Diagnosis & Staging

I have a lump. Does this mean I have breast cancer?

Not always. Many tumors are not cancerous. However, it is important to see your doctor if you find a lump so cancer can be ruled out.

What kinds of breast cancer are there?

There are many kinds of breast cancer and most fall into two main categories:

  1. In situ breast cancers, or noninvasive breast cancers, where the cancer is only in the breast ducts (milk tubes) and lobules (milk-producing glands). This is considered ‘early stage.’
  2. Invasive breast cancers, or infiltrating breast cancers, which start in the breast ducts or lobules but then quickly spread into surrounding breast tissue and other organs.

Which are the most common types of breast cancer?


Invasive (or infiltrating) ductal carcinoma (DC) is the most common breast cancer, with more than 230,000 cases diagnosed in the U.S. in 2015. DC starts in the milk duct of the breast but can spread to other parts of the body.


Another type of breast cancer, called lobular carcinoma (LC), is the second most common breast cancer. It starts out in the lobules and can also quickly spread. LC is harder to detect on a mammogram than DC.


Inflammatory breast cancer (IBC) accounts for one percent to three percent of all breast cancers and is the hardest to treat. In most women, it makes the skin of the breast look red and feel warm or itchy. It is often mistaken for a common breast infection called mastitis. In 30 percent of women who have IBC, their cancer has already spread by the time they are diagnosed.

How is breast cancer found?

There is more than one way to detect breast cancer, and your own self-exams can play an important role.

  • Do regular self-exams to check your breasts for any changes.
  • Early breast cancers are usually detected by an X-ray of the breast called a mammogram. Ask your doctor how often you need a mammogram.
  • Not all mammograms can catch breast cancer, so sometimes doctors use other tools such as an ultrasound to check for cancer if you are having symptoms.

How is breast cancer diagnosed?

The only way to tell for sure if you have breast cancer is to have a biopsy. A biopsy is a procedure that removes a tissue sample of the suspicious area. There are several kinds of biopsies your doctor can choose from, depending on the location and size of your tumor.


  • Uses a thin, hollow needle attached to a syringe to withdraw tissue from a suspicious area
  • Numbing medicine is not always necessary
  • The easiest biopsy to have but often requires a second biopsy if there is no clear diagnosis


  • Uses a bigger needle than the one used in a fine needle aspiration (FNA)
  • Local anesthesia is used
  • More likely than an FNA to provide a clear diagnosis, although it may still miss some cancers


  • A hollow probe is inserted into the abnormal breast tissue and several samples are taken
  • The skin is numbed and no stiches are needed
  • This method usually removes more tissue than a regular core needle biopsy


  • The entire mass and surrounding normal-appearing tissue is removed and examined under a microscope (excisional biopsy))
  • If the mass is too large to be removed easily, only part of it may be removed (incisional biopsy)
  • Typically performed in a hospital in the outpatient setting, with sedation or general anesthesia
  • It usually requires several stitches and may leave a scar


  • Lymph nodes are typically checked for cancer when the breast tumor is removed

How do I know if my breast cancer has spread?

After you’ve had a biopsy, your doctor will want to check and see if your cancer has spread. A number of tests and procedures can detect, diagnose and determine how far your breast cancer may have spread. The most common include:

  • A physical exam and medical history to check for lumps and suspicious areas, including any changes in the nipples and lymph nodes under your arms
  • Imaging that can show tumors in the breast and body:
    • Mammogram to look for suspicious areas in the breast
    • Ultrasound to look at specific areas of concern found on a mammogram
    • MRI (magnetic resonance imaging) using a magnet, radio waves and a computer to examine suspicious areas found by a mammogram

What is metastatic breast cancer?

Metastatic breast cancer means the cancer has spread beyond the breast to other organs in the body. The most common sites breast cancer spreads to are the bones, lungs, liver or brain. Usually, women find out they have metastatic breast cancer months or years after they have been treated for early breast cancer. When the cancer comes back and spreads to other organs, this is called distant recurrence.

What is hormone-receptor status?

If your cancer is hormone-receptor positive (HR+), it has receptors for hormones. This means that the cancer cells may get signals from certain hormones to grow. Knowing the status helps doctors predict that your cancer will respond to treatment called hormone therapy. Most women with breast cancer have HR+ disease. Women can have different types of HR+ disease including estrogen-receptor positive (ER+) or progesterone-receptor positive (PR+) disease. ER+ cancer cells may get signals from estrogen to grow, while PR+ cancer cells may get signals from progesterone to grow.

What is HER2 status?

Some women have HER2-positive breast cancer. This means that their cancer may be more aggressive. As part of your biopsy, your cancer’s HER2 status will be checked. Knowing if your cancer is HER2-positive will help doctors predict if your cancer will respond to certain targeted therapies.

What is triple-negative breast cancer?

This means your breast cancer is not estrogen-receptor positive (ER+), progesterone-receptor positive (PR+) or HER2-positive.

My doctor assigned my breast cancer a grade. What does this mean?

A breast cancer grade is given during a biopsy and describes how likely the cancer is to spread.

  • Grade 1: The cells in these cancers look most like normal cells under a microscope and do not appear to be growing rapidly.
  • Grade 2: The cells in these cancers are somewhat more abnormal.
  • Grade 3: The cells in these cancers tend to grow and spread more aggressively.

What does staging mean?

Your breast cancer’s stage refers to how far the cancer cells have spread beyond the original tumor. There are two systems for determining your cancer’s stage.

TNM staging: TNM stands for tumor, nodes and metastasis.
This system describes:

  • The size of the original tumor
  • If lymph nodes are involved
  • Whether the cancer has spread (metastasized)
T (tumor size)  0⇔4  A higher T number means the tumor is larger, has spread more widely in nearby tissues, or both
N (nearby lymph nodes)  0⇔3  A higher N number means greater spread of cancer cells to lymph nodes near the breast
M (metastasis)  0⇔1

M0 means a physical exam and imaging studies have not found cancer in lymph nodes away from the breast or in distant organs; M1 means distant spread was found






Overall stage grouping: Once TNM is determined, your cancer will be assigned a stage from 0 to IV to describe how far it’s spread.

Stage 0 Noninvasive cancers The tumor is smaller than one inch
Stage 1 Early-stage cancers The cancer has not spread to the lymph nodes under the arm or beyond the breast
Stage 2 Early-stage cancers The tumor is one to two inches in size, or the cancer has spread to the lymph nodes under the arm
Stage 3 Advanced-stage cancers The cancer is more advanced but still in the breast, surrounding tissues and lymph nodes
Stage 4 Advanced-stage cancers The cancer has spread to distant organs or to lymph nodes outside of the underarm area