Stage 4 breast cancer: diagnosis, treatment, survival

Stage 4 is the most common form of breast cancer . It is also called metastatic breast cancer because the cancer spreads (metastasizes) from the breast to other parts of the body, such as the bones, lungs, brain, or liver. Stage 4 breast cancer is often diagnosed when the cancer recurs , although it can sometimes be detected at the initial diagnosis. Although metastatic breast cancer is incurable, treatment can help control the spread of the cancer and ensure a good quality of life. Some people have survived the disease for a long time .

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Location of metastases

Stage 4 breast cancer is diagnosed when cells from the primary breast tumor migrate to other parts of the body and form one or more secondary tumors .

Breast cancer can metastasize to almost any organ in the body. The location of the metastases may be different, but, as a rule, it has a similar picture depending on the type of cancer .

For instance:

Different types of cancer also metastasize at different times and at different rates . For example, estrogen receptor-positive tumors are usually about 3 centimeters (1.2 inches) in diameter before they begin to metastasize. In contrast, a HER2 positive tumor may be less than 1 centimeter (0.4 inch) before spreading to the lymph nodes and beyond.

For the purposes of classification and treatment, breast cancer that has spread to other parts of the body is still considered breast cancer regardless of its location.

For example, breast cancer that has spread to the lungs cannot be called lung cancer. Rather, it will be considered a metastasis of breast cancer to the lungs . If you look at these cells under a microscope, they are breast cancer cells, not lung cancer cells.

Discussion guide with a breast cancer doctor

Get our printable guide to your next doctor's appointment to help you ask the right questions.


Cancer staging is done to guide treatment and predict the likely outcome or prognosis . The most commonly used staging system for breast cancer, and most other cancers, is called the TNM Cancer Classification . In the TNM staging system:

The letters are followed by numbers that indicate the size of the tumor (for example, T1 for a small tumor and T3 for a larger tumor) or the degree of malignancy (N0 means no lymph nodes are affected and N4 means 10 or more nodes affected lymphatic nodes).

Regarding the "M" classification, it can be M0 (no metastasis) or M1 (metastasis). There are no gaps. Therefore, it can refer to the T or N classification and still be considered stage 4 if metastasis is confirmed.

This does not mean that all metastatic breast cancers are treated the same. The diagnosis will also include an evaluation of tumor location, grade, tumor size, hormone receptor status, HER2 status, and many other factors, each of which determines the final course of treatment.

Watch out

The overall goal of stage 4 cancer treatment is to improve the quality of life and life expectancy of patients with metastatic disease. Each case will be treated differently depending on the characteristics of the disease and the intended treatment goals.

Treatment can vary from person to person. Most treatment methods aim to reduce the tumor burden and stabilize the disease. In general, treatment of stage 4 cancer, although it can prolong life in a significant number of patients, is considered palliative because only a minority of treated patients are cured of the disease .

Systemic therapy

For those who choose to continue treatment, systemic therapies (those that distribute treatment throughout the body) are often used. This includes:

A combination of therapies can be used, either together or in stages.

Staging treatment involves using the drug until the side effects become unbearable or the cancer begins to grow again. If this happens, the first-line drug will be replaced by the second-line drug, and so on.

Choose a drug

The choice of systemic therapy is highly dependent on hormone receptor status (a measure of whether estrogen or progesterone hormones affect tumor growth) and / or HER2 status (whether a particular gene affects tumor growth ).

A positive state means that receptors for these substances have been found on cancer cells, while a negative state means that no receptors have been found. To determine this, pathologists use cancer cells obtained by biopsy or surgery.

Based on these evaluations, the oncologist will generally recommend the following treatments:

  • Hormone receptor positive cancers are often treated with hormone therapy such as tamoxifen or an aromatase inhibitor . It can be combined with a targeted drug such as Afinitor (everolimus), Ibrans (palbociclib), Kiscali (ribociclib), or Vercentio (abemacyclib).
  • Hormone receptor-negative cancers are usually treated with chemotherapy.
  • For HER2-positive cancers , the target drug Herceptin may help when used in combination with chemotherapy, hormone therapy, or other HER2 drugs .
  • HER2 negative cancers are usually treated with chemotherapy. Hormone therapy may be added if the cancer is hormone receptor positive. The targeted drug Linparza (olaparib) is sometimes given after chemotherapy for people with mutations in the BRCA1 or BRCA2 genes .

Radiation and surgery

In addition to systemic therapy, radiation therapy and surgery can be helpful in certain circumstances. In particular, with radiation, the goal can be therapeutic (slowing the progression of the disease) or palliative (providing comfort by shrinking the tumor).

Examples of how these treatments are used include:

Radiation can also shrink tumors that have penetrated the skin and caused an open wound in the chest or chest .

Since existing treatments are unlikely to cure metastatic breast cancer, you can participate in clinical trials to test new treatments if you are in good health.


The five-year survival rate for stage 4 breast cancer is 27 percent, according to an observation from the National Cancer Institute. This means that 27 percent of women will live at least five years. Some will live much longer, others less. The average life expectancy is three years.

Sad as it may sound, the figures do not distinguish between the number of women who choose to undergo treatment and those who do not. Therefore, you should not assume that having a stage 4 breast means that you have three to five years to live. Some women will live more than 10 years .

Several factors are known to affect survival, including:

  • Age
  • Health at the time of diagnosis
  • Cancer stage at diagnosis
  • Location and extent of metastases
  • HER2 or hormone receptor status
  • Cancer recurrence
  • Previously used treatments


While the goal of early cancer treatment is to eradicate the cancer and maintain remission , the goals associated with stage 4 cancer are different. The main goal is to prevent the spread of cancer, which requires constant monitoring.

The most widely used imaging technique known as positron emission tomography / computed tomography (PET / CT) . It includes PET technology , which monitors metabolic changes in the body, and CT technology , which uses X-rays to create cross-sectional images of tissue (to measure tumor size and disease progression).

Other techniques, such as magnetic resonance imaging (MRI) and dual-energy x-ray absorptiometry (DEXA) , can be used to monitor certain bone or soft tissue cancers, respectively.

Serial tumor blood markers are also used to monitor disease status. These are blood tests that look for substances called tumor markers that increase as the cancer spreads or progresses. Examples include the tumor markers CA 15-3 and CA 27-29, which are elevated in more than 70% of metastatic breast cancers.

Progressive disease

Although systemic treatment can keep cancer stable for months or years, there are times when it becomes unstable and begins to progress. When this happens, changing treatment can often stabilize the cancer.

Generally speaking, doctors start with hormone therapy (if the hormone receptor is positive) or targeted therapy (if it is HER2 positive), changing the individual agents if one begins to fail.

If they no longer work, chemotherapy will be used. However, each time the cancer progresses during chemotherapy, the chance that the new drug will work gradually decreases. It is at this stage that palliative care should be considered.

Front facing

When you are diagnosed with stage 4 breast cancer, it is natural. This can make you feel like you are not in control of your health or your future. Also, some people may drop out or assume they have metastatic cancer because they "left it too late."

It's important to isolate yourself from these negative emotions and accept those who can give you sincere support. These include loved ones, support groups, and your cancer team. If you cannot cope, ask for referrals to a therapist who will advise you or to a psychiatrist who will prescribe treatment.

That said, there are women who experience positive emotional growth after being diagnosed with stage 4 breast cancer. It is not uncommon to hear someone say that cancer has helped prioritize their lives, allowing them to do what really matters and connect with them. people on a deeper and deeper level.

Whatever your experience, don't go it alone. Seek support and work with your healthcare team as a full partner in your care.

Get the word of drug information

It is important to remember that these survival statistics are based on large numbers of women, each with her own characteristics. Also, as new and more effective drugs are developed and released, the current five-year survival rate may be very different from what is released five years later.

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