Scientists suggest that some early-stage breast cancer patients can scrap chemotherapy from their treatment, paving the way for a less painful method of recovery.
This is a breakthrough in cancer treatment as patients can potentially avoid the severe side effects of chemotherapy in the future.
The TailorX trials reveal that chemotherapy has no benefit as part of post-surgery in most patients (70 percent) afflicted with early-stage hormone receptor-positive, HER2-negative, axillary lymph node-negative breast cancer. It turns out that for this type of breast cancer, which is the most common, hormone therapy by itself is just as beneficial as hormone therapy with chemotherapy.
The study, included in the New England Journal of Medicine, was also presented at a meeting of the American Society of Clinical Oncology last June 3.
Lead author Joseph A. Sparano, M.D. explains in a statement that their findings confirm that the 21-gene expression test can be used to determine the recurrence risk, then potentially spare patients unnecessary and painful treatments if this test shows chemotherapy would be unbeneficial.
The Trials
The decade-long study included 10,273 women who had this specific type of early-stage breast cancer from 1,182 various sites in these following countries: Australia, New Zealand, Ireland, Peru, Canada, and the United States.
Key to the trials was a molecular test that assessed the expression of 21 genes associated with breast cancer recurrence. Each woman was given their risk score for recurrence at the ranges of low risk (0 to 10), intermediate risk (11 to 25), and high risk (26 to 100).
The women who got a low-risk score were given hormone therapy only, while the ones who logged a high-risk score had both hormone therapy and chemotherapy. The women with intermediate scores were randomly assigned to one of those two groups.
The Findings
Results show that the rates of these two groups were basically the same with a difference that's statistically insignificant.
After five years, the invasive disease-free survival rates of the two groups were nearly equal: 92.8 percent for the patients who only received hormone therapy and just 93.1 percent for the women who were also treated with chemotherapy. After nine years, it was still pretty much equal at 83.3 percent and then 84.3 percent, respectively.
These authors suggest that around 70 percent of the patients who have hormone receptor-positive, HER2-negative, node-negative breast cancer can actually opt out of chemotherapy.
One group do appear to benefit slightly with the addition of chemotherapy to post-surgery treatment: premenopausal women as well as women below 50 years old who had a higher rate within the intermediate risk range. It's unclear yet if the benefit can be attributed to the chemotherapy effects or to the endocrine suppression from chemo-induced menopause.
"Any woman with early-stage breast cancer 75 years or younger should have the 21-gene expression test and discuss the results with her doctor to guide her decision to the right therapy," Sparano advises.