People who have found a lump, have recently received a breast cancer diagnosis, or know someone with breast cancer may wonder how fast it can grow or spread over the course of a year.

Breast cancer is the most common cancer diagnosis among women in the United States.

It is difficult to estimate how a person’s breast cancer will change over the course of a year. Different types of breast cancer grow at different rates, and many factors affect its growth and chances of spreading.

This article looks at how quickly breast cancer might spread, common ways that breast cancer can progress, and the long-term outlook for the condition.

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It is hard to say exactly how quickly breast cancer can grow, including the timeframe, as the disease affects each person differently. In some cases, people may have breast cancer for years and not know.

Although it is difficult to assess the progress of cancer over the course of 1 year, the American Cancer Society provides estimates of the 5-year relative survival rates for people at different stages of breast cancer.

The 5-year relative survival rate predicts how likely a person with breast cancer is to live for 5 years compared with people who do not have that diagnosis.

Breast cancer stage5-year relative survival rate
stage 1almost 100%
stage 293%
stage 372%
stage 422%

These figures are population estimates. Each person’s individual survival rate depends on a wide range of factors.

There is also an earlier stage of breast cancer, known as ductal carcinoma in situ, or stage 0. This is when cells in the breast ducts begin to turn cancerous but have not spread beyond the ducts.

Breast cancer growth and its chances of spreading depend on the following:

Type of breast cancer

Breast cancer can be invasive or noninvasive:

  • Ductal carcinoma in situ will not spread beyond the ducts.
  • Invasive breast cancer can spread to the surrounding connective tissue, the lymph nodes, and other areas of the body.

Grade (1–3)

A doctor will grade breast cancer (1–3) based on how much the cancer cells look like normal breast cells:

  • Grade 1 is a slower-growing cancer.
  • Grade 3 is a faster-growing cancer.

A higher grade means that a cancer is more likely to grow faster and spread to other areas of the breast or body.

Stage (0–4)

Healthcare professionals describe the extent of breast cancer progression in stages. This information is incredibly important when making decisions regarding treatment.

The stages of breast cancer are as follows:

  • Stage 0: Doctors consider breast cancer at this stage noninvasive, and it is only present in the ducts or the lobules. Ductal carcinoma in situ is a form of stage 0 breast cancer.
  • Stage 1: Breast cancer at this stage is invasive, but it remains small and near the primary site. Stage 1A involves tumors that are 2 centimeters or smaller and have not reached the lymph nodes. At stage 1B, the cancer has reached the lymph nodes.
  • Stage 2: Stage 2 breast cancer is invasive; tumors may be larger than in stage 1, and the cancer may have spread to the lymph nodes.
  • Stage 3: Stage 3 breast cancer is invasive, tumors may be larger, and cancer has spread to the lymph nodes, possibly to several. Breast cancer at this stage has not spread to other organs.
  • Stage 4: Breast cancer has developed in other areas, often in the bones, lungs, brain, or liver. Doctors still consider this stage treatable but not curable. Treatment at this stage focuses on controlling the cancer and preventing it from spreading any further.

Cancer that has already spread to other areas of the body, or stage 4 cancer, is more likely to spread further.

Personal factors

Growth or spread within a year will often depend on personal factors, including:

  • age at diagnosis
  • hormone status, such as being pre- or postmenopausal
  • family history of breast cancer
  • exposure to alcohol, cigarettes, or pollution
  • previous history of cancer

Response to treatment

A doctor may also take how a person responds to previous or current treatment into account when working out the likely change or progression of cancer.

Breast cancer occurs when normal cells mutate and multiply faster than usual. The uncontrolled multiplication of cancer cells creates tumors within the breast tissue.

In most cases, breast cancer initially develops in either the milk ducts or the lobules, which are the glands that produce milk, before expanding into the breast tissue.

Breast cancer that develops in ducts or lobules can spread to the connective tissue. From there, it can spread to the surrounding lymph nodes and then the bloodstream.

Certain types of breast cancer, such as triple-negative breast cancer and HER2-positive breast cancer, grow at faster rates.

People with breast cancer may experience a range of symptoms, but not all people will experience the same symptoms. Also, according to the Centers for Disease Control and Prevention (CDC), some people with breast cancer experience no symptoms at all.

Some signs and symptoms of breast cancer include:

  • a lump or mass in the breast tissue
  • pain, swelling, or redness on any part of the breast
  • dimpling of the skin covering the breast
  • unusual nipple discharge
  • flaking skin on or near the nipple
  • change in the shape or size of the breast

Diagnosing breast cancer begins with screening for early signs. Procedures may include breast examinations and mammograms.

If a healthcare professional finds early signs of breast cancer or suspects that a person may have breast cancer, they will likely order additional tests. These may include:

  • breast examination
  • mammogram
  • ultrasound
  • MRI
  • biopsy

Breast cancer treatment plans depend on the type and stage of the cancer, as well as a person’s overall health status and their personal preferences.

Treatments for breast cancers are often both local and systemic.

Local treatments

These aim to remove or destroy cancer in a particular area of the body. Local treatments aim to destroy or remove as many cancer cells as possible without damaging healthy tissue.

Examples of local treatments for breast cancer include:

Systemic treatments

These can effectively destroy cancer throughout the body. However, systemic treatments can negatively affect healthy cells and cause uncomfortable side effects.

Examples of systemic treatments include:

Factors such as age, cancer status, and a person’s overall health all affect how quickly cancer spreads.

Breast cancer detected at early stages (0–1) is very treatable. At later stages, breast cancer treatment is more aggressive, as it aims to destroy the cancer and prevent further growth to reduce the risk of recurrence.

Stage 4 breast cancer is not curable, and treatment aims to shrink the cancer when possible and help prevent it from growing or spreading any further. While a person with stage 4 cancer may never be cancer free, controlling the cancer is still considered a positive outcome in this situation.

The Breast Cancer Healthline app provides people with access to an online breast cancer community where users can connect with others and gain advice and support through group discussions.

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