Non-Muscle Invasive Bladder Cancer

There are several different types of bladder cancer, but the most common type is called urothelial carcinoma (sometimes referred to as transitional cell carcinoma). In the United States, approximately 9 out of 10 adults diagnosed with bladder cancer have this form of the disease.^1,2

The specific type of bladder cancer a person has depends on the specific cells where the cancer first begins to grow. As cancer cells multiply, they can form one or more tumors along the inner surface of the bladder.^1,2

Cancer that grows in the lining of the bladder

Urothelial carcinoma starts in a tissue layer called the urothelium. The bladder is a hollow, flexible, muscular organ in the lower abdomen that expands to hold urine. The urothelium is a thin inner lining of cells that directly coats the interior walls of the bladder. This lining is the most common site where bladder cancer cells originate.^1,2

What does non-muscle-invasive mean?

Around three-quarters of people diagnosed with urothelial carcinoma have non-muscle-invasive bladder cancer (NMIBC). This means that the cancer cells are confined to the innermost layers of the bladder—either in the urothelium or the lamina propria (a very thin layer of connective tissue directly beneath the urothelium)—and have not grown into the deeper muscular wall of the bladder. Bladder cancer that has grown into the muscle layer is classified as muscle-invasive bladder cancer.^1,2

Understanding risk categories and low-grade intermediate-risk NMIBC

Not all non-muscle-invasive bladder cancers behave the same way. To guide treatment planning, healthcare providers classify NMIBC into distinct risk categories—low risk, intermediate risk, or high risk—based on factors such as tumor size, tumor count, recurrence history, and cellular grade:^2,3

• Grade: Refers to how abnormal the cancer cells look under a microscope. Low-grade cancer cells look relatively similar to normal cells and tend to grow slowly, making them less likely to spread into deeper tissues
• Risk Level: Estimates the likelihood that the tumor will return (recur) or grow into deeper layers (progress).

Patients diagnosed with low-grade intermediate-risk NMIBC (LG-IR-NMIBC) have low-grade cells, but possess clinical characteristics that raise their risk of recurrence. These characteristics often include:^2,3

• Having multiple tumors present in the bladder.
• Having a single tumor larger than 3 centimeters.
• Experiencing early or frequent tumor recurrences (e.g., a tumor returning within 12 months).

Identifying your specific risk profile helps your care team select the treatment and monitoring strategy best suited to your condition.

Diagnosing non-muscle-invasive bladder cancer

The most common symptom of bladder cancer is blood in the urine (hematuria), which may cause urine to look pink, red, or dark brown. Other common symptoms include:^1,2

• Needing to urinate more frequently than usual
• Pain or burning sensation during urination
• Feeling a sudden, urgent need to urinate

These symptoms can also be caused by non-cancerous conditions, such as urinary tract infections or bladder stones, and some people with NMIBC experience no symptoms at all. However, it is essential to consult a healthcare provider if you experience any of these signs, as bladder cancer treatment is most effective when started early.^1,2

Diagnostic tests and cystoscopy

If your healthcare provider suspects bladder cancer, they will perform a physical examination and order tests on your urine to check for signs of infection or abnormal cells.^1,2

If further evaluation is needed, your doctor will perform a cystoscopy. During this procedure, a thin, flexible tube with a tiny light and camera (a cystoscope) is inserted through the urethra (the tube that carries urine out of the body) into the bladder. This allows the provider to inspect the bladder lining directly and take small tissue samples (biopsies) or remove suspicious areas for lab testing.^1,2

Treating non-muscle invasive bladder cancer

Treatment for non-muscle-invasive bladder cancer is tailored to the stage, grade, and risk group of the tumor, as well as the patient's overall health.^2,3

Transurethral resection of bladder tumor (TURBT)

Most patients diagnosed with NMIBC undergo a surgical procedure called transurethral resection of bladder tumor (TURBT). During TURBT, a surgeon inserts an instrument through the urethra into the bladder to remove visible tumors and trim or cauterize the underlying tissue layer.^1-3

Intravesical therapy

Because NMIBC tumors have a notable tendency to return, doctors often recommend intravesical therapy following surgery. Instead of taking medicine by mouth or through a vein, intravesical treatments deliver liquid medication directly into the bladder using a catheter. This allows the medicine to treat cancer cells locally with minimal impact on the rest of the body.^2-4

• Intravesical chemotherapy: Chemotherapy agents (such as gemcitabine or mitomycin) may be instilled into the bladder shortly after TURBT to destroy remaining microscopic cancer cells and lower the risk of recurrence.
• Chemoablative hydrogels: For patients with recurrent low-grade intermediate-risk NMIBC, specialized intravesical formulations—such as reverse-thermal hydrogels containing chemotherapy—may be used to deliver medication locally and keep it in contact with the bladder lining for an extended period.
• Intravesical immunotherapy: Bacillus Calmette-Guérin (BCG) is an immunotherapy agent made from a weakened bacterium. When placed in the bladder, it triggers the body's immune system to target and destroy bladder cancer cells.

Prognosis and long-term surveillance

The overall outlook for non-muscle-invasive bladder cancer is generally favorable, and death from NMIBC following appropriate treatment is uncommon.^1,2

However, NMIBC—particularly intermediate-risk forms—frequently recurs over a person's lifetime. Because of this, ongoing surveillance is a vital part of care. Patients undergo regular follow-up visits, typically involving cystoscopy and urine tests scheduled every few months initially, to detect any returning tumors as early as possible.^2,3