HER2-negative breast cancers, in contrast, have normal levels of the HER2 protein. This type of cancer accounts for around 70% of all breast cancer cases.

This article highlights the possible symptoms of HER2-negative breast cancer, including signs of cancer cells spreading throughout the body.

Frequent Symptoms

The symptoms of HER2-negative breast cancer are similar to that of HER-2 positive breast cancer.

Breast Lump

The most common first symptom of breast cancer is a new breast lump.

A breast cancer lump is classically firm, painless, irregularly shaped, and fixed to one spot within breast tissue, including the armpit area. It can be located near the surface of the breast or felt deeper inside.

Breast cancer lumps can also be soft, round, and tender to the touch. Due to the variation, it’s essential to get any breast lump evaluated by a healthcare provider. While it is natural to be very concerned if you (or a loved one) feel a breast lump, many are benign (noncancerous).

Other Symptoms

Besides a breast lump, other symptoms of HER2-negative breast cancer may include:

Breast swelling, thickening, or pain Dimpling of the skin on your breast Other skin changes of your breast or nipple, such as flaking, redness, pitting, open sores, and rash Nipple pain or clear or bloody discharge from the nipple Nipple turning or pulling inward Swelling of the lymph nodes (bean-shaped structures) in your armpit or collarbone area Unusual fatigue or unintended weight loss

Symptoms of Metastasis

A critical difference between HER2-negative and HER2-positive breast cancer is that HER2-positive breast cancer tends to grow and metastasize (spread to other parts of the body) faster.

If left untreated, HER2-negative breast cancer will also invade nearby lymph nodes, which serve as avenues for spreading to other parts of the body.

After the lymph nodes, common sites of breast cancer metastasis and corresponding symptoms include:

Bones: Joint and bone pain, broken bone (fracture), impaired mobility Liver: Abdominal bloating and pain, jaundice (yellowing of the skin and white part of the eyes), loss of appetite, nausea Lungs: Difficulty breathing, dry cough, hemoptysis (coughing up blood) Brain: Severe headaches, confusion, weakness, seizure, blurry or double vision

Rare Symptoms

HER2-negative breast cancers (and other types of breast cancer) uncommonly spread to the bladder, thyroid, heart, spleen, and adrenal gland. If they do, they may cause these symptoms:

Bladder: Visible blood in the urine (hematuria) and lower abdominal pain Thyroid: New or enlarging thyroid nodule, neck swelling or discomfort Heart: Shortness of breath, heart arrhythmias, fatigue, and fever Spleen (very rare): Upper-left-sided abdominal pain or a growth found incidentally on an imaging test

Complications

Breast cancer treatment aims to suppress the growth and spread of breast cancer cells and prevent the disease from returning.

The primary treatment methods for HER2-negative breast cancer include surgery, radiation, chemotherapy, and hormone therapy.

Complications from treatment vary depending on the method used but may include one or more of the following:

Surgery: Tenderness or swelling, blood collection in the wound (hematoma), nerve damage, lymphedema (painful swelling as a result of impaired lymph drainage), scarring Radiation: Skin changes, burning pain, fatigue Chemotherapy: Hair loss, mouth sores, loss of appetite, nausea, diarrhea, nerve damage Hormone therapy: Hot flashes, vaginal dryness

When to See a Healthcare Provider

Breast size, shape, and feel vary from person to person. These characteristics can also change with age, menstruation, pregnancy, breastfeeding, certain medications, and weight changes.

See a healthcare provider if you experience any breast signs or symptoms that worry you, especially if you feel a new lump or mass or notice any nipple changes or discharge. This is recommended for people of any sex. While breast cancer happens less often in males than in females, it does occur.

Some people with breast cancer experience no symptoms, which is why screening is essential for some populations. Screening is intended for people with no symptoms of breast cancer and is not used when seeking a diagnosis.

The American Cancer Society recommends that all women at average risk for breast cancer get a yearly mammogram at age 45. Women can begin screening at age 40 if they choose.

People who are transgender or intersex should talk to a healthcare provider to see if breast cancer screening is recommended for them. Screening is not recommended for men at average risk.

Average risk for breast cancer means the following is not present:

A personal or strong family history of breast cancer A genetic mutation (change in the DNA) that increases breast cancer risk (e. g. , BRCA gene) A history of radiation to the chest before the age of 30

Summary

HER2 is a protein typically found on the surface of breast cells. HER2-positive breast cancers have higher than normal levels of HER2, whereas HER2-negative breast cancers do not.

HER2-negative breast cancer causes symptoms (if present) like other kinds of breast cancer. The most common first symptom is a firm, painless breast lump. If not treated, HER2-negative breast cancer can spread to other body parts, typically the liver, lungs, bones, or brain.

A Word From Verywell

If you are worried about developing breast cancer, know that early detection, when more treatment options are available, is crucial. Also, while some factors that increase your risk for breast cancer, like age or genetic makeup, are out of your control, others are not.

When minimizing your risk for breast cancer, focus your efforts on living a healthy lifestyle. Behaviors like maintaining a healthy weight, engaging in regular physical activity, and avoiding or limiting alcohol intake can all lower your chances of getting breast cancer.