Developing anemia during chemotherapy to treat early-stage breast cancer seems to affect the risk of the cancer coming back. A small study found that women who became anemic while getting chemotherapy after early-stage breast cancer surgery were more than twice as likely to have the cancer come back 5 years after surgery compared to women who didn't develop anemia. Almost 20% of the women with chemotherapy-related anemia had the cancer come back 5 years after surgery compared to only 8.9% of the women who didn't develop anemia.
Many women in the study were followed for more than 5 years. The researchers found that the women in the study who developed anemia had a risk of the cancer coming back at any time (including longer than 5 years after surgery) that was almost 3 times greater than the women who didn't develop anemia.
Although the risk of the cancer coming back in the breast was different, the researchers found that the risk of the cancer coming back in another place in the body (metastatic cancer) was the same for women who did and didn't develop anemia. Also, the risk of dying from breast cancer was the same for women who did and didn't develop anemia.
Chemotherapy is commonly used after early-stage breast cancer surgery to lower the risk of the cancer coming back. Anemia is a common side effect of chemotherapy, but not all women who get chemotherapy develop anemia. Radiation therapy is also used to lower the risk of the cancer coming back when a woman has lumpectomy instead of mastectomy. In addition to chemotherapy, the women in this study got radiation therapy if they had lumpectomy.
The researchers aren't sure why the women who developed chemotherapy-related anemia were more likely to have the cancer come back.
Doctors sometimes use medicines to prevent or treat chemotherapy-related anemia. This research didn't look at whether these medications could lower the risk of the cancer coming back. Even with these medicines, many women will still develop some level of anemia, which could affect their risk of the cancer coming back.
If you're getting chemotherapy after surgery as part of your treatment plan for early-stage breast cancer, talk to your doctor about anemia and steps you can take to lower both the risk of anemia and the cancer coming back. Visit the breastcancer.org Chemotherapy section to learn more about chemotherapy and its side effects.