Herceptin (chemical name: trastuzumab) is a targeted therapy medicine used to treat HER2-positive breast cancer.
Findings from a large review study found that women diagnosed with HER2-positive breast cancer that was treated with Herceptin were less likely to have the cancer come back (recur) and more likely to survive compared to women who didn't get Herceptin.
The findings were published online on April 18, 2012 in The Cochrane Library. The Cochrane Library catalogues information from the Cochrane Collaboration, a highly respected program that helps doctors and patients decide on the best treatment approaches based on careful analysis of available research. Read the abstract and plain language summary of Trastuzumab containing regimens for early breast cancer.
HER2-positive breast cancers make too much of the HER2 protein. The HER2 protein sits on the surface of cancer cells and receives signals that tell the cancer to grow and spread. About one out of every four breast cancers is HER2-positive. HER2-positive breast cancers tend to be more aggressive and harder to treat than HER2-negative breast cancers.
Herceptin works by attaching to the HER2 protein and blocking it from receiving growth signals. Herceptin, which is given intravenously, is approved by the U.S. Food and Drug Administration to:
- treat advanced-stage, HER2-positive breast cancers
- lower the risk of recurrence (the cancer coming back) of early-stage, HER2-positive breast cancers with a high risk of recurrence
This study was a meta-analysis. A meta-analysis combines and analyzes the results of a number of earlier studies. In this case, results from eight studies looking at the benefits and risks of Herceptin were in the meta-analysis. Nearly 12,000 women were in the studies. All the women had been diagnosed with either early-stage or locally advanced HER2-positive breast cancer. Besides surgery, treatments included chemotherapy and hormonal therapy (if the cancer was hormone-receptor-positive). Some of the women got Herceptin and others didn’t. The women were followed for about 3 years after they were diagnosed.
Compared to women who didn’t get Herceptin, women who did:
- were 36% less likely to have the cancer come back
- were 40% less likely to die from breast cancer
Women who got Herceptin for a full year got the most benefits.
Herceptin may cause side effects, including:
- high blood pressure
- joint and back pain
- hot flashes
Some women getting Herceptin will have decreased heart function during treatment. In rare cases, heart failure can develop. Other studies have shown that heart problems caused by Herceptin are more likely to happen in older women, women with diabetes, and women with preexisting risk factors such as high blood pressure, high cholesterol, and obesity. Heart function can recover when Herceptin treatment stops.
In this study, women who got Herceptin were five times more likely (2.6% vs. 0.5%) than women who didn't get Herceptin to develop heart problems during and after treatment. All the women had normal heart function before starting Herceptin treatment.
To better understand a study’s results, it sometimes helps to look at them in terms of large groups of people. So based on this study, if 1,000 women got standard breast cancer treatments but not Herceptin:
- about 900 would survive
- about 645 would have no recurrence
- about five would have a heart problem during or after treatment
If 1,000 women got Herceptin for 1 year and other standard breast cancer treatments:
- about 933 would survive (33 more than women who didn’t get Herceptin)
- about 740 would have no recurrence (95 more than women who didn’t get Herceptin)
- about 26 would have a heart problem during or after treatment (21 more than women who didn’t get Herceptin)
While Herceptin has risks, this large review clearly shows that Herceptin can improve prognosis in women diagnosed with HER2-positive breast cancer. If Herceptin is or will be part of your breast cancer treatment plan, you may want to ask your doctor about your personal risk of Herceptin-related heart problems and how your heart function will be evaluated before, during, and after Herceptin treatment.
In the Breastcancer.org Herceptin pages, you can learn more about how Herceptin works, when it's used, and what to expect during treatment.