Malignant Urinary Tract Neoplasm

Cancers of the urinary tract, particularly bladder cancer, are among the most common cancers affecting people worldwide, with thousands of new cases diagnosed each year and a strong tendency to return even after successful treatment.

Table of contents

• What is malignant urinary tract neoplasm?
• Types of urinary tract cancers
• Associated anatomy
• Who gets urinary tract cancer?
• Risk factors
• Signs and symptoms
• Diagnosis and testing
• Stages of bladder cancer
• Treatment approaches
• Recurrence and follow-up
• Coping with urinary tract cancer

What is malignant urinary tract neoplasm?

Malignant urinary tract neoplasm refers to cancerous tumors that develop in the tissues lining the urinary tract. The urinary tract includes the kidneys, ureters (tubes connecting kidneys to the bladder), bladder, and urethra (tube that carries urine out of the body). The tissues lining these organs contain specialized cells called urothelial cells or transitional cells, which can stretch and change shape^[3].

Bladder cancer is the most common type of urinary tract cancer and accounts for about 3% of new cancer cases. It is the second most common cancer of the urinary system^[3]. When cancer develops in the bladder, it can grow through the bladder wall into nearby tissues. If left untreated, it may spread to nearby lymph nodes and then to other parts of the body, including bones, lungs, or liver^[2].

Types of urinary tract cancers

More than 90% of urinary tract cancers are urothelial carcinomas, also known as transitional cell carcinomas. These cancers begin in the urothelial cells that line the inside of the urinary tract^[3]. Urothelial carcinoma is the type of bladder cancer that most patients are diagnosed with^[7].

Other less common types of bladder cancer include:

• Squamous cell carcinoma: This type starts in thin, flat cells that line the inside of the bladder. It accounts for about 5% of bladder cancers and typically develops in people who have had long periods of bladder inflammation or irritation^[2].
• Adenocarcinoma: This very rare type begins in gland cells that line organs, including the bladder. It accounts for only 1% to 2% of all bladder cancers^[2].
• Small cell carcinoma of the bladder: This is an extremely rare type that affects about 1,000 people in the United States^[2].

Bladder cancer can also be categorized by how deeply it has grown into the bladder wall. Non-invasive bladder cancer is found only in the inner lining of the bladder. Non-muscle-invasive cancer has grown deeper into the bladder but has not reached the muscle layer. Muscle-invasive bladder cancer has grown into the muscle wall of the bladder and may have spread to the fatty layers or tissues outside the bladder^[2].

Associated anatomy

• Bladder
• Kidneys
• Ureters
• Urethra
• Renal pelvis

The bladder is a hollow, balloon-shaped organ located in the lower part of the abdomen that stores urine. It has a muscular wall that allows it to expand to hold urine made by the kidneys and shrink to push urine out of the body^[5]. There are two kidneys, one on each side of the backbone above the waist. Tiny tubes in the kidneys filter and clean the blood, removing waste products and making urine. The urine passes from each kidney through a long tube called a ureter into the bladder, where it is stored until it leaves the body through the urethra^[5].

Who gets urinary tract cancer?

Bladder cancer is the sixth most prevalent cancer in the United States and the fourth most common cancer in males. Men are three to four times more likely to develop bladder cancer than women^[9]. However, women who do develop bladder cancer often have more advanced forms of the disease because they may not recognize the symptoms early^[2].

About 90% of people diagnosed with bladder cancer are older than 55 years, with an average age at diagnosis of 73 years^[9]. The average age of diagnosis is 65 years, with the disease being more frequent in men than women^[3].

Bladder cancer affects white people about two times more often than Black or Hispanic people. However, the disease is more likely to be diagnosed at an advanced stage in Black patients^[9].

Risk factors

Several factors can increase the risk of developing bladder cancer. Cigarette smoking is the strongest risk factor and is thought to be the cause of about half of all bladder cancers. Smokers are three times more likely to get bladder cancer than non-smokers^[1][3]. As the bladder works to filter harmful chemicals from cigarette smoke, it becomes damaged over time^[1].

Other established risk factors include:

• Older age, particularly over 55 years
• Male sex
• White race
• Occupational exposure to certain chemicals, particularly in chemical and textile industries^[3][9]
• Pelvic radiation therapy^[9]
• Use of certain medications, such as cyclophosphamide^[9]
• Chronic bladder infection or irritation^[9]
• Personal or family history of bladder cancer^[9]
• Long-term use of indwelling catheters^[9]

Studies have also suggested associations with diabetes, obesity, and use of the diabetes medication pioglitazone for more than one year^[9]. Consuming large amounts of processed red meat may also slightly increase risk^[9].

Signs and symptoms

The most common symptom of bladder cancer is blood in the urine, which appears in 85% to 90% of patients. This is usually painless and may come and go^[3][9]. Many bladder cancer symptoms are also seen with other less serious conditions, but they should not be ignored^[5].

Warning signs that may indicate bladder cancer include:

• Blood in the urine (may be visible or detected only through testing)
• Frequent urination
• Painful urination
• Back pain
• Difficulty urinating or weak urine stream
• Urinary storage symptoms, particularly with high-grade tumors^[3]

If any of these symptoms are present, it is important to see a doctor. The doctor may first investigate more common causes of the symptoms or may refer the patient to a specialist such as a urologist or oncologist^[1].

Diagnosis and testing

When bladder cancer is suspected, several tests may be used to confirm the diagnosis and determine how far the cancer has spread. The most common initial test is cystoscopy, which should be performed in all patients with visible blood in urine, all patients 35 years and older who have microscopic blood in urine, and all patients with unexplained urinary symptoms regardless of age^[9].

During cystoscopy, a thin tube with a light and camera is inserted through the urethra into the bladder, allowing the doctor to view the inside of the bladder and look for abnormal areas^[7].

Other diagnostic tests may include:

• Urine tests to look for blood or cancer cells
• Imaging of the upper urinary tract, preferably using computed tomography (CT) scan^[9]
• Kidney function tests
• Transurethral resection of bladder tumor (TURBT), which allows for definitive diagnosis, staging, and primary treatment^[9]
• Biopsy to examine tissue samples under a microscope

The diagnosis will determine the type of cancer cells present, the grade (how abnormal the cells look), and the stage (how far the cancer has spread). These factors are all used to determine the best treatment approach^[7].

Stages of bladder cancer

The stage of bladder cancer refers to how far it has spread. Understanding the stage is important because it helps doctors plan the most appropriate treatment^[5].

Bladder cancer is commonly divided into stages based on how deeply it has grown into the bladder wall:

• Stage 0 (Non-invasive): Cancer is found only on or near the surface of the bladder lining and has not invaded deeper layers^[6].
• Stage I: Cancer has grown into the connective tissue layer beneath the bladder lining but has not reached the muscle layer^[6].
• Stages II and III (Muscle-invasive): Cancer has grown into the muscle wall of the bladder and may have spread to the fat surrounding the bladder or to nearby organs^[6].
• Stage IV (Advanced): Cancer has spread to the lymph nodes or to distant parts of the body such as bones, liver, or lungs.

Bladder cancers are also graded as low-grade or high-grade. High-grade cancers are more aggressive and more likely to invade the bladder wall and spread to other parts of the body^[7].

Treatment approaches

Treatment for bladder cancer depends on several factors, including the type of cancer, the grade, the stage, and the patient’s overall health^[1].

Surgery

Surgery is the main treatment for bladder cancer^[15]. For early-stage cancer, surgery may involve removing the cancer from the bladder lining through a procedure called transurethral resection. For more advanced cancer, surgery may involve removing part or all of the bladder and creating a new way for urine to leave the body^[15].

Chemotherapy

Chemotherapy uses medicine to kill cancer cells. It may be given before surgery or radiation therapy, at the same time as radiation therapy, or after surgery to prevent cancer from returning^[15]. For bladder cancer, chemotherapy can be delivered directly into the bladder through a catheter or given intravenously so it travels throughout the body^[15].

For non-muscle-invasive disease, treatment typically involves transurethral resection followed by chemotherapy or immunotherapy placed directly into the bladder^[9][13].

For muscle-invasive bladder cancer, treatment generally includes chemotherapy with cisplatin-based drugs given before surgery, followed by removal of the bladder or radiation therapy. This approach provides an absolute five-year survival benefit of 5% to 8%^[9].

Immunotherapy

Immunotherapy helps the immune system find and kill cancer cells. BCG (bacille Calmette-Guérin) is a type of immunotherapy commonly used for non-muscle-invasive bladder cancer. It is placed directly into the bladder^[15].

Radiation therapy

Radiation therapy uses rays of radiation to kill cancer cells. It may be used instead of surgery or combined with chemotherapy for muscle-invasive bladder cancer^[15].

Targeted medicines

Targeted medicines work to stop cancer cells from growing. They may be used when there is a higher chance of cancer returning after surgery, when chemotherapy causes severe side effects, or when cancer has spread to other parts of the body^[15].

Recurrence and follow-up

Bladder cancer has a strong tendency to come back even after successful treatment. Healthcare providers can treat early-stage bladder cancer effectively, but about 75% of early-stage bladder cancers return after treatment^[2]. Evidence suggests that non-muscle-invasive bladder cancers have recurrence rates up to 70% within two years of treatment^[20].

Because of the high recurrence rate, it is important for people who have been treated for bladder cancer to visit their doctor regularly for follow-up exams and tests. This ongoing surveillance is a key part of management, and primary care physicians often play an important role in ensuring adequate ongoing monitoring^[3].

Follow-up care typically includes regular cystoscopy exams and urine tests to check for signs that cancer has returned. The frequency of these tests depends on the stage and grade of the original cancer^[18].

Coping with urinary tract cancer

A diagnosis of bladder cancer can bring many emotional and physical challenges. Many people experience fear, anxiety, shock, anger, or uncertainty when first told they have cancer^[19]. These feelings are natural and may come and go over time.

Emotional support

Getting information about the disease and its treatment can help patients feel more in control and better able to make decisions. It is important to ask doctors and nurses to explain things again if needed^[19]. Talking with family, friends, or other people who have had similar experiences can also provide support. Many patients find it helpful to speak with a counselor or join a support group^[19].

Physical adjustments

Some treatments for bladder cancer can cause physical changes that affect daily life. For people who have surgery to create a urostomy (an opening in the abdomen for urine drainage), learning to manage the urostomy bag and catheter takes time. While adjusting to these changes can be difficult, many people are eventually able to do most of what they did before surgery^[22].

Managing fear of recurrence

Fear that cancer will come back is one of the most common concerns for survivors. This fear may be particularly strong before follow-up appointments or when waiting for test results^[22]. Learning about the disease, understanding individual risk, and knowing what can be done to reduce risk can help manage these fears^[20].

Healthy lifestyle

After treatment, taking steps to protect bladder health may help reduce the risk of recurrence. Important steps include quitting smoking, staying well hydrated by drinking six to eight glasses of water daily, eating a diet rich in fruits and vegetables, and getting regular exercise^[20]. Even 30 minutes a day of moderate exercise can reduce anxiety and symptoms such as fatigue, nausea, and pain^[20].