Symptoms of HER2+ Metastatic Breast Cancer

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HER2-positive metastatic breast cancer is a type of cancer that starts in the breast and then spreads, or metastasizes, into other areas of the body, such as the lungs, liver, bones, or brain. HER2-positive means the cancer cells have more than a normal amount of HER2 proteins on the outside of the cells. These proteins signal the cells to continue to grow.

This article will review the possible symptoms of HER2-positive metastatic breast cancer. 

Brain Symptoms of HER2+ Metastatic Breast Cancer: A person's head with squiggles (headaches or dizziness), two clocks (vision changes), a person off balance (feeling off balance), a person lying down (seizures), a person looking like they might throw up (naseau/vomiting), a head with squiggles (confusion)

Verywell / Jessica Olah

Frequent Symptoms 

Symptoms of HER2-positive breast cancer are generally the same as metastatic breast cancer that is not HER2-positive. What symptoms are experienced will depend upon the organ or part of the body where the cancer is growing. The most common sites for breast cancer to spread are the brain, bones, lungs, and liver.


If there is cancer in the brain, symptoms can include:

  • Headaches
  • Dizziness
  • Vision changes
  • Feeling off balance
  • Seizures
  • Nausea and vomiting
  • Confusion


When cancer is growing in the bones, symptoms can include pain in the bone or joint, or maybe swelling in the area around the bone. Sometimes, the cancer weakens the affected bone, increasing the risk of a break, or fracture. 


If cancer cells move into the lungs, it can cause these symptoms:

  • Cough
  • Shortness of breath
  • Pain


If cancer cells spread to the liver, some symptoms that may be seen are:

  • Itching of the skin
  • Yellowing of the skin or whites of the eyes
  • Dark, tea-colored urine
  • Enlargement or swelling of the abdomen
  • Nausea

Rare Symptoms 

It is rare for HER2-positive breast cancer to spread to areas of the body outside of the brain, bones, lungs, and liver. If breast cancer does spread elsewhere, it may cause the following symptoms:


If breast cancer cells invade the eye tissue, there can be visual changes and swelling to the eye.

Reproductive organs

If breast cancer spreads into the female reproductive organs such as the ovaries, uterus, or vagina, there may be pelvic pain or vaginal bleeding.  


HER2-positive breast cancer that spreads into other areas of the body outside of the breast can be a life-threatening problem. 

The cancer cells that invade healthy tissues can cause those other organs to fail. 

When to See a Doctor/Go to the Hospital 

If any symptom that comes up feels like a medical emergency or seems life-threatening, it is important to seek medical help immediately. 

Symptoms that develop gradually and are persistent, without any improvement, should be discussed with your healthcare provider, so that a quick evaluation of the cause of the symptom can be discovered. 


Metastatic HER2-positive breast cancer can cause a variety of symptoms. These symptoms vary depending on the part of the body being affected. Breast cancer most commonly spreads to the brain, bones, lungs, or liver. 

A Word From Verywell

If you have a diagnosis of HER2-positive breast cancer and you start to notice new symptoms, notify your healthcare team quickly. These symptoms should be evaluated to see if metastatic cancer is the reason you’re having them. However, it is also important to remember that not every symptom will be due to cancer.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American Cancer Society. Breast Cancer HER2 status.

  2. Cancer.Net. Breast cancer- metastatic signs and symptoms.

  3. Di Micco R, Santurro L, Gasparri ML, et al. Rare sites of breast cancer metastasis: a reviewTransl Cancer Res. 2019;8(S5):S518-S552. doi:10.21037/tcr.2019.07.24

By Julie Scott, MSN, ANP-BC, AOCNP
Julie is an Adult Nurse Practitioner with oncology certification and a healthcare freelance writer with an interest in educating patients and the healthcare community.