Some women with the most common type of breast cancer might safely skip chemotherapy. That’s the finding from a study presented at the American Society of Clinical Oncology meeting and published in the New England Journal of Medicine (Sparano et al, NEJM, June 3, 2018).
Which Women Might Safely Skip Chemotherapy?
Doctors have long known that some women diagnosed with breast cancer do well even if they don’t undergo chemotherapy. But they haven’t known how to identify those patients who could safely skip chemotherapy.
In this trial dubbed TAILORX, scientists conducted genetic testing (using the Oncotype DX test) on the tumors of more than 10,000 women. More than 6,000 of them had risk scores in the intermediate range between 11 and 25. All of the women in the study had tumors driven by estrogen and without the tumor protein HER2. Doctors could not detect any signs of breast cancer in their lymph nodes.
The Two Treatment Groups:
The investigators randomly assigned these volunteers to get anti-estrogen treatment alone (adjuvant endocrine therapy) or chemotherapy plus tamoxifen or other hormone blockers (chemoendocrine therapy). Women older than 50 and other women who scored 15 or less on the Oncotype DX test did as well with just hormone therapy as with chemo plus hormone therapy.
According to the investigators:
“At 9 years, the two treatment groups had similar rates of invasive disease–free survival…and overall survival (93.9% and 93.8%).”
These findings buttress previous findings that pointed in the same direction. Perhaps as many as 70,000 women in the US each year could skip chemotherapy treatment and its complications without compromising their survival.