Bladder cancer is predominantly urothelial carcinoma and ranks as the tenth most common malignancy worldwide, with an incidence approximately three to four times higher in men than in women. Smoking is the leading risk factor. Based on the depth of tumor invasion, bladder cancer is classified as non-muscle-invasive bladder cancer (NMIBC) or muscle-invasive bladder cancer (MIBC). Although NMIBC does not directly threaten life, the recurrence rate is as high as 50%–70%, necessitating long-term follow-up. MIBC, on the other hand, has a high propensity for metastasis, with a significantly reduced 5-year survival rate. Painless hematuria is the most critical early clue, and any unexplained gross hematuria warrants evaluation for possible bladder cancer.
· Smoking (attributable in approximately 50% of bladder cancer cases)
· Occupational exposure to aromatic amines (dyes, rubber, leather, paints, etc.)
· Chronic urinary tract infection and long-term indwelling catheterization
· History of cyclophosphamide chemotherapy or pelvic radiotherapy
· Schistosoma haematobium infection in endemic regions (associated with a high incidence of squamous cell carcinoma in Egypt)
· Arsenic contamination of drinking water and genetic susceptibility
Tobacco and industrial aromatic amine metabolites are excreted by the kidneys into the urine, where they come into prolonged direct contact with the urothelium, forming DNA adducts and inducing mutations in genes such as FGFR3, TP53, and HRAS. FGFR3 activating mutations are commonly found in low-grade, non-invasive tumors, whereas TP53 mutations or deletions are more frequently observed in high-grade muscle-invasive carcinoma. Chronic deposition of Schistosoma haematobium eggs leads to squamous metaplasia and persistent inflammation, which may subsequently progress to squamous cell carcinoma.
Approximately 85% of patients present with painless, intermittent gross hematuria throughout the entire urinary stream as the initial symptom. The hematuria often resolves spontaneously, creating a false impression of“self-healing.”Some patients experience bladder irritative symptoms, such as urinary frequency, urgency, and dysuria, which are particularly common in carcinoma in situ. Large tumors or blood clots may obstruct the bladder outlet, leading to urinary difficulty or acute urinary retention. In advanced stages, invasion of surrounding organs can result in pelvic pain, hydronephrosis, lower-extremity edema, and lower back pain.
· Surgery:For non-muscle-invasive bladder cancer, transurethral resection of bladder tumor (TURBT) is performed, and resection must extend into the muscularis propria to ensure accurate staging. For muscle-invasive bladder cancer, the standard treatment is radical cystectomy with pelvic lymph node dissection, followed by urinary diversion or orthotopic neobladder reconstruction.
· Minimally invasive therapy:Transurethral laser enucleation or laser vaporization allows for precise tumor resection with minimal bleeding and a low risk of perforation. Postoperative intravesical instillation of chemotherapy or immunotherapeutic agents significantly reduces the risk of recurrence and progression. For patients who are unable to tolerate radical surgery, maximal transurethral resection combined with subsequent multimodality therapy can be employed as a bladder-preserving approach. Endoscopic hemostasis, clot evacuation, and palliative transurethral resection are used for symptom control in advanced disease.
· Chemoradiotherapy:Cisplatin-based concurrent chemoradiotherapy is a key component of bladder-preserving strategies for muscle-invasive bladder cancer. Radiotherapy is also used for postoperative adjuvant treatment, local recurrence control, and palliative symptom relief for conditions such as bone metastases.
· Targeted and immunotherapy:FGFR inhibitors are used in advanced urothelial carcinoma harboring corresponding genetic alterations. Immune checkpoint inhibitors have demonstrated durable responses in platinum-refractory disease and as first-line maintenance therapy. Antibody-drug conjugates provide new options for later-line treatment.
· Other treatments:Regular cystoscopic surveillance and urine cytology monitoring are the cornerstones of postoperative management for non-muscle-invasive bladder cancer. Nutritional support and stoma care guidance help patients adapt to daily life.
Cystoscopy with biopsy is the definitive diagnostic modality, allowing direct visualization of tumor number, size, morphology, and location. Urine cytology and molecular tests such as fluorescence in situ hybridization (FISH) serve as adjunctive diagnostic tools, particularly for carcinoma in situ. Ultrasound and CT urography are used to evaluate the upper urinary tract for concurrent tumors. Magnetic resonance imaging (MRI) offers relatively high accuracy for local staging. High-risk individuals, such as long-term smokers and those with occupational exposure, should seek immediate medical attention if hematuria occurs.
