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The Mighty's HER2-Positive Metastatic Breast Cancer Condition Guide

The Mighty’s educational content combines the expertise of both the medical and patient community to support you and your loved ones through your health journeys. For this HER2+ Metastatic Breast Cancer condition guide, we talked with a breast cancer expert, read the latest studies, and connected with more than 160 people living with breast cancer, and caregivers.

HER2-Positive Metastatic Breast Cancer at a Glance:

  • HER2-positive metastatic breast cancer is a specific type of breast cancer that has spread to other areas in the body. 
  • Breast cancer is the most common form of cancer diagnosed in women, and approximately 15% of all breast cancers are HER2-positive. 
  • Although HER2-positive breast cancer can grow and spread more rapidly than other cancers, there are many different treatments available for individuals diagnosed with HER2-positive cancer. 

Medically reviewed by Dr. Rani Bansal, M.D.

What Is HER2+ Metastatic Breast Cancer? | Common Metastatic Breast Cancer Misconceptions | Managing HER2+ Metastatic Breast Cancer | How To Find a Health Care Provider for HER2+ Metastatic Breast Cancer | Mental Health and Metastatic Breast Cancer | How To Talk To Others About Metastatic Breast Cancer | How To Support Someone With Metastatic Breast Cancer | 

What Is HER2-Positive Metastatic Breast Cancer?

HER2-positive metastatic breast cancer is a specific subtype of cancer that originates in the breast tissue and then spreads to other areas of the body. Although the term “breast cancer” may come across in the media as a more “straightforward” diagnosis, there are actually many forms of breast cancer, and understanding what type of breast cancer you have specifically is important to receiving the best treatment. To help you better understand HER2-positive metastatic breast cancer, we’ve created this condition guide. Before we get into the nuts and bolts of this condition, we’re going to take a step back and provide you with an overview of what the “HER2-positive” means in your diagnosis and discuss some more general aspects of breast cancer you should know about. Ready? Let’s get started. 

What Is Breast Cancer Typing?

When a physician suspects you may have cancer, they will order a series of tests to determine what type of cancer you have. You could have a room full of individuals diagnosed with breast cancer and each cancer could be different. That’s why it’s so important to determine what kind of breast cancer you have, as treatments will vary heavily based on your results. 

Some methods for determining breast cancer type include:

  • Biopsy: This procedure is used to take a small sample of tissue from your body to be evaluated by a pathologist, a physician who specializes in visualizing the body and tissue samples. 
  • Immunohistochemistry (IHC) testing: This test is used on the breast cancer cells from your biopsy to determine if the breast cancer cells have increased number of HER2 and  hormone receptors (such as estrogen or progesterone). This test uses chemical stains to see what type of receptors you have and relatively how many. For HER2 typing, test results will be either HER2-positive, negative, or borderline. For hormone typing, this test will see if your cells have receptors for progesterone and/or estrogen, which can act like “fuel” for certain types of breast cancer. 
  • Fluorescence in situ hybridization (FISH) test: This test uses special imaging techniques to determine if a biopsy contains the abnormal HER2 gene that causes the cell to produce too many HER2 receptors. 
  • Other screening, diagnostic, and monitoring tests that may be used to help determine the stage, type, or even presence of cancer include mammograms, thermograms, CT scans, bone scans, MRI scans, and more. You can learn more about the tests and screens you may encounter here

Breast cancer typing will determine if the cancerous cells taken from the biopsy are one of the following four major breast cancer subtypes:

  • HR+/HER2- 
      • Individuals with this subtype will be positive for hormone receptors (estrogen and/or progesterone) and are negative for higher-than-normal levels of HER2 receptors 
  • HR-/HER2-
      • Individuals with this subtype lack both hormone receptors and higher levels of HER2 receptors. This subtype is also known as triple negative breast cancer (TNBC). 
  • HR+/HER2+
      • Individuals with this subtype will be positive for both hormone receptors and higher levels of HER2 receptors
  • HR-/HER2+
      • Individuals with this subtype lack hormone receptors but have higher levels of HER2 receptors

Having hormone receptors present for estrogen and/or progesterone makes these cancer subtypes more susceptible to estrogen and/or progesterone to fuel the cancer cells. You can learn more about these types of receptors here. This condition guide, however, will focus on HER2-positive metastatic cancer. Read on for more details on what HER2 receptors are and why they play a critical role in cancer cell division and growth. 

What Are HER2 Receptors? 

If you research online, you’ll likely come across articles that discuss the HER2 receptor. Breast cancer is very complex and is generally categorized in part by the type of receptors that are present on the cancer cell. 

Cells become cancerous when they grow and divide more rapidly or “out of control” compared to regular, healthy cells. You can think of a cancerous tumor, for example, as a condensed group of cancer cells that are expanding rapidly in one area of the body. 

Cancer cells receive many different signals to grow and one type of signal comes from tiny receptors on the cell. HER2 stands for “human epidermal growth factor receptor 2,” which is a gene in your cell’s DNA that creates these receptors. When you have a cancer biopsy, pathologists will determine whether or not these cells have an abnormal version of this gene. 

In a healthy cell, HER2 receptors help your cells grow, divide, and repair themselves. Those who are HER2-positive have the abnormal gene, which creates extra receptors. That’s why having too many of these types of receptors can cause your cells to grow and divide too rapidly and become cancerous.  

To help visualize these receptors, imagine a long extension cord with lamps sitting next to each open plug. The more lamps you plug in, the more light you would have in the room. HER2 receptors work in a similar way – if a cell has more of these receptors available, then there will be more signals coming to the cell to grow. If you have HER2-positive cancer, your cell’s extension cord may have eight open plugs to use, while others may typically only have two. 

Unfortunately, having extra HER2 receptors on your cancer cells, or being “HER2-positive,” can make your specific type of breast cancer grow more rapidly and be more aggressive than other subtypes. The good news, however, is that HER2-positive cancer is a common subtype of breast cancer, accounting for nearly 15% of all breast cancer cases. Research over the past few years has made incredible advancements and there are treatments that now include HER2-specific targeted therapies. 

Other HER subtypes also include HER2-negative, HER2 Low, and HER3. You can read more about these other HER-specific subtypes here. 

What Is Metastatic Breast Cancer?

When you receive a breast cancer diagnosis, your doctor will likely tell you what subtype of cancer you have along with the stage. Breast cancer stages help physicians and patients better understand the severity and spread of cancer within your body. For example, earlier stages of breast cancer indicate that your breast cancer is likely limited to the breast tissue or nearby lymph nodes. Later stages of breast cancer can include cancer showing up in multiple areas of the breast tissue or growth beyond the breast tissue to other organs. 

A metastatic breast cancer diagnosis means that your cancer originated in the breast tissues and has spread to other organs and areas of the body. Metastatic breast cancer is harder to treat than earlier stages because your physician will have to target many different areas at once. Individuals living with HER2-positive metastatic breast cancer are more likely to have cancer in these areas of the body outside of the breast tissue:

  • Brain
  • Bones
  • Liver
  • Lungs
  • Lymph nodes

If you or a loved one has been diagnosed with HER2-positive metastatic breast cancer, read on for more information on how to work with your physician to get the best treatment. 

Managing HER2-Positive Metastatic Breast Cancer

Because metastatic breast cancer is different for everyone, you and your health care team will develop an individualized treatment plan.

It can be scary to be diagnosed with metastatic cancer, but Dr. Rani Bansal, an oncologist from Brown and Duke University, wants you to know:

“As oncologists, we want our patients to know that they are not alone in their diagnosis and that their health care team will be there alongside them every step of the way. Our goal is to create an individualized treatment plan that is specific to each patient and addresses more than just the treatment of cancer.”

If you or a loved one has been diagnosed with HER2-positive metastatic breast cancer, know that being here and reading this condition guide is a great first step. Given continued advancements in cancer care, each patient’s specific treatment plan may be different. However, learning as much as you can about the different ways to treat this condition will give you further insight on your options and creating a health care team you trust is critical. 

If you looked up metastatic breast cancer online after you received the diagnosis, you may be overwhelmed by what you have found. You may be asking yourself: 

  • What does treatment for HER2-positive metastatic breast cancer look like?  
  • How will metastatic breast cancer affect my day-to-day life? 
  • What is the prognosis for patients with HER2-positive metastatic breast cancer? 

Treatment regimens for HER2-positive metastatic breast cancer will, in part, depend on where the cancer has spread to in your body, your specific breast cancer subtype, and the treatment options available from your health care team.

Some options that you may be recommended by your care team include pharmaceutical options, such as oral or infusion systemic therapy (such as chemotherapy, targeted therapy, or immunotherapy) radiation, surgical options, and self-care or non-pharmacological options.


Chemotherapy is a medical treatment that uses powerful drugs to target and kill cancer cells. This type of therapy is usually given over multiple sessions in cancer treatment clinics also known as infusion centers. Chemotherapy may be used to remove all of the cancerous cells, or to help shrink tumors before surgical removal. 

Targeted Therapies 

Over the past decade, targeted therapy options specifically for HER2-positive cancers have been a game-changer for treatment. New, highly-effective drugs are used to target HER2 receptors specifically. There are many different targeted therapy options, which range from taking pills to IV therapies and treatments to combinations of both. 

Radiation Therapy

Radiation therapy is a form of treatment that uses radiation (high beams of energy) to target specific areas of the body to kill cancer cells. Radiation therapy may be used to help reduce tumor sizes before surgical treatment or used after surgical treatment to prevent the recurrence of cancer. For individuals with metastatic breast cancer, radiation therapy is often used to help manage symptoms of pain or discomfort such as from cancer that is involving the bone and causing bony pain. This is termed “palliative radiation” as the goal of radiation is to palliate symptoms. 

Surgical Treatment 

Surgical treatments are used to physically remove tumors and other regions affected by cancer from the body. Surgical treatment could include a mastectomy, removal of the entire breast; lumpectomy, removal of a tumor; or even removal of other areas of the body that have become cancerous or may become cancerous like the lymph nodes. Surgical treatments are more often used in the localized treatment setting. In the metastatic setting, surgical treatments usually have less of a role but in certain cases may be used. 

Combination Therapy 

When you discuss treatment options for HER2-positive metastatic breast cancer, you will likely be prescribed a combination therapy. Combination therapy is when an oncologist uses different treatment options together to create the best possible outcome. Example combinations could include chemotherapy to reduce tumor size before removal of the tumors surgically or the use of chemotherapy and targeted therapies together. There are now medications that have combined chemotherapy and targeted therapy drugs together to produce a stronger effect against cancer cells. Every person’s treatment regimen will be different depending on where the cancer has spread or how extensive it is, among many other factors. 

Self-care and Non-Pharmacological Options to Help Manage Living With Metastatic Breast Cancer

HER2-positive metastatic breast cancer can have vast effects on the body. Treatments for breast cancer can be extensive, and each treatment has its own potential side effects. Your care team will help you manage those side effects as best as possible, but there are some strategies you can use to help make managing the process easier on your own. 

Here are some tips community members suggested that might help:

  • Massage therapy 
  • Meditation or deep breathing exercises
  • Yoga
  • Eating a healthy diet and exercising regularly 

Some other aspects of living with breast cancer that you should consider include:

  • Possibility of hair loss due to treatment
  • Family planning and effects of treatment on fertility or ability to have children 
  • Mobility if treatment or cancer has affected your ability to walk or your energy levels

Living with any form of breast cancer can be a scary experience, but know that there are many people who have been through this experience – you are not alone! You can find support from others or find tips on speaking with your health care team on The Mighty’s breast cancer topic page.

What Does “Successful” Treatment for HER2-Positive Metastatic Breast Cancer Look Like?

When diagnosed with cancer, the first questions many people will have are around life expectancy and how likely you’ll be able to be cured from it. Answering this question can be challenging, even for a physician who knows all the ins and outs of your specific cancer diagnosis because each person’s cancer is unique. 

HER2-positive metastatic breast cancer overall is considered incurable. However, there are many treatment options, and reaching remission or a place of stability with the cancer is possible if your particular cancer responds well to treatment. To learn more about HER2-positive metastatic breast cancer, we talked to Dr. Rani Bansal, an oncologist, about what she considers “success” in treatment for HER2-positive metastatic breast cancer. Here’s what she said:

“I want [my patients] to be able to live their life and be able to do everything that they want to do, and have that for as long as possible. Unfortunately, I can’t take their breast cancer 100% away, but I can try to get it to a point where it’s controlled, and it’s not affecting their everyday life.”

If you’re feeling apprehensive about receiving a HER2-positive breast cancer diagnosis, that’s OK! Know that there are people willing and able to help you navigate this journey. Finding an oncologist you trust, and surrounding yourself with a support team is a key first step. You can read more about finding a doctor and who you might consider for your health care support team below.

How to Find a Doctor for HER2-Positive Metastatic Breast Cancer

Finding the right care team for any metastatic cancer can be challenging, but it’s key to getting the best outcome. Where should you begin? 

First, identify an oncologist (cancer specialist) and primary care physician you trust and feel comfortable with. Your oncologist and primary care physician can help you find the right specialists to help in your care. 

Different healthcare professionals can help manage a HER2-positive metastatic breast cancer diagnosis, including:

  • Primary care physician (PCP)
  • Oncologist 
  • Plastic surgeon, if you have surgical treatments
  • Specialists associated with areas the cancer affects, i.e. a gastroenterologist if your metastatic cancer affects your GI system.
  • Occupational therapist/ physical therapist
  • Mental health professional 

In a recent survey of Mighty members, 76% of respondents said an oncologist helped them make a decision about treatment. Twenty-three percent said their primary care physician helped them as well. Together, these two professionals along with any others in your care team can help provide the best path forward in managing your HER2-positive metastatic breast cancer. 

To help you navigate this journey, we created a downloadable discussion guide to help you prepare for a visit with your oncologist to help discuss your breast cancer diagnosis and next steps. We hope this guide helps you get the most out of your appointments:


It can be scary to receive any cancer diagnosis, and looking up treatments online can feel very daunting because of the volume of studies and potential therapies available. But don’t worry – that’s a good thing! There is a lot of research being conducted to help improve treatment outcomes for people living with cancer and your health care team will help you navigate it. You are not alone in this journey. 

Breast Cancer Misconceptions

Unfortunately, breast cancer is a common experience in our communities. However, there are misconceptions about the condition that can make life more challenging for those experiencing it. To better understand what they’re going through, we asked individuals living with breast cancer and their caregivers what they wish others understood. Here’s what they had to say:

  1. “The breast cancer journey does not end with treatment. There are continued medications, side effects, follow-ups/checkups, and the constant fear of recurrence.”
  2. “Once the treatment is finished it is NOT all over. Once you’ve had that diagnosis you are never the same again. Every bump, pain, etc., and you [feel like you’re] right back to the beginning again and it’s scary.”
  3. “I wish that the ‘positive thoughts only’ notion could be dispelled once and for all. It has *not* been proven that positive thinking helps cure or even stabilize breast (or any other kind of) cancer, plus it creates a lot of unhelpful and unhealthy toxic positivity for breast cancer victims; often we aren’t allowed to express or even acknowledge our dark thoughts or painful emotions.”
  4. “I wish they understood that how they see my wife present herself positively isn’t how things really are. Just because my wife has a good attitude doesn’t mean it’s been an easy process. I wish they would stop using silly cliches like ‘everything happens for a reason’ in describing our journey. Those comments are 100% unhelpful because they attempt to artificially rationalize human suffering.”
  5. “How lonely and frightening and overwhelming it can be, sometimes out of the blue. The mental health battle can be massive.”  
  6. “I wish that the males in my family were more proactive since the BRCA2 mutation is a possibility. Also, [I wish that] the wider population was more aware that males do get breast cancer.”

We hope that reading what the breast cancer community shared above can help you better navigate and understand some of the challenges people living with breast cancer face. You may see your friend, family member, or community member look “fine” or “strong enough” to handle their journey with breast cancer. Just remember – they didn’t sign up to be strong, they had to be to survive, and that doesn’t mean they also don’t struggle at the same time with their cancer journey before, during, and even after treatment. 

Mental Health and Metastatic Breast Cancer

It’s important to remember that living with breast cancer can also affect your mental health. 

In a survey of more than 160 people with breast cancer on The Mighty, 71% of respondents said that they experience depression or sadness. Sixty-nine percent reported feeling anxiety or panic symptoms. Receiving a breast cancer diagnosis can be scary, and may surface many worries or fears for the future. Mental health is often overlooked in health care and isn’t often a core aspect of cancer treatment plans. This issue is highlighted in our survey where 68% of all respondents to our survey said that the most difficult day-to-day challenge of living with breast cancer was actually the impact cancer had on their mental and emotional health, not the side effects of treatment. 

If you are struggling with your mental health while living with breast cancer, know that mental health professionals are available. Seeking help does not make you less “strong,” it is simply an act of kindness to yourself, a way you can help yourself become stronger in different ways, not strong in the first place. You may be thinking, “but I have cancer and my anxiety or depression is just around the cancer – how will a therapist understand the experience?” Luckily, there are therapists and other mental health professionals who specialize in therapy for individuals who have experienced cancer. 

It’s important to note that it’s OK if you’re still feeling anxious, depressed, or stressed even if you are in remission. You may still feel the effects of cancer on your mental health even after everything is “OK” with the cancer itself. Forty-two percent of individuals we surveyed stated that they had questions about support after treatment, especially around recurrence. Stress around scans is real and valid, and finding support can help with that process. 

Other aspects of breast cancer that can impact your mental health are treatment-related side effects like fatigue, pain, and hair loss. Body image can be affected by hair loss and surgical treatment. Know that getting plastic surgery after treatment is something you can pursue – and not feel “weird” about! There are even plastic surgeons who specialize in options for breast reconstruction after cancer treatment. 

It can be hard to be vulnerable, but opening up to your health care provider and a therapist is important. These conversations may give you coping strategies and treatment options to improve your quality of life. To help in those moments where you might need extra support, we created this Mighty feelings wheel with common physical sensations and emotions. It’s a great visual tool for sharing with loved ones or someone on your treatment team. As a bonus, coloring in the sections that best match what you’re feeling can be a welcome distraction, too!

Breast cancer feelings wheel toolkit sheet.


How to Get Help in a Crisis

If you’re struggling with suicidal thoughts, know you are not alone. There is help for people who feel suicidal. If you need help right now, you can call the National Suicide Prevention Lifeline at 1-800-273-8255 or text “START” to 741-741. Head here for a list of crisis centers around the world and visit our suicide prevention resources.

How to Talk to Others About Metastatic Breast Cancer

A metastatic breast cancer diagnosis can be difficult for you to receive, and also for others to hear. There will be concerns and fears from both sides and everyone reacts differently to stressful situations. One tool you can use along the way is information from your health care team and other breast cancer advocates who know what you’re going through. By better understanding what you’re about to experience or currently experiencing together, you and your loved ones will be better equipped. 

While this journey can be challenging and trying to navigate it can be draining (you’re doing a great job, by the way), we hope you can feel comfortable talking about what you’re going through, whether that’s with your doctor, your friends, your partner or even a fellow Mighty on our app. No matter what, our Mighty community is here to help. We’ve got your back. 

It’s important to be open about your needs and limits to your family, friends, work colleagues, and community. You may encounter a situation where a family member or friend wants you to participate in an activity that is more difficult because of your cancer or cancer treatment. For example, they may not know how much your treatment affects your energy levels or if certain activities are painful. It may be tempting to just “fake it ‘til you make it” for a while. But your energy is precious – take the rest you need. Yes, you can come first! 

Being open with your family and friends about your limits and needs doesn’t make you “too much.” Saying “no” won’t make you a “worse” friend. Your group wants to be with you because of who you are. So be your own best advocate. After all, no one knows your body and its limits better than you do.

Try taking the lead and invite your group to a breast cancer-friendly activity:

  • Organize a Netflix watch party 
  • Start a virtual book club with friends
  • Organize a playdate for your children, so that they can be entertained while you and a friend do a calm activity like sitting outside listening to music or watching a movie
  • Learn a new craft, especially one that can be done with a limited amount of energy

If you’re struggling at work, especially during treatment, know that there are options available to help through your employer’s human resources (HR) department. You may be eligible to go on short or long-term disability, or Family and Medical Leave (FMLA). Accommodations may be made to help you complete your work, such as working remotely, assistive devices if you experience pain, or different work hours to better accommodate your treatment schedule. You may also be able to access free mental health resources with your employer’s health insurance plan or HR benefits. 

We know it can be tough to communicate your needs and experiences with people in your support system (especially on rough health days), so we created the worksheet below for you to fill out when you’re feeling up to it. Share it with those who are eager to learn more about what you go through with metastatic breast cancer. We hope this can be a bridge to better communication for everyone. You all deserve it.

My life with breast cancer worksheet.


How to Support Someone Living With Breast Cancer

Supporting someone who lives with breast cancer can be challenging. But here’s the bottom line: Being present and willing to learn more about what they’re going through is what matters most. You don’t have to be an oncologist who specializes in breast cancer to be a key supporter for someone living with it. 

The key to success is good, open communication paired with active listening. Don’t make assumptions about what they’re going through. Fifty-six percent of the individuals we surveyed about their experience with breast cancer said that connecting with friends and family helped support their mental health and journey with cancer. And that’s where you come in – ask them what would help them, and respect their answer. Maybe you’re the friend that’s in the “no cancer zone” they can connect to without any mention of cancer, even if it’s just for five minutes. Perhaps you’re the one they have a separate text thread with where they can share their worries and fears without feeling like they’re being “too much.” Whatever it looks like with your friend, family member, or even community member, know that you’re a part of their support network. 

You don’t have to be a specialist to help them along their journey, but becoming knowledgeable about the type of cancer and treatment they’re experiencing can help a lot. They may be overwhelmed and need some help researching options or organizing all of their information. Sixty-nine percent of our survey respondents said that spending time researching or gathering information on breast cancer was helpful to support their mental health and cancer journey. Just remember: If the person you’re trying to support doesn’t want to talk about their diagnosis in detail, don’t force it. Everyone will have their preferred way of navigating their journey with cancer. 

There are many other ways you can help support someone living with breast cancer. Here are some suggestions the community highlighted:

  • Offer to drive them to and from treatments
  • Be a notetaker during doctor’s appointments 
  • Help with childcare 
  • Help find resources around cancer treatments and insurance costs
  • If you’re a breast cancer survivor or are also undergoing treatment, share your experiences
  • Assist with cleaning the house, washing clothes, or preparing meals, especially after treatment sessions 
  • If they ask, help find a mental health professional who can provide further support

Cancer treatment and beyond can be a long journey. Everyone’s experiences will be different but just reading this educational resource is a thoughtful first step. Thanks for being here. 

This condition guide was created with support from many Mighty contributors and medical experts. You can learn more about the individuals interviewed for the creation of this resource here:

  • Rani Bansal, M.D. 
  • Tammy Polo
  • Lauren Rockwell, MSW

And to the Mighties who took our breast cancer survey: thank you!

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