Stage 3 cancer: definition, diagnosis, treatment, prognosis


Saying that you or someone you love has stage 3 cancer can be intimidating. Stage 3 cancers are more advanced; Tumors are usually more extensive and can spread (metastasize) beyond stage 1 or 2, but there are effective treatments for many types of stage 3 cancers.

Understanding the stages of cancer, the so-called TNM scale, is vital for anyone who has been diagnosed with cancer. Stage affects patient survival, treatment options, and the potential for remission.

On the TMN scale, stage 3 cancer is quite advanced. The tumor in question usually grows and the affected tissue can invade other organs (metastasize). It is also called locally advanced cancer or regional cancer.

Treatment for stage 3 cancers depends on the affected organ, but they are generally larger and more difficult to treat than stage 1 or stage 2 cancers. The prognosis of stage 3 cancer depends on many other factors, including its location, response to the treatment and the health and age of the patient.

Stage 3 cancers require specialized care, and likely to a great extent. Although some stage 3 cancers are treatable , called remission of the cancer, they are more likely to return when they are gone.

Doctors use cancer stages to compare patients with similar diagnoses, to make it easier to study the effectiveness of treatments, to track the progression of cancer in a person, and a way to estimate survival for specific cancers. Let's take a look at how these stages are defined and what they mean for the treatment and prognosis of the patient.

Learn about medicine / Teresa Chiechi


When evaluating the stage of a patient's cancer, doctors use a classification system developed by the American Joint Committee on Cancer. It consists of three parts and is called the TNM system. Although the actual breakdown of letters and numbers differs from cancer to cancer, they have the same general structure :

  • T in the system defines the tumor itself. Doctors will look at the size of the tumor and how far (within surrounding tissue or organs) it has spread. The T score ranges from 0 to 4. The larger the tumor and the more it has spread, the worse the patient's prognosis.
  • N describes both the extent of lymph node involvement and the number of lymph nodes in the tumor area. The N value of the tumor ranges from 0 to 3 depending on how far it has spread.
  • M stands for metastasis – the spread of cancer cells to other hard organs. There are only two M stages: 0 or 1 for no or yes, respectively. Metastatic cancers are more difficult to treat.

Not all cancers use the TNM system for staging:

Stage 3 diagnostic criteria

Although we speak of stage 3 cancer as a monstrous phenomenon, its diagnosis varies greatly depending on the type of cancer. Generally, a diagnosis of stage 3 cancer requires one or more of three characteristics:

  • Growth of the tumor beyond a certain size (usually measured in centimeters)
  • It spreads to a specific set of nearby lymph nodes (eg, axillary lymph nodes in breast cancer)
  • Spread of the tumor to nearby structures (such as the chest wall in breast cancer )

Once diagnosed, the stage of the cancer never changes. Even if the doctor diagnoses the cancer again or repeats it (marked with the letter r), the doctor keeps the original diagnosis.

The doctor will add the new diagnosis to the initial stage and highlight it with letters, for example, c for clinical, p for pathological (after surgery) or after treatment (y) .

Some stage 3 cancers are subdivided to provide a more accurate classification. These substeps will differ depending on the specific cancerous organ. For example, stage 3 breast cancer is divided into three subcategories :

3A :

  • The tumor is less than 5 centimeters (cm) but has spread to 4-9 nodes.
  • The tumor is larger than 5 cm and has spread to 1 to 9 nodes.

3B : A tumor of any size, but that has invaded the chest wall or breast skin and is swollen, inflamed, or has sores. It could also capture up to 9 nearby nodes.

3C : The tumor can be any size, but has spread to: 10 or more lymph nodes, nodes near the clavicle, or lymph nodes near the armpits and breastbone.

Doctors also diagnose stage 3C breast cancers as feasible or inoperable, but that doesn't mean they won't respond to treatment. It simply means that surgery will not be able to remove the entire tumor.

Other factors

There are a few other things that help doctors determine the stage of the cancer:

  • Cell type : Even if cancer occurs in an organ, it can act differently depending on which cell is malignant. Each of our organs has many types of cells with different functions, each of which can become cancerous. The actual type of cells that have grown into a tumor can influence how the cancer works and responds to treatment. For example, cancer of the esophagus caused by cells of the mucous glands responds differently to treatment than cancer of the esophagus .
  • Location of the tumor : The location of the tumor in the organ can affect the stage of the cancer. For example, the stage of esophageal cancer depends in part on the location of the tumor in the esophagus .
  • Tumor markers in blood : For some cancers, doctors can look for certain cellular materials, usually proteins, in the blood. These markers can help them determine the stage of the tumor. For example, the stage of prostate cancer depends on the level in the blood of a protein called prostate specific antigen, PSA. Higher PSA levels may indicate a higher stage of the cancer .
  • Tumor genetics : Genes and mutations in a tumor affect the stage of the cancer. When cells in the body become cancerous, their genes change rapidly to acquire new characteristics .


Because cancer is so complex, many tests and procedures are used to identify it. They differ according to the type of tumor and not all are suitable for all types of cancer. Here are some standard tests and what they usually look for:

  • Visual tests : Doctors use imaging techniques such as X-rays, computed tomography (CT) , magnetic resonance imaging, ultrasound, and positron emission tomography (PET) to look inside the body without cutting into the patient. These images give the doctor a better idea of the size and composition of the tumor. They can also tell you about other affected organs and blood flow.
  • Endoscopy : Endoscopy , in which a doctor inserts a small tube or wire into the body to view internal organs with a small camera, includes tests such as colonoscopy, bronchoscopy, and laparoscopy. Doctors will use the tube to take pictures and even sample any unusual findings.
  • Biopsy : During a biopsy, a doctor takes a tissue sample from a potential tumor and then examines it under a microscope. These tissue samples can be taken from anywhere on the body, including the skin, bone marrow, or breast. The biopsy may be a vacuum or fine needle biopsy (FNA) .
  • Laboratory tests : Doctors can learn a lot by testing your blood, other body fluids, and tissue samples (biopsies). The tests can look for tumor markers that give them more information about your cancer. They can run gene tests for cancer to find out more about it and perform blood counts to monitor the patient's health .

Watch out

Surgery is often a doctor's first line of defense against a tumor. Surgical resection is the preferred treatment for most solid cancers.

In some cases, stage 3C cancers undergo chemotherapy to shrink the tumor and then surgically remove it.

These treatments include:

  • Chemotherapy uses powerful drugs to kill cancer cells. It treats cancer and can also relieve cancer symptoms. Chemotherapy also destroys fast-growing cells in the body, such as those that line the mouth, intestines, and hair follicles. This causes many side effects, including hair loss .
  • Radiation therapy uses radiation to kill cancer cells. Radiation is energy that can damage cells, which is why doctors use it to weaken cancer cells. They usually target this treatment to a specific area of the body where the cancer is found, but results can take days or weeks .
  • Hormone therapy , also known as endocrine therapy, only applies to certain forms of tumors, those that require hormones to grow, usually prostate and breast cancers. By depriving cancer cells of hormones, this treatment can cure cancer and relieve its symptoms. Because these treatments target the body's hormones, they have different side effects based on gender .
  • Targeted therapy , a form of personalized medicine, is specifically designed against cancer based on its genetics. These treatments can help slow and stop the growth and spread of cancer cells by acting on the changes that allow these cells to get out of control. Targeted therapy can include drugs or antibodies made against specialized proteins in the tumor .
  • Immunotherapy uses the body's immune system against cancer. It may be surprising, but there are many mechanisms in the body that find and destroy potentially cancer cells on a daily basis. These treatments help support the body's immune system to fight cancer.

The treatments an oncologist uses to diagnose cancer depend largely on the type of cancer , the extent of its spread, and many other criteria. For example, let's look at a general approach to treating a stage 3 diagnosis of three common types of cancer:

  • Breast cancer : Doctors usually treat stage 3 breast cancer with chemotherapy to shrink the tumor before surgery. After surgery, radiation therapy and hormone therapy can be used to kill any remaining cancer cells .
  • Colorectal Cancer : The first step in treating stage 3 colorectal cancer is usually surgery to remove cancerous parts of the colon and associated lymph nodes. Irradiation of a tumor that could not be completely removed can be used .
  • Melanoma : Treatment for stage 3 melanoma begins with surgery, usually extensive surgery and the removal of local lymph nodes. Targeted and immune therapies can reduce the risk of tumors coming back, potentially in conjunction with radiation or chemotherapy, especially if the lymph node infiltration is severe .

When the signs and symptoms of cancer disappear, the patient is declared successfully cured and is in remission. Stage 3 cancer remission rates , like survival rates, depend on the type of cancer and available treatments.

Stage 3 cancer treatments can be complex and involve many doctors, nurses, and centers. One thing that can help patients is the hospice team. These specialized doctors, nurses, and social workers work with critically ill patients to alleviate symptoms and side effects of treatment. They work to improve the stress levels of patients. Palliative care can help regardless of the stage of the cancer .


Heidi Sayn / EyeEm

The prognosis for stage 3 cancer can vary based on the type of cancer, its grade, genetics, and others. Patient characteristics can also affect prognosis. Age, general health, whether you are an active or ex-smoker, and your functional status, a way of assessing a patient's ability to perform daily tasks, affect prognosis and survival .

Doctors use survival rates to estimate the probability that a person with a certain diagnosis will be alive in five years. Cancer survival rate is the proportion of people with a specific diagnosis who did not die from that cancer. The relative survival rate estimates how many of the people diagnosed did not die of anything (cancer or otherwise) during that time .

Survival is usually measured by the 5-year survival rate (the number in 100 people who are expected to live at least five years), although you can also see the 1-year, 2-year, and 10-year survival rates. …

You can find cancer survival rates in the National Cancer Institute's (SEER) Surveillance, Epidemiology, and Results database, which has been collecting and publishing cancer statistics from 19 states since 1973 .

The SEER database does not use the TNM staging system. Cancer registries like SEER typically take a three-step approach:

  • Localized : Cancer cells are found only in the area where they first developed.
  • Regional – The tumor has spread to nearby lymph nodes, tissues, or organs (this usually includes stage 3 cancer).
  • Distant : in which the cancer has spread to distant parts of the body.

Although these definitions make it easier for cancer registries to classify patients, there are limitations to SEER definitions. That is, many stage 2 and 3 cancers meet the SEER definition as "regional," while stage 3C approaches "distant."

Keep this in mind when looking at the 5-year survival rates below – they only give you a rough estimate of life expectancy.

For an overview of survival rates, see these figures below from the SEER NCI database, which tracks cancer incidence and outcomes. The numbers below for the top 10 cancers represent the five-year survival rate (compared to similar people without cancer) for a "regional" diagnosis, based on data from 2010 to 2016 .

The exceptions are lymphoma and leukemia, which doctors diagnose in different ways. The number of non-Hodgkin lymphomas is the survival rate at stage 3 and leukemia is the overall 5-year relative survival rate (at any stage).

"Regional" survival rate for stage 3 cancer
Number Location Survival percentage
1 Female breast) 85.7%
2 Lungs and bronchi 31.7%
3 Prostate 100%
4 Colon and rectum 71.8%
5 Melanoma (skin) 66.2%
6 Bladder 36.5%
7 Non-Hodgkin's lymphoma * 70.5%
Eight Kidney and renal pelvis 70.4%
nine Uterus (endometrium) 69.4%
ten Leukemia* 63.7%
eleven Pancreas 13.3%
12 Thyroid 98.3%

Get the word of drug information

A cancer diagnosis is a life-changing event, especially if advanced cancer is diagnosed. But stage 3 cancer is not a death sentence. Survival rates are constantly improving, and clinicians and researchers are constantly discovering and testing new targeted drugs and immunotherapy drugs.

Related Articles
Foods to Avoid If You Have Dry Mouth From Radiation

Dry mouth (xerostomia) is a common side effect of radiation therapy for people undergoing treatment for head and neck cancer. Read more

Thyroid adenoma: Causes, Treatment, and Diagnosis

The thyroid is a small, butterfly-shaped gland in the front of your throat that produces hormones affecting a number of Read more

NSAIDs and You Thyroid Function

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most frequently taken over-the-counter medications. Due to their systemic or whole body effects, it's Read more

How Doctors Are Failing Thyroid Disease Patients

The thyroid disease community has continually mentioned the lack of support they experience and the difficulty they have navigating the Read more