Chemotherapy often is used after surgery to remove early-stage breast cancer to reduce the risk of breast cancer coming back (recurrence). This type of chemotherapy -- called adjuvant chemotherapy -- aims to weaken and destroy any cancer cells that may be left behind after surgery.
While chemotherapy after breast cancer surgery usually increases survival, a study has found that women older than 80 diagnosed with early-stage, hormone-receptor-negative breast cancer don’t get survival benefits from chemotherapy.
The study was published in the August 2015 issue of the Journal of the American Geriatrics Society. Read the abstract of “Comparative Effectiveness of Chemotherapy Regimens in Prolonging Survival for Two Large Population-Based Cohorts of Elderly Adults with Breast and Colon Cancer in 1992-2009.”
To do the study, the researchers looked in the SEER databases to find:
- women age 65 and older who were diagnosed with stage I to stage IIIA hormone-receptor-negative breast cancer (14,440 women)
- women and men age 65 and older diagnosed with stage III colon cancer (28,893 people)
SEER databases are large registries of cancer cases from sources throughout the United States maintained by the National Institutes of Health.
The researchers compared the outcomes of people who received chemotherapy to the outcomes of people who didn’t get chemotherapy.
Among the women diagnosed with breast cancer, chemotherapy after surgery reduced the risk of death from any cause by:
- 30% for women ages 65-69
- 26% for women ages 70-74
- 24% for women ages 75-79
But overall, for women ages 80-89, chemotherapy didn’t reduce the risk of dying from any cause. The only women ages 80-89 treated with chemotherapy who had better survival rates compared to women who didn’t get chemotherapy were women who were treated with the chemotherapy medicines Adriamycin (chemical name: doxorubicin) and Cytoxan (chemical name: cyclophosphamide).
In the people diagnosed with colon cancer, chemotherapy increased the chances of survival in all age groups.
It’s not clear why women older than 80 diagnosed with breast cancer didn’t get survival benefits from chemotherapy, except for women treated with the Adriamycin-Cytoxan combination.
“[It] could be due to several factors: tumors being less sensitive to chemotherapy, a decrease in dosage as the body gets weaker with age, or chemotherapy killing healthy cells in addition to cancer cells," said Xianglin Du, M.D., lead author of the study and professor of epidemiology, human genetics, and environmental sciences at the University of Texas Health Science Center at Houston.
If you’re older than 80 and have been diagnosed with early-stage, hormone-receptor-negative breast cancer, you may want to talk to your doctor about this study. If chemotherapy will be part of your treatment plan, it’s a good idea to ask your doctor which medicines are recommended for you and why. If Adriamycin and Cytoxan aren’t recommended for you, it’s especially important to find out why.