If you've been diagnosed with HR+/HER2- breast cancer, you’ve probably heard some phrases that can feel overwhelming. One of those is "genetic mutation." These are changes in the DNA of your cancer cells that can affect how your cancer behaves — and how your doctors treat it.
You and your doctor will work closely together to find the path that works best for your life and your cancer.
How Genetic Mutations May Guide Treatment Decisions
Your doctor will recommend they test your tumor for genetic mutations. To do this, they look at your tumor under a microscope and run tests on it. Two better-known examples of genetic mutations that affect your cancer risk and treatment options are BReast CAncer gene 1 (BRCA1) and BReast CAncer gene 2 (BRCA2). If you have these genetic mutations, you were most likely born with them.
But other genetic mutations can also affect your breast cancer risk, treatment, and progression. PIK3CA, AKT1, and PTEN are three genes that play a role in how cancer grows. Knowing if you have changes in them can help guide your treatment choices. PIK3CA and AKT1 genetic mutations aren't changes you were born with. They happen in your cancer cells. PTEN genetic mutations can either be inherited (you’re born with them) or develop later in life.
Here’s what these specific mutations mean:
- PIK3CA helps control how cells grow and survive. When it’s mutated, it can cause cells to grow too fast, which can lead to cancer. About 30%-40% of people with HR+/HER2- breast cancer have a PIK3CA mutation. Luckily, there are drugs made just for this. For example, alpelisib (Piqray) is a targeted therapy that blocks the overactive PI3K pathway. Your doctor may combine it with a hormone-blocking drug called fulvestrant if your cancer comes back or spreads after other treatments.
- AKT1 helps with cell growth. A mutation in this gene also affects a pathway that controls how your cells grow and survive. AKT1 is like a switch that tells cells to keep growing. If it's stuck in the “on” position, cancer can grow more easily. A drug called capivasertib (Truqap) can help block the “on” switch.
- PTEN works like a brake pedal, slowing down the effects of PIK3CA and AKT1. It stops cells from growing too quickly. If it’s missing or not working right, cancer cells can grow unchecked. PTEN mutations are more complicated. There isn’t a specific drug made just for this mutation, but your doctor may still use an AKT inhibitor (such as capivasertib) as part of your treatment, or they may suggest you join a clinical trial.
Genetic Mutations and Chance of Recurrence
Your cancer’s gene changes can affect how aggressive your cancer is and how likely it is to come back. Your doctor can’t say for sure whether that will happen, but your genetic mutations can give some clues.
For example:
- If you have a PTEN mutation or loss, your cancer may be more aggressive. Your doctor may watch you more closely or suggest clinical trials for newer therapies.
- A PIK3CA mutation can mean your cancer is a little more likely to come back after treatment. Targeted therapy may help lower that risk. When you use them correctly, targeted therapy can lower your chance of recurrence.
Overall, if you have a PIK3CA, AKT1, or PTEN mutation, your doctor might recommend more frequent checkups. You may get access to new drugs that lower your chance of recurrence, and you could be eligible for a clinical trial testing a new treatment.
Remember, just because you have one of these mutations doesn't mean your cancer will come back. It means your doctor has more info to help choose the best plan for you.
Team Up With Your Doctor
Knowing whether you have mutations like PIK3CA, AKT1, or PTEN gives you more power to understand your HR+/HER2- breast cancer and how best to treat it. It helps you and your doctor choose treatments that are more likely to work and manage the risk of your cancer coming back. Don’t be afraid to ask questions. Make sure you understand your options so you can feel confident in your care.
There are ways to make conversations with your doctor more helpful and less confusing. Don’t be afraid to ask them to slow down or explain things in simpler terms. It’s OK to say, “I didn’t understand that. Can you say it a different way?”
Having open, honest talks with your doctor is one of the best ways to stay on top of your care. Here are some tips:
Ask about genetic testing. Not everyone gets tested for mutations like PIK3CA, AKT1, or PTEN right away. Ask your doctor if it makes sense for you. You can ask:
- Has my tumor been tested for genetic mutations?
- How can I get tested for genetic mutations?
- What does the test involve?
- How long does it take to get results?
Talk about the results. If you do have a mutation, ask your doctor what that means. Will it change your treatment plan? Does it mean your cancer is more or less likely to come back? You can ask:
- Can you explain what the results mean for my treatment?
- Are there treatments that target these mutations?
Set clear goals. Tell your doctor what’s most important to you. Is your goal to avoid chemo? Stay on track with work or school? Understanding your priorities helps your doctor guide you through treatment. You can ask:
- Will these drugs help reduce my risk of recurrence?
- What is the goal of treatment?
Ask about side effects. Targeted therapies can have some side effects. Ask how likely they are and how you can manage them. You can ask:
- What are the side effects of this treatment?
- Will it affect my energy, appetite, or mood?
- How can I treat side effects that bother me?
Discuss clinical trials. If you have a less common mutation like AKT1 or PTEN, ask if there are clinical trials or new treatments being studied that you could try. You can ask:
- Would I be a good fit for a clinical trial?
- How do I find clinical trials?
- How long would a clinical trial last?
- Would I have to pay for a clinical trial?
Show Sources
Photo Credit: EyeEm/Getty Images
SOURCES:
National Cancer Institute: “BRCA Gene Changes: Cancer Risk and Genetic Testing.”
BMC Cancer: “PIK3CA mutation status, progression and survival in advanced HR + /HER2- breast cancer: a meta-analysis of published clinical trials.”
MedlinePlus: “ATK1 Gene,” “PTEN Gene.”
New England Journal of Medicine: “Capivasertib in Hormone Receptor–Positive Advanced Breast Cancer.”
Nature: “A retrospective analysis suggests PTEN expression is associated with favorable clinicopathological features of breast cancer.”
Physiological Research: “PTEN Mutations as Predictive Marker for the High-Grade Endometrial Cancer Development in Slovak Women.”
American Cancer Society: “Questions to Ask Your Doctor About Breast Cancer.”
Memorial Sloan Kettering Cancer Center: “Questions to Ask Your Doctor about Clinical Trials.”
