Urothelial cancer | My Site 1

Transitional Cell Carcinoma

Introduction

Over 90% of bladder cancers are urothelial carcinomas, previously termed transitional cell carcinoma. The most common primary symptom is haematuria, or blood in the urine. The key to diagnosis is urinary cytology and then cystoscopy, which is a procedure where an endoscope or a thin, tube with a light and a camera at the tip, is inserted into the bladder via the urethra.

They can be classified by histology. Urothelial carcinoma accounts for 90% of bladder cancers. Squamous cell carcinomas account for around 5% of cancers and adenocarcinomas make up approximately 1%.

Bladder cancers can also be classified based on their invasiveness

Non-muscle-invasive bladder cancer make up approximately 75% of tumours while

Muscle-invasive bladder cancer is rarer and usually treated more aggressively with cystectomy, radical radiotherapy, or palliation.

Key risk factors for bladder cancer include smoking, male sex, age over 55 years, exposure to chemical carcinogens, specifically aromatic amines used in rubber and dye industries, and systemic chemotherapy.

As most of these carcinogens are concentrated and excreted in the urine, the bladder has a prolonged exposure. From what is described as the “field effect”, urothelial tumours can be multifocal and there may already be multiple tumours at presentation. However, keep in mind malignant transformation can arise anywhere in the urinary tract.

To investigate suspected urothelial carcinoma, consider urinary tests, cystoscopy, and further imaging. Urinalysis will detect haematuria but urine can also be sent for cytology and is most accurate for identifying high-grade cancer cells and carcinoma in situ.

Cystoscopy is key to making the diagnosis.

Well-differentiated tumours form papillary frond-like lesions, whereas more aggressive tumours form plaque-like lesions. Any tumour identified at rigid cystoscopy will require biopsy and potential resection.

Imaging can help stage cancer and characterise complications. Ultrasound examination may reveal hydronephrosis if there is ureteric involvement. CT scanning can indicate local spread into the bladder wall and characterise metastatic disease.

Management is dependent on staging and if the cancer is non-muscle invasive, locally invasive or metastatic.

In general, the initial management is surgical and usually aimed at complete removal of tumour tissue by cystoscopic transurethral resection.

Adjuvant therapy for higher risk patients might be given in the form of immediate post-operative intravesical chemotherapy and delayed intravesical (BCG) immunotherapy which is most commonly given intravesically ≥2 weeks after resection.

Other more invasive treatments include radical cystectomy. If performed, some method of urinary diversion is required. One option is an ileal conduit formation with urine draining via a urostomy.

For metastatic disease, chemotherapy agents like cisplatin are commonly used, as well as radiotherapy and immunotherapy like pembrolizumab.

The classic clinical feature is haematuria which is characteristically painless and intermittent. If bleeding is gross, clots may cause urethral obstruction resulting in acute urinary retention.

Moreover, tumours themselves can cause obstruction. Masses near the bladder neck may cause lower urinary tract symptoms while tumours arising near a ureteric orifice can obstruct urine coming from the kidneys, causing hydronephrosis.

Double A, Double B, double double C.

Aromatic

Amines

Blood

Block

Cystoscopy

Cystectomy

Chemotherapy

Cisplatin