Treatments given to weaken and destroy breast cancer before surgery are called neoadjuvant treatments. Most neoadjuvant treatments involve one or more chemotherapy medicines. Targeted therapy medicines, hormonal therapy, or radiation therapy also are sometimes used as neoadjuvant treatments.
Treatment before surgery isn’t routinely used to treat early-stage breast cancer, but may be used if the cancer is large or aggressive. When neoadjuvant treatment dramatically shrinks a cancer, lumpectomy instead of mastectomy may be an option for some women.
A study has found that neoadjuvant hormonal therapy seems to be as effective as neoadjuvant chemotherapy for early-stage, hormone-receptor-positive breast cancer and causes fewer side effects.
The study was published in the November 2016 issue of JAMA Oncology. Read the abstract of “Neoadjuvant Endocrine Therapy for Estrogen Receptor-Positive Breast Cancer: A Systematic Review and Meta-analysis.”
There are several types of hormonal therapy medicines. Tamoxifen, a selective estrogen receptor modulator (SERM), is one of the most well-known. Tamoxifen can be used to treat both premenopausal and postmenopausal women. In early the 2000s, the aromatase inhibitors:
- Arimidex (chemical name: anastrozole)
- Aromasin (chemical name: exemestane)
- Femara (chemical name: letrozole)
were shown to be more effective after surgery in postmenopausal women and are now used more often than tamoxifen to treat women who’ve gone through menopause.
"Estrogen-receptor-positive tumors are generally highly receptive to endocrine therapy with drugs such as tamoxifen [or the] aromatase inhibitors," said Aditya Bardia, M.D., assistant professor of medicine at Harvard Medical School and senior author of the study. "But while endocrine therapy is the most important component of adjuvant or postsurgical therapy, use of neoadjuvant endocrine therapy has been low in the U.S. Since the chemotherapy more commonly used in this situation might not be the best option for patients with these tumors, we conducted a comprehensive, systematic review and meta-analysis to evaluate rigorously the existing scientific evidence."
This study was a meta-analysis -- a study that combines and analyzes the results of many earlier studies. In this case, the results of 3,490 women in 20 studies that started in 2015 or earlier were analyzed. All the women had been diagnosed with early-stage, hormone-receptor-positive breast cancer and treated with either hormonal therapy or chemotherapy before surgery.
Besides comparing the effectiveness of chemotherapy and hormonal therapy before surgery, the researchers also looked at whether different types of hormonal therapy offered different results.
The researchers found that neoadjuvant hormonal therapy seemed as effective as neoadjuvant chemotherapy in treating early-stage, hormone-receptor-positive disease:
- The percentage of women who had the cancer shrink or remain stable was about the same in both treatment groups.
- The percentage of women who were able to have lumpectomy instead of mastectomy was about the same in both groups.
But the women who were treated with neoadjuvant hormonal therapy had fewer serious side effects.
The researchers also found that a neoadjuvant aromatase inhibitor was more effective than neoadjuvant tamoxifen.
"Endocrine therapy is an approved option for neoadjuvant treatment of [early-stage] estrogen-receptor-positive breast cancer, so there's no reason our findings cannot be applied to treatment right now," said Laura Spring, M.D., the study’s lead author and a senior oncology fellow at the Massachusetts General Hospital Cancer Center. "With the spurt in development of new targeted therapies, particularly CDK4/6 inhibitors, more research is needed to look at combining endocrine therapy with those drugs for neoadjuvant treatment."
If you’ve been diagnosed with early-stage, hormone-receptor-positive breast cancer and your doctor has recommended treatment before surgery, you may want to ask your doctor about this study. Ask why one treatment is recommended over another, as well as the risks and benefits of each treatment option. Together, you and your doctor can make the best decision for your unique situation.