Having surgery along with systemic treatments or with systemic treatments and radiation therapy can improve survival for women diagnosed with metastatic hormone-receptor-positive or HER2-positive breast cancer, a study suggests.
The research was published online on Oct. 30, 2020, by the Annals of Surgical Oncology. Read the abstract of "Benefits of Surgical Treatment of Stage IV Breast Cancer for Patients With Known Hormone Receptor and HER2 Status."
Metastatic breast cancer (also called stage IV) is cancer that has spread to parts of the body away from the breast, such as the bones or liver.
Systemic treatments are treatments that affect the whole body by going through the bloodstream. Chemotherapy medicines, hormonal therapy medicines, targeted therapy medicines, and immunotherapy medicines are examples of systemic treatments.
Treatments for metastatic breast cancer
Systemic treatments are the standard of care for people diagnosed with metastatic breast cancer.
Surgery is recommended for some people with metastatic breast cancer, in most cases to relieve pain or other symptoms.
Studies have looked at whether surgery can improve survival for people diagnosed with metastatic breast cancer, but the results have been mixed. Still, none of the earlier studies took into account the hormone receptor status or the HER2 status of the breast cancer or whether giving chemotherapy before or after surgery affected survival.
So a group of researchers wanted to do another study taking those three factors into account.
"Results from previous trials evaluating surgical benefit in metastatic breast cancer patients have been questioned because of the small number of participants or the fact that patients weren't also receiving chemotherapy or other systemic therapies," Kelly Stahl, M.D., lead author and surgical resident at the Penn State College of Medicine, said in a statement. "We felt another key factor missing from those studies was whether the biologic subtype of breast cancer affected the survival rates in relation to surgical intervention."
About this study
This study was a retrospective study. Retrospective means the researchers looked at information collected in the past, before the study was done.
The study included 12,838 women diagnosed with metastatic breast cancer between 2010 and 2015. All the information came from the National Cancer Database, a collection of information on about 70% of newly diagnosed cancer cases maintained by the American Cancer Society and the American College of Surgeons. The information in the database comes from nearly 1,500 Commission on Cancer-accredited programs.
All the women lived longer than 6 months after being diagnosed with metastatic breast cancer, and all received systemic treatment.
- 6,649 received systemic treatment alone
- 2,906 received systemic treatment and radiation therapy
- 1,689 received systemic treatment and surgery
- 1,594 received systemic treatment, surgery, and radiation therapy
The researchers analyzed the 5-year overall survival rates of the various treatment groups.
Overall survival is how long a person lives, whether or not the cancer grows.
The researchers found that women who were treated with surgery had better survival rates than women who did not have surgery. Five-year overall survival rates were:
- 38% for women who received systemic treatment, surgery, and radiation therapy
- 32% for women who received systemic treatment and surgery
- 21% for women who received systemic treatment alone
- 19% for women who received systemic treatment and radiation therapy
For the 931 women diagnosed with metastatic HER2-positive breast cancer, women who had surgery had better survival than women who didn’t have surgery. Five-year overall survival rates for women with HER2-positive disease were:
- 48% for women who received systemic treatment, surgery, and radiation therapy
- 41% for women who received systemic treatment and surgery
- 29% for women who received systemic treatment alone
- 21% for women who received systemic treatment and radiation therapy
The researchers noted that the overall survival rates for women diagnosed with metastatic HER2-positive breast cancer were higher than they were for all the women in the study, no matter the treatment regimen they received.
For the 3,283 women who were treated with surgery, the researchers looked to see if the timing of chemotherapy in relation to surgery affected survival rates, taking into account hormone receptor status and HER2 status.
For women diagnosed with HER2-positive metastatic breast cancer, chemotherapy before surgery, called neoadjuvant chemotherapy by doctors, was linked to better survival compared to chemotherapy after surgery, called adjuvant chemotherapy by doctors. Five-year overall survival rates for women diagnosed with HER2-positive metastatic breast cancer were:
- 55% for women treated with neoadjuvant chemotherapy
- 35% for women treated with adjuvant chemotherapy
For women diagnosed with hormone-receptor-positive metastatic breast cancer, neoadjuvant chemotherapy also was linked to better survival. Five-year overall survival rates were:
- 42% for women diagnosed with estrogen-receptor-positive disease treated with neoadjuvant chemotherapy
- 30% for women diagnosed with estrogen-receptor-positive disease treated with adjuvant chemotherapy
- 45% for women diagnosed with progesterone-receptor-positive disease treated with neoadjuvant chemotherapy
- 32% for women diagnosed with progesterone-receptor-positive disease treated with adjuvant chemotherapy
"Not only did we find that surgery may be beneficial for treatment-responsive metastatic breast cancer patients, we also uncovered that getting chemotherapy before that surgery had the greatest survival advantage in patients with positive HER2 and estrogen and progesterone receptor status," said Chan Shen, Ph.D., associate professor of surgery at Penn State.
What this means for you
While the results of this study are very encouraging, it’s important to remember that this was a retrospective study, so the data were collected before the study was done. Many researchers feel a retrospective study is not as strong as a prospective study, where the study is designed and then the data are collected.
Still, if you’ve been diagnosed with metastatic breast cancer, especially HER2-positive or hormone-receptor-positive disease, and surgery isn’t recommended for you, you may want to bring up this study and talk to your doctor about why surgery isn’t in your treatment plan. If you do decide to have surgery, you also may want to talk to your doctor about the timing of chemotherapy. This study suggests that having chemotherapy before surgery for metastatic HER2-positive or hormone-receptor-positive breast cancer offers more survival benefits than having chemotherapy after surgery.
Together, you and your doctor will develop the best treatment plan for your unique situation.
For more information on metastatic breast cancer treatments, visit the Breastcancer.org Metastatic Breast Cancer pages.
To talk with others who have been diagnosed with metastatic breast cancer, join the Breastcancer.org Discussion Board forum Stage IV/Metastatic Breast Cancer ONLY.
Written by: Jamie DePolo, senior editor
Reviewed by: Brian Wojciechowski, M.D., medical adviser
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