Herceptin (chemical name: trastuzumab) is a targeted therapy medicine used to treat HER2-positive breast cancer.
Eleven years of follow-up information from the HERA trial confirms that 1 year of Herceptin, rather than 2, after surgery and chemotherapy is best for reducing the risk of recurrence (the cancer coming back) in women diagnosed with HER2-positive, early-stage breast cancer.
The research was published in the March 2017 issue of The Lancet. Read the abstract of “11 years’ follow-up of trastuzumab after adjuvant chemotherapy in HER2-positive early breast cancer: final analysis of the HERceptin Adjuvant (HERA) trial.”
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 of early-stage, HER2-positive breast cancers with a high risk of recurrence
Treatments given after surgery to reduce the risk of recurrence are called adjuvant treatments.
This study offers long-term results from the HERA (Herceptin Adjuvant) trial. More than 5,000 women diagnosed with early-stage, HER2-positive breast cancer participated in the HERA trial, which started in 2001.
Besides surgery (followed by radiation therapy in many cases), all of the women got chemotherapy, either before surgery, after surgery, or both before and after surgery. After chemotherapy was done, the women were randomly assigned to one of three treatment groups:
- Herceptin for 1 year (1,702 women)
- Herceptin for 2 years (1,700 women)
- placebo (a dummy infusion) for either 1 or 2 years (1,697)
After 1 year of follow-up, an early analysis showed the women who got Herceptin had a 46% lower risk of recurrence compared to those who didn't get Herceptin. Because these early results were so promising, HERA ended early in 2005 and the women who didn't get Herceptin could start Herceptin if they wanted to (called crossing over); many of them chose to start Herceptin.
The latest HERA analysis includes 11 years of follow-up, comparing the results of women who got Herceptin for 1 year to women who got Herceptin for 2 years.
The researchers found that 2 years of Herceptin doesn’t offer any more benefits than 1 year of Herceptin.
Ten-year disease-free survival rates were:
- 69% for women who got 1 year of Herceptin
- 69% for women who got 2 years of Herceptin
- 63% for women who got placebo
Ten-year disease-free survival rates are the numbers of women who were alive with no breast cancer recurrence 10 years after first being diagnosed.
The researchers also reported that women who got Herceptin were about 26% less likely to die from breast cancer than women who got the placebo.
Women treated with Herceptin sometimes have serious side effects, including:
- heart failure
- high blood pressure
- joint pain
- back pain
- hot flashes
Still, serious side effects were seen in a low percentage of the women who got Herceptin in the HERA trial.
The results of the HERA trial reinforce the current treatment standard: getting Herceptin for 1 year after surgery and other treatments is best for reducing recurrence risk in women diagnosed with early-stage, HER2-positive breast cancer.
If you’ve been diagnosed with early-stage, HER2-positive breast cancer, your doctor will likely recommend Herceptin for 1 year (and possibly other treatments) after surgery to reduce the risk of the cancer coming back. If your doctor recommends Herceptin for a length of time other than a year, it’s a good idea to ask why and talk about this study. Together, you and your doctor can decide on a treatment plan that makes the most sense for you and your unique situation.