WOMEN'S HEALTH
BREAST CANCER SUCCESS: De-escalate
Treatment for All? Not Yet
Beth Riley, MD, FACP
T
he death rate for breast cancer in the
US has steadily declined since the
mid-1990s. This is largely attribut-
able to a combination of increased
screening and better, more effective
targeted therapies. A better understanding of
disease biology has allowed for a de-escalation
of treatment chronicled in the lay and profes-
sional press. We no longer routinely perform an axillary dissection
with positive sentinel lymph nodes thus reducing the risk of lymph-
edema. Genomic tests help guide chemotherapy decision-making
in select women with estrogen positive breast cancer.
Oncotype DX is a 21-gene expression assay used routine-
ly in women with hormone receptor positive, human epidermal
growth factor receptor 2 (HER2)- negative, axillary node negative
breast cancer. Typically, patients are classified in one of three score
groups: low (<18), intermediate (18-31) or high (>31). Clinical
decision-making was well-defined for those who needed (high
score) or did not need (low score) chemotherapy, however data
for those in the intermediate category was less clear. The recent
TAILOR X trial broadened the cohort of women who could safely
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LOUISVILLE MEDICINE
forego chemotherapy and be treated with endocrine therapy alone.
This trial demonstrated that all women older than 50 years of age
with hormone receptor positive, HER2 negative, node negative
breast cancer and a recurrence score between 0-25 could forego
chemotherapy without an impact on recurrence. The lead authors
of the study noted that “when guided by the test, (chemotherapy)…
can be limited to the 30 percent whom we can predict will benefit
(1,2).” TAILOR X therefore translates to less therapy and less short
and long-term toxicity for the majority of women with early stage
hormone receptor positive, HER2 negative breast cancer without
compromising outcome. Based on the broad impact to women
across the US with early stage breast cancer, this was presented at
the plenary session during the 2018 American Society of Clinical
Oncology (ASCO) meeting in June.
Based on the number of women in the US these data affected,
this was also a favorite of the lay press highlighted in national papers
and the television nightly news. However, one important exception
was not well described in the lay press – the disparity in results for
women under the age of 50. In this cohort, there was a sustained
benefit for chemotherapy in those women with a mid-range score.
In women under the age of 50, only those with a low score (<11)