Certain women age 70 to 80 may be able to skip chemotherapy after surgery for early-stage HER2-positive disease and be treated only with Herceptin (chemical name: trastuzumab), according to a study.
The research was published online on Sept. 16, 2020, by the Journal of Clinical Oncology. Read “Randomized Controlled Trial of Trastuzumab With or Without Chemotherapy for HER2-Positive Early Breast Cancer in Older Patients.”
Why the study was done
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.
Because HER2-positive breast cancer is considered more aggressive than HER2-negative breast cancer, it is usually treated with a combination of Herceptin, an anti-HER2 medicine, and chemotherapy after surgery.
Still, older women have a higher risk of side effects from chemotherapy. So the researchers wanted to see if treating older women diagnosed with early-stage HER2-positive disease with Herceptin alone after surgery offered the same benefits as treating them with Herceptin plus chemotherapy.
About the study
This Japanese study, called the RESPECT trial, included 266 women age 70 to 80 who were diagnosed with early-stage HER2-positive breast cancer from October 2009 to November 2014.
Characteristics of the breast cancers:
- 116 (44%) were stage I
- 111 (42%) were stage IIA
- 36 (13.5%) were stage IIB
- 3 (1%) were stage IIIA
- 80% of the cancers were node-negative (no cancer was found in the lymph nodes)
As far as surgery, 69% of the women had mastectomy and 30% had partial mastectomy.
Many of the women had other health conditions, including:
- 118 women (44%) had high blood pressure
- 25 women (9%) had diabetes
- 28 women (10.5%) had osteoporosis
- 70 women (26%) had high cholesterol
The women were randomly assigned to one of two treatments after breast cancer surgery:
- 135 women were treated with Herceptin alone
- 131 women were treated with Herceptin plus chemotherapy
The women were followed for an average of 4.1 years. The researchers looked to see if disease-free survival, overall survival, and side effects were different between the two treatment groups. The researchers also assessed the women’s health-related quality of life.
Disease-free survival is how long the women lived without the cancer coming back. Overall survival is how long the women lived, whether or not the cancer came back.
Three-year disease-free survival rates were:
- 89.5% for women treated with Herceptin alone
- 93.8% for women treated with Herceptin and chemotherapy
Three-year overall survival rates were:
- 97.2% for women treated with Herceptin alone
- 96.6% for women treated with Herceptin and chemotherapy
The analysis showed that the difference in survival at 3 years was less than 1 month.
Side effects and quality of life
Women treated with Herceptin and chemotherapy were more likely to have a severe side effect (grade 3 or 4) not related to blood counts compared to women treated with Herceptin alone — 29.8% vs. 11.9%.
The most common side effects of any grade were:
- low white blood cell counts
- loss of appetite
- hair loss
Health-related quality of life scores went down faster in women treated with Herceptin plus chemotherapy, compared to women treated with Herceptin alone, 2 months after starting treatment and 1 year after starting treatment.
“In light of the lower toxicity and more favorable [health-related quality of life] profile, trastuzumab monotherapy can be considered an adjuvant therapy option for selected older patients,” the researchers wrote.
In an editorial accompanying the article, researchers not affiliated with the study agreed with the conclusion.
“…on the basis of the results of the RESPECT trial, it is possible to consider that adjuvant trastuzumab monotherapy could be an option for a subset of patients, particularly those who may have a higher risk of toxicity with chemotherapy and those with a lower anatomic risk of disease recurrence (stages I or IIA),” they wrote. “It is important to stress, however, that the choice of therapy in older patients should never be made on the basis of age alone. Comprehensive geriatric assessment is the standard of care for evaluation before chemotherapy and should generate a care plan to be implemented during treatment to minimize the risk of complications and maintain [quality of life] and functionality.”
What this means for you
If you’re a woman age 70 to 80 diagnosed with early-stage HER2-positive breast cancer, the results of this study are encouraging.
As you’re talking with your doctor about treatments after surgery, you may want to bring up this study and ask if Herceptin alone vs. Herceptin plus chemotherapy would be a good option for your unique situation.
You and your doctor will consider a number of factors when deciding on treatments, including:
- the characteristics of the breast cancer
- any other health conditions you have
- your personal preferences
Together, you can make the best decisions for you.
Written by: Jamie DePolo, senior editor
Reviewed by: Brian Wojciechowski, M.D., medical adviser
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