Among women who received treatment for early-stage, HER2-positive breast cancer, age at diagnosis was not associated with greater risk of recurrence—the cancer returning—or increased death rates for up to 2 years after treatment began, a recent study showed.
The research was published in the Journal of Clinical Oncology.
Breast cancers are tested for the presence or absence of individual tumor characteristics, including a protein known as HER2, or human epidermal growth factor receptor-2. This testing helps determine what treatments the tumor will best respond to.
HER2 signals breast cancer cells to grow and divide. When a greater than normal number of HER2 proteins are found on cell surfaces, a tumor is identified as HER2 positive. About 25 percent of breast cancers are HER2 positive and may be treated with anti-HER2 medicines such as trastuzumab, or Herceptin. This targeted therapy blocks the growth of cancer cells.
Findings from past studies suggest that women diagnosed with breast cancer at a young age have an increased risk of cancer recurrence and death compared with women who are older when diagnosed. Yet, these earlier studies have not considered the HER2 status of the tumor or the use of anti-HER2 therapy.
Reason for the Study
Researchers wanted to find out if age at diagnosis influenced rates of early recurrence or death among women with early-stage, HER2-positive breast cancer.
They analyzed data from the HERA (Herceptin Adjuvant) trial that established the benefit of using trastuzumab to treat early-stage HER2-positive breast cancer. Trastuzumab had previously been shown to benefit women with HER2-positive metastatic disease.
The HERA trial consisted of 3,401 women with early-stage HER2-positive breast cancer who completed a course of chemotherapy. Women were randomized to receive either 1 year of trastuzumab or observation (no trastuzumab), with 1,703 women randomized to the trastuzumab group and 1,698 women assigned to the observation group.
Researchers of the current study divided these women into two groups based on age at diagnosis
- 21 percent were 40 or younger at diagnosis
- 79 percent were 41 or older at diagnosis
Data on rates of recurrence and death were evaluated after 2 years.
Regardless of which treatment group the women were assigned to, no significant differences were found between the younger and older age groups in
- disease-free survival, the time from study randomization to recurrence
- overall survival, the time from study randomization to death from any cause
Because of the short follow-up time (2 years), the researchers noted that they could only comment on risk of early disease recurrence or death.
Age at diagnosis was not strongly associated with risk of early breast cancer recurrence or death, and did not affect whether women benefited from trastuzumab. Further study is needed to assess whether age predicts later breast cancer recurrence or death.The researchers also suggested that future studies evaluate the impact of age at diagnosis on recurrence and death for breast cancer that is not HER2-positive.
What This Means for You
If you were 40 or younger when diagnosed with early-stage, HER2-positive breast cancer, this study may help reassure you that your
- age puts you at no greater risk for an early recurrence
- likelihood of benefiting from trastuzumab is not determined by your age
Talk with your oncologist and healthcare team about the medicines you are receiving or have received. Ask questions to understand your treatments and how they may help you.
You also may want to download or order a free copy of LBBC’s Guide to Understanding Treatment Decisions, for more information about targeted therapy and other treatments for HER2-positive breast cancer.
Partridge, AH, Gelber, S, Piccari-Gebhart, MJ et al. Effect of age on breast cancer outcomes in women with human epidermal growth factor receptor 2-positive breast cancer: Results from a Herceptin adjuvant trial. Journal of Clinical Oncology. 2013; doi: 10.1200/JCO.2012.44.1956.
This article was supported by Cooperative Agreement Number DP11-1111 from The Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention.