A study published in June, 2018, in the New England Journal of Medicine may change the guidelines on how doctors treat a common form of breast cancer. According to the report, about 70% of people in early stages of certain breast cancers can be treated just as effectively without chemotherapy.
The researchers focused on patients with hormone-receptor positive, HER2-negative, node-negative breast cancer. This means the tumors test positive for estrogen receptors, test negative for the HER2 gene, and have not spread to the lymph nodes. About 50% of women with breast cancer fall into this group.
The new study took a careful look at patients who were within the mid-range risk of their cancers recurring after treatment. About half were treated solely with hormone therapy, and the rest were given an added chemotherapy agent. In follow-up, the hormone therapy group had a 93.9% survival rate—compared to a survival rate of 93.8% for the combined treatments. Of the survivors, 83.3% of the hormone-only group remained disease-free after nine years, compared to 84.3% of those who also underwent chemotherapy.
Risks Versus Benefits
Chemotherapy saves lives, but it can also kill. A 2016 analysis looked at the first 30 days of chemotherapy treatment in over 23,000 U.K. breast cancer patients. In those first 30 days, 569 severely ill breast cancer patients died - these patients were being treated to relieve symptoms and improve quality of life, curing the cancer was not expected. However, another 41 breast cancer patients died and these patients were treated with chemotherapy where the intent was to cure the cancer.
Chemotherapy side effects can include hair loss, diarrhea, fatigue, memory loss, anemia, impaired immune function, osteoporosis, and vision problems. Given these side effects and other dangers of chemotherapy, it’s understandable why many researchers and patients consider reserving such treatments for cases that stand little chance of survival without it. In many cases of breast cancer, the benefits might not outweigh the risks—and chemotherapy may even be unnecessary. But let's remember that chemotherapy is still recommended for those diagnosed with later stages of the disease.
The Future of Breast Cancer Treatment
This new strategy uses genetic testing to determine how dependent a cancer is on hormones, looking at 21 different genes and the roles they play in cancer progression. Genetic testing allows doctors to make more informed treatment decisions, and can also open up new avenues for treatment options.