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Dr Mia Hugo gives us a brief overview of how bothersome bladders may become bladder cancer.
Where do we find bladder cancer?
Bladder cancer is a world traveller, with a special liking for high income countries (HICs). It accounts for 3% of global cancer diagnoses and it’s the 10th most common cancer worldwide. According to GLOBOCAN 2020 estimates for SA, bladder cancer is recorded as the 12th most common cancer.
Bladder cancer has an incidence rate that is three-times greater in HICs versus low-and-middle-income-countries (LMICs). Despite the higher incidence of bladder cancer in HICs, mortality rates are greater in LMICs, which highlights the need for earlier detection and treatment.
Bladder cancer stalks the silver foxes
While globally bladder cancer is the 10th most common cancer looking at all cases, it’s estimated to be the sixth most commonly diagnosed cancer in men accounting for 4.4% of total new cases.
A 2017 Global Burden of Disease study found that the prevalence of bladder cancer was three times higher in males than in females. The risk of bladder cancer increases with age, with the age-specific curves increasing steeply after the age of 50 years.
Risk factors for bladder cancer
Cigarette smoking is the most established risk factor for bladder cancer.7 Tobacco smoking causes 50-65% of male cases and 20-30% of female cases and the incidence of bladder cancer is directly related to the duration of smoking and the number of cigarettes smoked per day.
The good news is that there is an immediate decrease in the risk of bladder cancer in those who stopped smoking. The reduction was about 40% within one to four years of quitting smoking and 60% after 25 years of cessation. Encouraging people to stop smoking would result in the incidence of bladder cancer decreasing equally in men and women.
Occupational exposure is the second-most important risk factor for bladder cancer. Work-related cases accounted for 20-25% of all bladder cancer cases in several studies and it’s likely to occur in occupations in which dyes (except for hair dyes), rubbers, textiles, paints, leathers, and chemicals are used. The risk of bladder cancer due to occupational exposure to carcinogenic aromatic amines is significantly greater after 10 years or more of exposure; the mean latency period usually exceeds 30 years.
Bilharzia (schistosomiasis) still plays an important role in the pathogenesis of bladder cancer in LMICs.9 In SA, areas with endemic bilharzia are provinces, such as KwaZulu-Natal, Eastern Cape, Limpopo, North West, and Mpumalanga; they have a high incidence of squamous cell carcinoma of the bladder which is the subtype linked to chronic bilharzia infection.1
Pelvic ionizing radiation exposure is associated with an increased risk of bladder cancer. A weak association was also suggested for cyclophosphamide (chemotherapy agent) and pioglitazone (oral diabetic agent).
Don’t ignore the bothersome bladder
Most patients with bladder cancer (85%) present with painless blood in the urine. Some patients (around 25%) present with irritable bladder symptoms such as pain and needing to urinate often (frequency, urgency, dysuria, and nocturia). Late presenting symptoms can include suprapubic pain, urinary or rectal obstructive symptoms, swollen legs, bone pain, fatigue and loss of weight.
The pathway to diagnosis
Early diagnosis and appropriate management according to the stage is key in bladder cancer. Any blood in the urine or new irritable bladder symptoms should prompt a visit to the GP who in turn will refer the patient to a urologist for further investigation.
The gold standard to diagnose bladder cancer is a cystoscopy with a biopsy. The urologist looks at the bladder internally with a camera and takes a piece of the suspicious lesion.
Looking at the histology and staging, radiology classifies bladder cancer into three main groups namely non-muscle invasive bladder cancer (NMIBC), muscle invasive bladder cancer (MIBC) and metastatic urothelial cancer.
Non-muscle invasive bladder cancer
Approximately 75% of patients present with NMIBC, which is disease confined to the mucosa (Stage Ta, CIS) or submucosa (Stage T1). NMIBC has a five-year overall survival rate of approximately 90%, but a high rate of recurrence of about 60% when managed with surgical resection alone and a 15% rate of transformation to MIBC.
NMIBC is typically treated with transurethral resection of the bladder (TURB) (removal of tumour from the bladder through the urethra), usually in combination with intravesical instillations (drug administration into the urinary bladder via a catheter) of medications, such as bacillus calmette-guerin (BCG) or chemotherapy.8
Muscle invasive bladder cancer
MIBC involves disease which invades the bladder muscle (Stage T2), perivesical tissue (Stage T3), adjacent organs, pelvic or abdominal wall (Stage T4), and the regional lymph nodes near the bladder. MIBC tends to have a worse prognosis with a five-year survival rate of between 45-50% following radiation therapy or surgical treatment.12 Treatment typically involves neoadjuvant chemotherapy and radical cystectomy but for some patients trimodal treatment (maximum TURB, followed by concurrent chemotherapy and radiation) is also an option.
Metastatic bladder cancer treatment options include chemotherapy, immunotherapy and palliative radiation.
The management of bladder cancer is complex, with many different treatment options that fall within guidelines that need to be individualised for a specific patient, which is where the value of discussing bladder cancer cases in a multi-disciplinary uro-oncology meeting comes in.
MEET THE EXPERT – Dr Mia Hugo
Dr Mia Hugo works in private practice as a radiation oncologist. She participates in weekly multi-disciplinary oncology team meetings for breast, urology, gastrointestinal/gynaecological, and head and neck cancers. She provides radiation to patients at Wits Donald Gordon, Netcare Milpark, Pinehaven and Olivedale Hospitals, as well as at Busamed and 200 Rivonia Medical Centre.
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