Managing breast cancer usually takes different approaches due to physical and biological characteristics of the disease, same as age, and the overall wellbeing of the patient.

Whenever a woman is diagnosed with breast cancer, it is important for the doctor or personnel attending to her at the moment to inform her of what stage the cancer is. This is referred to as staging. Staging describes or classifies a cancer based on how much cancer is in the body and where it is when first diagnosed. The stage often includes the size of the tumour, which parts of the organ have cancer, whether the cancer has spread (metastasized) and where it has spread.

Breast cancer is typically labeled in stages from I to IV, with IV being the most serious. Those broad groups are based on a much more detailed system that includes specific information about the tumor and how it affects the rest of the body.

Why Stage Breast Cancer?

It is important to note that staging cancer has it is own reasons, and they include:

• It helps to create a better treatment plan for the patient
• It helps to predict a person’s outlook, the course of the disease or the chance of recovery (i.e. prognosis).
• To predict how well the treatment will work.
• It helps to identify the groups of people to study, and compare during clinical trials.
• Helps you choose a clinical trial if you want to join one.

How Breast Cancers Are Staged?

Just like other forms of solid tumour cancers, doctors use screening exams and tests to stage a cancer. The exams and tests show where the cancer is, and approximately how much cancer is in the body. To stage a cancer, doctors may do a physical exam, blood tests, imaging tests or a biopsy.

Stage Grouping

The TNM description is mostly used to assign an overall stage from 0 to 4 for many types of cancer which includes breast cancer. Stages 1 to 4 are usually given as the Roman numerals I, II, III and IV, therefore the higher the Roman number, the more the cancer had spread. Sometimes these stages are subdivided using the letters A, B and C.

• Stage 0 means there's no cancer, only abnormal cells with the potential to become cancer. This is also called carcinoma in situ.
• Stage I means the cancer is small and only in one area. This is also called early-stage cancer.
• Stage II and III means the cancer is larger and has grown into nearby tissues or lymph nodes.
• Stage IV means the cancer has spread to other parts of your body. It's also called advanced or metastatic cancer.

TNM Staging System

T (TUMOUR): This describes the size of the main (primary) tumour,  describing if the tumour has grown into other parts of the organ with cancer or tissues around the organ. It is usually given as a number from 1 to 4. Higher number means that the tumour is larger, and also grown deeper into the organ or into nearby tissues.

N (LYMPH NODES): This describes whether cancer has spread to lymph nodes around the organ. N0 means the cancer hasn’t spread to any nearby lymph nodes.

M (METASTASIS): This describes whether the cancer has spread to other parts of the body through the blood or lymphatic system.

Sometimes the lowercase letter a, b or c is used to subdivide the tumour, lymph nodes or metastasis categories to make them more specific (for example, T1a). Lowercase “is” is added after T (Tis) to describe a carcinoma in situ.

Types Of TNM Staging

Solid tumour cancers may be given both a clinical and pathologic stage.

Clinical stage is given before treatment. It is based on the results of exams and tests, such as imaging tests, done when the cancer is found (at the time of diagnosis). Doctors often choose a treatment based on the clinical stage. The clinical stage is shown by a lowercase “c” before the letters TNM on some medical reports.

Pathologic stage is based on the results of tests and exams done when the cancer is found and what is learned about the cancer during surgery and when looking at the tissue after it is removed by surgery. It gives more information about the cancer than the clinical stage. The pathologic stage is shown by a lowercase “p” before the letters TNM on a pathology report.

The clinical and pathologic stages of a cancer can be different. For example, during surgery doctors may find cancer in an area that didn’t show up on an imaging test so the pathologic stage may result in a higher stage.

Other Factors In Staging Breast Cancer

Other factors that are used to determine the stage for some types of cancer include:

• Cancer cell type (such as adenocarcinoma or squamous cell carcinoma)
• Grade: This is how cancer cells look under a microscope. Low grade means they look a lot like normal cells. High grade means they look very abnormal. Low-grade cancer cells grow more slowly and are less likely to spread than high-grade.
• Location: Where the tumor is in your body may make it harder to treat.
• Tumor markers: These are things in your blood or urine that are at higher levels when you have certain kinds of cancer.
• Genetics: The DNA of the cancer cells can tell your doctor if it's likely to spread and what treatment may work.

Can Staging Change?

Once an individual is informed about the breast cancer stage, the stage of cancer doesn’t change. If a stage 2 cancer comes back (recurs) after it is treated, it is still stage 2 cancer that has recurred. And if the cancer has spread to a distant part of the body after it is treated, it is still stage 2 breast cancer but it is metastatic.

This is because the treatment options and chances of recovery usually are based on how early the breast cancer is diagnosed. Only in few cases, cancer may be restaged with a new round of tests after treatment or if it comes back.