When a bladder tumor grows, it typically begins in the bladder’s inner lining and spreads outward. If left untreated, cancer cells may grow deeper into the bladder wall and into nearby tissues. Urologists — doctors who specialize in the urinary system — classify bladder cancer by how far and how deeply it has spread.

Bladder cancer that remains confined to the bladder lining is called non-muscle-invasive bladder cancer (NMIBC). If the cancer spreads into the bladder’s muscle wall, it’s called muscle-invasive bladder cancer (MIBC). NMIBC is considered an earlier stage of bladder cancer, while MIBC is more advanced.

Around 70 percent to 75 percent of people diagnosed with bladder cancer have NMIBC. The remaining 25 percent to 30 percent are diagnosed with muscle-invasive disease.

These two forms of bladder cancer differ in how aggressive they are, how they are treated, and what outcomes are expected. In this article, we’ll explain the differences between NMIBC and MIBC.

MIBC Is Later-Stage and High-Grade

A cancer’s stage is a way of describing how far cancer cells have spread from where they first formed. In bladder cancer, staging refers to how deeply the tumor has grown from the inner lining of the bladder into surrounding layers or nearby organs. NMIBC includes early-stage cancers, such as:

• Ta — The tumor is confined to the bladder lining and has not entered the muscle.
• Tis — This is a flat, high-grade tumor known as carcinoma in situ (CIS) that sits on the bladder lining and has not invaded deeper layers.
• T1 — The cancer has spread into the layer beneath the lining but not into the muscle.

Muscle-invasive stages include:

• T2 — The tumors have grown into the muscle layer.
• T3 — Tumors have spread to tissues around the bladder.
• T4 — Tumors have moved to nearby organs in the pelvis, including the prostate, uterus, vagina, or the pelvic or abdominal walls

Bladder tumors are also described by grade, which refers to how abnormal the cancer cells look under a microscope and how likely they are to grow or spread. High-grade bladder cancers grow and spread more aggressively and are more likely to come back after treatment. Low-grade cancers tend to grow slowly and are less likely to spread.

NMIBC is at an earlier stage and may be considered low-grade or high-grade. All muscle-invasive bladder cancer is considered high-grade, meaning it's more likely to spread.

Most NMIBC tumors may be low or high grade, depending on several factors. However, all MIBC tumors are considered high-grade.

NMIBC and MIBC Symptoms Are Similar

The symptoms for NMIBC and MIBC often overlap. Other conditions, like kidney stones or urinary tract infections, can also cause these symptoms. If your healthcare provider suspects you have bladder cancer, they’ll recommend tests to confirm the diagnosis and determine if you have NMIBC or MIBC.

Talk to your healthcare provider if you experience any of the symptoms below:

• Blood in your urine (the most common symptom)
• Frequent or urgent need to pee
• Burning or pain when you urinate
• Pain in your lower belly or back

Read more about potential symptoms of NMIBC.

NMIBC Treatments Include TURBT and BCG Immunotherapy

The first-line treatment for NMIBC is usually transurethral resection of bladder cancer (TURBT). During TURBT, a surgeon removes any visible tumors from the bladder using a thin, tubelike tool inserted through the urethra. They may also take small samples of the bladder muscle for analysis, called a biopsy. The goal is to remove as much of the tumor as possible. After TURBT, most people receive a single dose of chemotherapy (chemo) delivered intravesically (directly into the bladder).

After this, treatment courses vary depending on whether your NMIBC is high- or low-risk. For high-risk NMIBC, bacillus Calmette-Guérin (BCG) immunotherapy is often recommended. BCG is made from a weakened form of the bacteria used in the tuberculosis vaccine. This type of bacteria activates your immune system to attack cancer cells in your bladder.

Some people with NMIBC won’t respond to BCG immunotherapy. The treatment options in this situation are similar to those used for MIBC, described below.

NMIBC is usually treated with TURBT surgery, which spares the bladder. People with muscle-invasive bladder cancer are often advised to have their bladder removed.

MIBC Is Treated With Bladder Removal and Chemotherapy

BCG treatment is not effective for MIBC. TURBT is usually still performed to help determine the stage and grade of the tumor. However, TURBT alone is usually not enough to treat this type of cancer.

Radical cystectomy (surgery to remove the bladder) is the standard treatment for MIBC. In a radical cystectomy, a surgeon removes your bladder and nearby lymph nodes. Depending on your anatomy, they may also remove the prostate and seminal glands or the uterus and fallopian tubes. To replace the function of the bladder, the surgeon creates a urinary diversion, which is an alternate way to store and remove urine from your body.

Treatment guidelines from the American Urological Association recommend chemotherapy before cystectomy, called neoadjuvant chemotherapy, to improve outcomes.

Radical cystectomy is major surgery. Some people may prefer to try a different approach first, or may not be able to have this surgery due to other health conditions. In these cases, your care team may recommend bladder preservation therapy — a combination of maximal TURBT (removing as much of the tumor as possible), chemotherapy, and radiation. This treatment aims to remove as much of the cancer as possible and then destroy any remaining cancer cells using chemo and radiation.

Although bladder preservation is an option, radical cystectomy is generally considered the most effective way to lower the risk of cancer recurrence. Deciding between these treatments is a personal decision that should be made in partnership with your healthcare provider.

NMIBC Has a Better Prognosis Than MIBC

In general, people diagnosed with NMIBC tend to have a better outlook than those with MIBC. Prognosis — or expected outcome — depends on many factors, including the stage and grade of the cancer, how far it has spread, and whether it returns after treatment.

Survival After Diagnosis

According to the National Cancer Institute, the five-year relative survival rate for carcinoma in situ is 97 percent. This means that people with this type of NMIBC are 97 percent as likely to live at least five years after diagnosis as people without bladder cancer.

For localized bladder cancer (when the cancer is only in the bladder), the five-year survival rate is 71 percent. This includes many cases of NMIBC.

For MIBC, the survival rate depends on how far the cancer has spread. The five-year survival rate is about 39 percent if the cancer has spread to nearby lymph nodes or organs (regional disease), and 8 percent if it has spread to distant parts of the body (metastatic disease).

People with NMIBC are more likely to live longer and less likely to experience cancer spreading compared with those who have muscle-invasive cancer.

It’s important to remember that these statistics describe large groups — not individuals. Your outlook may be different depending on your treatment plan, age, overall health, and other personal factors.

Read more about risk factors that affect NMIBC outcomes.

Cancer Progression

“Progression” means that cancer has become more advanced — for example, by growing into deeper layers of tissue or spreading to other parts of the body. The risk of progression is higher with MIBC than with NMIBC. People with MIBC are also more likely to develop metastatic disease, where cancer spreads beyond the bladder to distant parts of the body.

In NMIBC, how the cancer responds to treatment — especially BCG immunotherapy — can affect the risk of progression. Studies show that about 10 percent to 20 percent of people whose cancer responds well to BCG eventually experience progression. But for people whose NMIBC doesn’t respond to BCG, the risk of progression rises to about 66 percent.

Cancer Recurrence

Another important measure of cancer outcome is the rate at which cancer recurs (comes back). In people with MIBC who have had a cystectomy, the rate of recurrence is about 5 percent to 15 percent. Recurrence usually happens in the first two years after surgery, though it can happen up to five years later.

If this type of cancer comes back to the pelvis, the prognosis is typically poor. Even with treatment, the median survival after a recurrence is about four to eight months. This means that 50 percent of people will live less than that, and 50 percent will live longer. There are treatment options that can improve survival and relieve symptoms, including combinations of chemotherapy, radiation, and surgery. Your urology team can explain whether these options are right for you.

In general, more than 50 percent of people diagnosed with NMIBC will have a recurrence within five years of their first tumor removal. However, most recurrences don’t involve cancer spreading to deeper tissue or other areas. The chance of recurrence depends on the stage and grade of the cancer, and how well it responds to treatments like BCG.

Work With Your Doctor To Stay Ahead of Bladder Cancer

Whether you’re newly diagnosed or living with bladder cancer, working closely with your healthcare team is essential. An accurate diagnosis shapes your treatment options and outlook.

Even after treatment, regular follow-up care is important for staying on top of your health. Your doctor can help you set up a schedule for follow-up appointments, tests, and scans to watch for any signs of cancer returning or progressing. By tracking changes early and sticking with a personalized care plan, you and your care team can make informed decisions and take steps to protect your health over time.

Talk With Others Who Understand

On MyBladderCancerTeam, the social network for people with bladder cancer and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with bladder cancer.

Were you diagnosed with non-muscle-invasive bladder cancer or muscle-invasive bladder cancer? Did you discuss prognosis with your doctor? Share your experiences in the comments below, or start a conversation by posting to your Activities page.