Bladder cancer that has spread into the muscle of the bladder or farther is called “muscle invasive bladder cancer.” This cancer tends to spread quickly, so the outlook for people living with the disease is poor.

An estimated 82,290 people in the United States will have bladder cancer diagnosed in 2023, according to the American Cancer Society. Overall, the rate of new bladder cancers has been decreasing.

Bladder cancer is staged according to how far it has spread. Bladder cancer is muscle invasive when it has spread through the bladder lining and into the bladder muscle, and it’s defined as stage 2 or beyond bladder cancer.

Keep reading to learn more about muscle invasive bladder cancer (MIBC). We’ll cover its symptoms, what causes it, and how it’s diagnosed and treated.

MIBC occurs when bladder cancer has started to grow into the bladder muscle. It’s estimated that about 25% of bladder cancers are MIBC at the time of diagnosis.

Once bladder cancer has spread into the bladder muscle, it can quickly spread farther.

Is muscle invasive bladder cancer curable?

MIBC is more difficult to treat than earlier stages of bladder cancer. While early aggressive treatment has the potential to get rid of the cancer, for many people the cancer will come back.

The most common symptom of any type of bladder cancer is blood in your urine. The blood can range from bright red to rusty in color.

Other symptoms of bladder cancer are:

The symptoms above may also be indications of a more common condition, such as a urinary tract infection (UTI). If you notice that your symptoms are frequent or persistent, it’s important to see a doctor to discuss them.

Symptoms that can indicate that bladder cancer has spread farther may include:

The exact cause of bladder cancer isn’t known, but cancer in general happens when cells have changes in their DNA that lead them to grow and divide uncontrollably.

The main risk factor for bladder cancer, including MIBC, is smoking. Exposure to second-hand smoke is also a risk factor. It’s estimated that smoking contributes to up to 50% of bladder tumors.

Some of the other risk factors for bladder cancer are:

  • a genetic predisposition due to a family history of bladder cancer
  • a genetic syndrome that increases bladder cancer risk
  • workplace exposures to carcinogens
  • certain types of chemotherapy or prior radiation to the pelvis
  • chronic infections or inflammation that could affect the bladder

Diagnosis of MIBC will begin with a doctor taking your medical history and doing a physical exam. Doctors may order lab tests, such as:

  • urinalysis, which tests for blood and a variety of other substances in your urine
  • urine culture to check for an infection
  • urine cytology or urine tumor marker tests, which check your urine for evidence of cancer

If the doctor suspects that you have bladder cancer, they may order further tests such as a cystoscopy or biopsy.

When a cystoscopy is performed, a doctor uses a thin tube with a light to see inside your bladder. With a biopsy, transurethral resection of bladder tumor (TURBT) may be performed in which a suspicious area is removed and checked for signs of cancer.

The results of your biopsy not only show if you have bladder cancer, but they can also let the doctor know how invasive or aggressive the cancer is.

When bladder cancer is classified as MIBC, it will be considered at least a stage 2 cancer. Further tests can determine if the cancer has spread past the bladder or into more distant tissues such as:

Treatment for MIBC typically involves neoadjuvant chemotherapy alongside concurrent radiation therapy to shrink the tumor before surgery.

The National Comprehensive Cancer Network’s guidelines for bladder cancer, which are widely used across accredited cancer centers, recommend one of the following options:

  • neoadjuvant cisplatin-based combination chemotherapy followed by radical cystectomy
  • cystectomy alone for those not eligible to receive cisplatin-based chemotherapy
  • bladder preservation with concurrent chemotherapy and radiation (chemoradiotherapy) followed by TURBT
  • radiation therapy or TURBT for people who aren’t candidates for cystectomy or chemoradiotherapy

Cancer recurrence prevention

If you’ve had a radical cystectomy and your cancer is at a high risk of coming back, a doctor may prescribe an immunotherapy drug like nivolumab (Opdivo), for up to a year following surgery. This adjuvant (postsurgery) treatment depends on your risk of cancer recurrence and whether you received cisplatin before surgery.

Cancer that has spread to distant areas

Cancer that has spread to distant areas of the body (metastasized) may be treated using one or a combination of the following methods:

  • radical cystectomy with urinary diversion
    • If the cancer has spread to distant sites, surgery would be focused on alleviating symptoms and improving quality of life (palliative).
  • chemotherapy
  • radiation therapy
  • immunotherapy
  • targeted therapy

MIBC is more likely to progress and spread quickly. As such, the outlook for people with MIBC is poor.

A 2020 review on MIBC treatment notes that the overall 5-year relative survival rate for MIBC is about 60% to 70%, but it also notes that about 50% of people develop metastatic disease despite having a radical cystectomy.

The table below shows the 5-year relative survival rates for all stages of bladder cancer, according to the Surveillance, Epidemiology, and End Results Program (SEER) database of the National Cancer Institute.

SEER stage5-year relative survival rate (%)
Cancer remains in the bladder lining only (in situ).96.7
Cancer remains in the bladder (localized).70.9
Cancer has spread to nearby tissues and lymph nodes (regional).39.2
Cancer has spread to more distant tissues (distant).8.3
all stages77.9

Factors that can influence the outlook for people with MIBC can include:

  • whether or not your cancer has spread beyond the bladder
  • the type of bladder cancer you have
  • the cancer’s grade, which is an assessment of how aggressive the cancer is likely to be
  • the type of treatment used and how your cancer responds to it
  • your age and overall health

MIBC is bladder cancer that has spread into the muscle of the bladder or farther, and it’s diagnosed as stage 2 or beyond.

The treatment of MIBC typically involves neoadjuvant chemotherapy (before surgery) alongside concurrent radiation therapy to shrink the tumor and allow for less extensive surgery.

MIBC is likely to spread quickly and people with MIBC have a poor outlook. You may want to talk with a doctor if you have frequent or persistent symptoms such as blood in your urine, frequent urination, or painful urination.