The bladder is a balloon-shaped organ in the pelvis that holds urine. Bladder cancer is a type of cancer that develops in the bladder. It typically begins to form in the cells that line the inside of the bladder, which mutate and grow abnormally, resulting in a tumor. Bladder cancer is typically found in individuals over 55 years of age and is more commonly seen in men.

What causes bladder cancer?

While the exact cause of bladder cancer isn’t clear, the condition has been linked to risk factors including:

  • Smoking
  • A personal and/or family history of bladder cancer
  • Birth defects
  • Certain medications
  • Chemical exposure (e.g., arsenic, industrial dye chemicals)
  • Chronic bladder inflammation
  • Parasitic infection
  • Prior chemotherapy or radiation therapy

What are the types of bladder cancer?

The type of cell that cancer originates in defines the type of bladder cancer. As a result, treatments for bladder cancer may vary.

Bladder cancers are broken down into two categories based on how far they have spread into the wall of the bladder:

  • Non-invasive cancers still reside within the walls of the bladder and have not spread into deeper layers.
  • Invasive cancers grow into deeper layers of the bladder wall. They are more likely to spread and are more difficult to treat.
  • Superficial (non-muscle invasive) cancers include non-invasive tumors as well as invasive tumors that have not penetrated into the muscle layer of the bladder.

Types of bladder cancer include:

  • Adenocarcinoma – This cancer forms in cells that make up the mucus-secreting glands located in the bladder. Adenocarcinoma is rare in the U.S., and almost all adenocarcinomas are invasive.
  • Squamous cell carcinoma (SCC) – SCC is a type of cancer more commonly found in parts of the world where a specific parasitic infection known as schistosomiasis is the primary cause of bladder infections. Squamous cells appear in the bladder as a response to the infection and may become cancerous over time. In the majority of cases, SCC is an invasive cancer.
  • Transitional cell carcinoma (TCC) – Also known as urothelial carcinoma, TCC occurs in the cells that line the bladder and is considered to be the most common type of bladder cancer in the U.S. These are the cells that expand and contract when the bladder fills and empties. They also line the inside of the uterus and urethra.

How is bladder cancer diagnosed?

Tests to confirm a diagnosis of bladder cancer may include:

  • Cystoscopy — A thin tube with a camera is inserted into the urethra to examine the inside of the urethra and bladder. During the procedure, the physician may take a sample or biopsy for testing.
  • Urine cytology — A sample of urine is analyzed for the presence of cancer cells.
  • Imaging tests — Imaging tests such as a special type of X-ray (known as an intravenous pyelogram) or a computed tomography (CT) scan may be used to view the different parts and tissues of the urologic tract.

Once the diagnosis is confirmed, additional tests may be required, including:

  • Bone scan
  • Chest X-ray
  • CT scan
  • Magnetic resonance imaging (MRI)

Next, the stage of the bladder cancer is determined. Staging is based on:

  • How invasive the cancer is
  • If the cancer is present in the lymph nodes
  • If the cancer has spread or metastasized to other organs
  • Tumor size

Stages of bladder cancer are:

  • Stage 0 (Ta and Tis): Cancer cells are found only on the inner lining of the bladder. Lymph nodes are not involved, and cancer has not spread or metastasized. This is also called superficial cancer or carcinoma in situ.
  • Stage I (T1): Cancer cells are found deep in the lining of the bladder but have not invaded the bladder muscle. Lymph nodes are not involved, and cancer has not spread.
  • Stage II (T2): Cancer cells are present in the muscle layer of the bladder.
  • Stage III (T3a and T3b): Cancer cells have spread through the bladder muscle into the tissues around the bladder, such as the prostate or the uterus.
  • Stage IV (T4): Cancer may have spread to lymph nodes and has spread to the prostate in men and to the uterus or vagina in women, or to the pelvic or abdominal wall in either gender.

How is bladder cancer treated?

Treatment for bladder cancer depends on multiple factors, including:

  • Overall health
  • Stage of cancer
  • Treatment preferences
  • Type of cancer