Breast Cancer Awareness Month was created in part to promote early detection of the disease. Among other objectives, the mission is to educate and encourage testing for those at risk. Understanding what may potentially be a symptom of breast cancer better allows at-risk patients to seek help early on and, if diagnosed, increase their odds of successful treatment.

Patients can benefit from learning about the stages of breast cancer and how they affect the body. Depending on the stage and whether or not the cancer is an invasive form, patients may not experience any symptoms at all prior to a diagnosis. That is why women are advised to start annual mammograms by age 40 to 44 and potentially earlier if there is a family history.¹

Though starting mammograms as early as their health care professional advises remains the best way for patients to detect breast cancer early, understanding symptoms throughout each stage remains extremely beneficial. How is breast cancer staged, and how do symptoms differ throughout?

What Are the Stages of Breast Cancer?

Traditionally, staging in breast cancer goes from stage 0 (non-invasive breast cancers that have not spread to any tissue) up to stage 4. The higher the number, the further the cancer has spread.² Within these stages are designations A and B – an earlier letter is indicative of less severe progression.

These stages are determined by a number of factors including what is known as TNM staging. T refers to the tumor, specifically whether there is evidence of a primary tumor and how large the tumor is. This scale starts at TX (where the tumor cannot be assessed) and T0 (no evidence of a tumor). From there, the scale increases by how large the tumor is from T1 (tumor is 2 cm across) to T3 (tumor is over 5 cm across). After that is T4, in which a tumor is growing into the wall of the chest or skin. N refers to whether cancer has spread to the lymph nodes. This scale goes from N0 to N3, depending on how many lymph nodes the cancer has spread to and if it has spread to specific ones. M refers to metastasis, or whether the cancer has spread to distant organs of the body.

Stage 1 Breast Cancer

Stage 1 breast cancer is the earliest form of invasive breast cancer – at this stage, cancer cells are contained but still affect breast tissue. Patients may have a tumor up to 2 cm across that has not spread to lymph nodes, a tumor under 2 cm with small clusters of cancer cells in the lymph nodes, or cancer cells in lymph nodes with no tumor in the breast.⁴

In this stage, it is still possible to not experience symptoms prior to diagnosis. However, there are still signs to look for that, while they are not surefire indicators of breast cancer, warrant a visit with a health care professional. These include:⁵

A lump that does not go away after a period
Hard lump with irregular edges
Changes to the shape of the nipple
Nipple discharge that is clear or red, brown, or yellow in color
Unexplained redness, swelling, and itchiness around the breast

Detecting breast cancer at this stage is incredibly important for a patient’s survival. Between 2012 and 2018, the 5-year survival rate for patients with localized invasive breast cancer was 99%.⁶

Stage 2 Breast Cancer

In stage 2 breast cancer, the tumor has grown from stage 1 and/or has seen the cancer spread to nearby lymph nodes.⁴ Stage IIA may feature no tumor or a tumor in the breast up to 2 cm with cancer spreading to lymph nodes under the arm, or a tumor ranging from 2 to 5 cm where cancer has not spread to lymph nodes. Stage IIB may be a tumor from 2 to 5 cm with cancer spread to nearby lymph nodes or a tumor over 5 cm across but the cancer has not yet spread to lymph nodes.

As cancer at this stage either has not spread to lymph nodes or has not spread to distant nodes, patients who experience symptoms at this stage are likely facing those similar to that of stage 1.

Stage 3 Breast Cancer

There are three subcategories to stage 3 breast cancer. With stage IIIA, either the cancer has spread to 4 to 9 lymph nodes or the tumor is over 5 cm and has spread to 1 to 3 lymph nodes.⁴ In stage IIIB, the cancer has spread to the chest wall. Here, it may have spread to the skin or even broken through to create an ulcer or wound. This may also be the case in stage IIIC, or the cancer has spread to at least 10 lymph nodes under the arm or to lymph nodes near the collarbone.

At stage 3, other symptoms may appear depending on where the cancer has spread. If it has spread to the skin, patients may experience a new lump, additional redness and swelling, and possible ulcerations.

Stage 4 Breast Cancer

Stage 4 breast cancer is also known as metastatic breast cancer. Here, the cancer has spread to other lymph nodes and distant parts of the body, potentially including organs. The lungs, liver, bones, and brain may be affected at this point.⁷

The effects of metastasized breast cancer may include not only existing breast cancer symptoms that can start at earlier stages, but also symptoms that may affect the parts of the body where the cancer has spread. If the cancer has metastasized to the lungs, patients may experience chest pains or a chronic cough. Metastasis to the liver could cause jaundice, nausea, and abdominal pain. Cancer that has spread to the bone can cause additional swelling and susceptibility to breaks. If it has spread to the brain, patients could potentially experience seizures, headaches, and even behavioral changes.

At stage 4, patients with breast cancer may also experience symptoms not necessarily specific to the affected organs, such as fatigue and unexplained weight loss. Breast cancer classified as distant (spread to other areas of the body) has a 5-year survival rate of just 30%.⁶

Non-invasive (Stage 0) Breast Cancer

A non-invasive stage 0 breast cancer is known as a carcinoma in situ, in which abnormal cells have not reached tissue or become invasive. This can include ductal carcinoma in situ (DCIS), where the abnormal cells form inside the milk duct of the breast.³

DCIS is most often found via mammogram, as it is rare to experience symptoms in this form of breast cancer that has not yet made it to breast tissue. However, it has at times caused symptoms that include a breast lump and bloody discharge from the nipple.

Discuss Breast Cancer Risk With Patients

These symptoms and the severity only further underscore the importance of testing and early detection for patient health and survival. Discussing breast cancer risk and when to begin yearly mammograms may help patients receive a diagnosis at a time when the condition is significantly more treatable.

This article originally appeared on Cancer Therapy Advisor.

References

1. American Cancer Society guidelines for early detection of cancer. American Cancer Society. https://www.cancer.org/cancer/screening/american-cancer-society-guidelines-for-the-early-detection-of-cancer.html. Updated February 24, 2023. Accessed September 11, 2023.

2. Breast cancer stages. American Cancer Society. https://www.cancer.org/cancer/types/breast-cancer/understanding-a-breast-cancer-diagnosis/stages-of-breast-cancer.html. Updated November 8, 2021. Accessed September 11, 2023.

3. Ductal carcinoma in situ (DCIS) – symptoms and causes. https://www.mayoclinic.org/diseases-conditions/dcis/symptoms-causes/syc-20371889. Updated May 18, 2022. Accessed September 11, 2023.

4. Stages of breast cancer. Memorial Sloan Kettering Cancer Center. https://www.mskcc.org/cancer-care/types/breast/diagnosis/stages-breast. Accessed September 12, 2023.

5. Pietrangelo A. What are the early signs and symptoms of breast cancer? Healthline. https://www.healthline.com/health/breast-cancer/warning-signs. Updated January 6, 2022. Accessed September 12, 2023.

6. Survival rates for breast cancer. American Cancer Society. https://www.cancer.org/cancer/types/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-survival-rates.html. Updated March 1, 2023. Accessed September 12, 2023.

7. Metastatic breast cancer: what is it, symptoms, and more. National Breast Cancer Foundation. https://www.nationalbreastcancer.org/metastatic-breast-cancer/. Updated June 2023. Accessed September 12, 2023.

Breast Cancer Symptoms By Stage (1-4)