Bladder preservation with tri-modality therapy
We learn more about bladder preservation with tri-modality therapy in treatment of bladder cancer.
Bladder cancer is the most common malignancy of the urinary system, with an estimated 550 000 new cases worldwide as reported in 20181.
Patients with bladder cancer typically present with gross or microscopic haematuria (blood in urine). Though, symptoms such as a change in urination frequency, urgency, pain or discomfort when urinating, or waking up during the night because you need to urinate frequently may be initial signs of bladder cancer.
Risk factors, diagnosis and staging of bladder cancer
Risk factors include exposure to chemical carcinogens, cigarette smoking, chronic urinary tract infections, viruses like human papillomavirus (HPV), and genetic predisposition, such as lynch syndrome 2-5.
Most bladder cancer diagnoses are early stage cancers and urothelial bladder cancer is the most common type of bladder cancer.
The spectrum of urothelial bladder cancer at presentation includes non-muscle invasive (found in the inner layer cells of the bladder and don’t invade the muscular wall), muscle invasive (cancer spreads into the detrusor muscle of the bladder), and metastatic disease (spreads to different sites of the body). The extent of disease determines treatment and prognosis.
Surgery
Radical cystectomy (removal of the urinary bladder) remains the cornerstone of curative treatment for muscle-invasive bladder cancer.
Urothelial bladder cancer involves the removal of the bladder (in combination with removal of the uterus, ovaries, fallopian tubes and possibly a portion of the vagina in women and the prostate and seminal vesicles in men), pelvic lymph node dissection, and reconstruction of the urinary tract6-8.
Tri-modality therapy
Tri-modality therapy, which includes surgery and chemo-radiation, can be used in muscle-invasive urothelial bladder cancer to preserve the bladder with good functional outcomes.
This consists of a trans urethral resection of bladder tumour (TURBT), followed by chemo-radiation in patients who are poor candidates for radical cystectomy due to medical co-morbidities or for those patients who wish to maintain their bladder.
TURBT is a surgical procedure that removes a tumour in the bladder though the urethra. The urethra is a tube that carries urine from the bladder to the outside of the body.
Radiation
Radiation therapy (RT) may be given as either a split-course or continuous-course approach.
During the split course, halfway through radiation, the urologist does a restaging cystoscopy (endoscopy of the urinary bladder via the urethra) with repeat biopsies to assess if the patient is responding to treatment.
In a continuous-course approach, cystoscopy and biopsy is done after chemo-radiation is complete. There are no trials comparing these two approaches, and the choice of approach is based upon institutional expertise and preferences9-12.
Conformal three-dimensional RT techniques, especially more advanced techniques, including intensity-modulated radiation therapy (IMRT), are now widely used whenever possible.
These highly conformal techniques allow more accurate delivery of the required high-dose of radiation to the tumour and adjacent areas at risk. An adequate dose of radiation is required to eradicate all of the tumour and to treat adjacent areas of the bladder that are at high-risk for local recurrence.
At the same time, careful attention is required to minimise the dose of radiation to adjacent normal tissues that are more radiosensitive (colon, rectum, small intestine, hips, and normal bladder) and are at risk for significant toxicity.
The most common long-term side effects of tri-modality therapy are urinary, gastrointestinal and sexual dysfunction.
Salvage cystectomy ( removal of the urinary bladder) is indicated for patients who don’t have complete response to this combined-modality approach or who develop an invasive recurrence during follow-up cystoscopic surveillance.
Final thought
Tri-modality therapy is a good, feasible therapeutic option and results in a low rate of acute and late toxicity. Most long-term survivors will retain fully functional bladders. Post-therapy surveillance remains a critical component of bladder preservation with tri-modality therapy.
MEET THE EXPERT – Dr Nirasha Chiranjan
Dr Nirasha Chiranjan is a radiation oncologist. Her special interests are the breast, gynaecological, head and neck, and central nervous system cancers. She is based at the Life Flora Hospital, Sandton Oncology (Morningside) and Ahmed Kathrada Cancer Institute. (cancersa.co.za/nirasha)
References:
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[11]Perdonà S, Autorino R, Damiano R, et al. Bladder-sparing, combined-modality approach for muscle-invasive bladder cancer: a multi-institutional, long-term experience. Cancer 2008; 112:75.
[12]Mak RH, Hunt D, Shipley WU, et al. Long-term outcomes in patients with muscle-invasive bladder cancer after selective bladder-preserving combined-modality therapy: a pooled analysis of Radiation Therapy Oncology Group protocols 8802, 8903, 9506, 9706, 9906, and 0233. J Clin Oncol 2014; 32:3801.