If you’ve just been diagnosed with hormone receptor-positive (HR-positive)/human epidermal growth factor receptor 2-negative (HER2-negative) breast cancer, a lot of terms are coming at you fast.
You probably have a lot of questions, too. Among them, one may ring the loudest: What are my chances of surviving this?
“When someone comes to us with stage 0 to III breast cancer, it’s not just treatable, it’s curable,” says Abirami Sivapiragasam, MD, breast oncologist and director of medical oncology at Medical University of South Carolina Hollings Cancer Center.
HR-positive/HER2-negative is the most common type, accounting for around 70% of all breast cancers. Understanding what it is and the survival rates at each stage will help you understand why treatment is crucial for the best outcome.
What Does HR-Positive/HER2-Negative Mean?
When your doctor discovers you have breast cancer, one of the first things they do is test the tumor to see if it has certain receptors. Those are proteins on the outside of cells.
Having HR-positive/HER2-negative breast cancer means your cancer is:
Hormone receptor-positive (HR-positive). HR-positive cancer cells have receptors for the hormone estrogen, progesterone, or both on their surface. That means estrogen and/or progesterone are what your cancer cells use as fuel to grow.
Human epidermal growth factor receptor 2-negative (HER2-negative). This means your cancer cells don’t have a spiky, antennae-like receptor on their surface called HER2. Cancer cells with HER2 proteins tend to be more aggressive and spread quickly.
This information makes your cancer more predictable, says Arif Kamal, MD, chief patient officer for the American Cancer Society and oncologist at Duke Cancer Center. And that means your doctors have a better shot at controlling — and curing — it.
“Most cancers are what I call ‘zombie cars.’ We don’t know what makes them run or how to turn that off,” Kamal says. “But in HR-positive cancers, we know that fuel source, and we can cut it off.”
This has made all the difference in how effectively doctors can treat breast cancer, drastically raising survival rates.
“Breast cancer mortality has gone down by 44% in the last 30 years,” Kamal says. “That’s one of the major good news stories in cancer.”
Understanding Survival Rates
Doctors typically talk about survival rates using five years as a benchmark. A five-year survival rate is the percentage of people still alive five years after diagnosis.
For example, a 95% survival rate means that five years after diagnosis, 95% of people diagnosed are still alive. The 5% who die in that time period may have died because of their diagnosis or another reason.
HR-positive/HER2-negative survival rates
People with HR-positive/HER2-negative breast cancer have higher survival rates compared to those with other subtypes of breast cancer. Overall, the five-year survival rate of HR-positive/HER2-negative breast cancer is 95.6%.
When you look at survival rates of different subtypes of breast cancer side by side, you get:
- HR-positive/HER2-negative: 95.6%
- HR-positive/HER2-positive: 91.8%
- HR-negative/HER2-positive: 86.5%
- HR-negative/HER2-negative: 78.4%
HR-negative/HER2-negative is also called “triple-negative.” This is because it’s negative for both kinds of hormone receptors — progesterone and estrogen — and doesn’t have a HER2 protein on it. Triple-negative breast cancer is more difficult to treat than other subtypes.
“Triple-negative cancers are wild cards, because we can’t predict what they’re going to do,” Kamal says. “We don’t know what makes them grow, which means we don’t know how to stop them from growing.”
It’s important to remember that survival rates are constantly changing. They’re only a reference point.
“Survival rates are calculated based on past experience from people who went through this five years ago,” Sivapiragasam says. “So, whoever we see now is going to have even better numbers than these.”
How Does Cancer Stage Affect My Survival Rate?
Your cancer stage tells your doctor how far cancer has spread in your body. The lower the number, the less your cancer has spread.
“Stage has everything to do with the distance the cells have traveled compared to where they started.” Kamal says. “Stage is very important to categorize when somebody is presenting to us because based on that categorization, we can allocate appropriate treatment options.”
Stage 0. Doctors sometimes call this “noninvasive” or “in situ,” which means it’s where it originally started. Cancer cells are in the ducts of your breast only, not your breast tissue.
Stage I. Cancer cells have spread into your breast tissue, and your tumor is under 2 cm. If it’s stage IA, there are no cancer cells in your lymph nodes. If it’s stage IB, cancer has spread to your lymph nodes.
Stage II. Your cancer has spread to 1-3 lymph nodes or is 2 cm or larger and hasn’t spread to lymph nodes.
Stage III. Your cancer has spread to 4 or more lymph nodes or has spread to the chest wall. Or the cancer is larger than 5 cm and has spread to 1-3 lymph nodes.
Stage IV (metastatic). Cancer has spread to other parts of the body, such as the bone, liver, or lungs.
“Stage IV patients have a completely different treatment pathway that we use because unfortunately, this stage is not curable, but it’s still very, very treatable with multiple medications that we have,” Sivapiragasam says.
Survival rates for each stage depend on many factors, such as how many lymph nodes and how much tissue is involved. But personal health is important when predicting your survival rate, too.
“We have to look at whether you’re premenopausal or postmenopausal. We look at your age. We look at your comorbidities,” Kamal says.
In general, survival rates go down as the stage goes up. Roughly that looks like:
Stage 0. Nearly 100%
Stage I. 95%-99%
Stage II. 90%-93%
Stage III. 85%-89%
The less your cancer has spread, the better doctors can target it and make sure the cancer cells are gone. With stages 0 to III, doctors have a real shot at curing your disease with surgery. Everything done after that, such as hormonal therapy, radiation, or chemotherapy is to lower the chance of your cancer coming back.
Why Treatment Matters
Treatment greatly improves survival. Without treatment, HR-positive/HER2-negative breast cancer almost always grows and gets worse.
“From an easy-to-cure situation with treatment, you are going to an incurable, lethal situation without it,” Sivapiragasam says. “Even if you don’t want chemo, radiation, or hormonal therapy, you should go for surgery because that’s the first step to get you to the curative status. If you don’t have surgery, then from stage I to III, almost every single time, we know that the cancer is unfortunately going to progress.”
