Endocrine therapy with accelerated Partial breast irradiatiOn or exclusive ultra-accelerated
Partial breast irradiation for women aged ≥ 60 years with Early-stage breast cancer
(EPOPE)
Breast cancer in the elderly has become a public health concern; there is a need to
re-design its treatment with a view to de-escalation. Our paper sets out the rationale
for a phase 3 randomized trial to evaluate less burdensome adjuvant procedures that
remain effective and efficient.For low-risk breast cancer in the elderly, adjuvant
treatment has been adjusted in order to make it more suitable and efficient. Hypofractionated
radiation therapy based on accelerated or non-accelerated regimens as well as accelerated
and ultra-accelerated partial breast irradiation (APBI) protocols were reviewed. Withdrawal
of radiation (RT) or endocrine therapies (ET) from the adjuvant procedure were also
investigated. Based on molecular and APBI classifications, inclusion criteria were
discussed.Phase 3 randomized trials which compared standard vs. accelerated/non-accelerated
hypofractionated regimens confirmed that the latter were non-inferior in terms of
local control. Similarly, except for intraoperative-based techniques, APBI achieved
non-inferior local control rates compared to whole breast irradiation for low-risk
breast cancer. In phase 2 prospective trials using ultra APBI, encouraging results
were observed regarding oncological outcome and toxicity profile. In phase 3 trials,
adjuvant ET without RT significantly increased the rate of local relapse with no impact
on overall survival while RT alone proved effective. Elderly patients aged 60 or more
with low-risk, luminal A breast cancer were chosen as the target population in a phase
3 randomized trial comparing APBI + 5-year ET vs. uAPBI (16 Gy 1f) alone.To investigate
de-escalation adjuvant treatment for elderly breast cancer patients, we have defined
a road map for testing more convenient strategies. This EPOPE phase 3 randomized trial
is supported by the GEC-ESTRO breast cancer working group.
