In a nutshell
This study examined if the presence of certain genes had an effect on endocrine (hormone) treatment alone compared to chemoendocrine (chemotherapy and hormone) treatment for breast cancer. The study concluded that endocrine and chemoendocrine had the same effectiveness in women with certain genetic factors.
Some background
Breast cancer is associated with many genes that can affect how the cancer grows and responds to treatment. Genes can be measured by researchers using specific lab tests called an assay. The 21-gene assay can provide a recurrence score that may help to guide treatment. A higher score may indicate that chemotherapy may be helpful. It is not clear whether chemotherapy is as effective in patients with lower recurrence scores.
Methods & findings
9719 patients were included in the study. 6711 (69%) had a recurrence score (gene measurement) of 11 to 25. 1619 (17%) had a score of 10 or lower and 1389 (14%) had a recurrence score of 26 or higher. The mid-range group (11 to 25) were randomly assigned to receive either chemoendocrine therapy or just endocrine therapy alone. Chemotherapy treatments included docetaxel (Taxotere) -cyclophosphamide (Cytoxan) (56%), and anthracycline (anti-cancer drug taken from bacteria) treatment. Endocrine therapy included tamoxifen (Nolvadex) and an aromatase inhibitor (a drug which blocks formation of estrogen) or tamoxifen alone.
After 9 years, disease-free survival (alive with no recurrence of the breast cancer) was 83.3% for the endocrine-therapy group and 84.3% for the chemoendocrine group. The cancer did not spread to other parts of the body in 94.5% of the endocrine group and 95% of the chemoendocrine group. The overall survival rate was 93.9% in the endocrine group and 93.8% in the chemoendocrine group.
The bottom line
The study concluded that there was no difference in effectiveness between endocrine and chemoendocrine therapies in women with breast cancer of similar genetic factors.
The fine print
Discuss with your doctor about your treatment if you have been offered endocrine therapy or chemotherapy.
Published By :
The New England Journal of Medicine
Date :
Jun 04, 2018
