesical agent in the treatment of superficial bladder cancer and when used appropriately has been shown to reduce both progression and recurrence of tumours.