Response to Induction Neoadjuvant Hormonal Therapy Using Upfront 21-Gene Breast Recurrence Score Assay-Results From...

Area of Science:

• Oncology
• Genomics
• Endocrinology

Background:

• Luminal, HER2-negative breast cancer is the most common subtype.
• Neoadjuvant chemotherapy is standard, but neoadjuvant hormone therapy (NAHT) benefits are unclear for select patients.

Purpose of the Study:

• Assess feasibility of upfront Oncotype DX assay for selecting operable luminal HER2-negative breast cancer patients for NAHT.
• Evaluate efficacy of induction NAHT in patients with recurrence score (RS) < 31.

Main Methods:

• Prospective, multicenter, international, double-blind, phase III SAFIA trial.
• Upfront Oncotype DX Breast Recurrence Score assay (RS < 31) to select patients for induction HT (fulvestrant +/- goserelin).
• Responding patients randomized to fulvestrant +/- goserelin + palbociclib or placebo.

Main Results:

• Feasibility of Oncotype DX assay on core biopsies was optimal in 96.4% of cases.
• 202 patients (78.3%) had RS < 31 and received induction NAHT.
• 93.4% of patients showed hormone sensitivity; no difference in NAHT efficacy across RS groups (0-10, 11-25, 26-30), but high RS (26-30) trended towards higher response (P=.05).

Conclusions:

• Upfront 21-gene assay on biopsies is feasible in the Middle-East and North Africa region.
• This method successfully selects patients with high hormone sensitivity (RS < 31) for NAHT.
• This approach offers an alternative to upfront surgery, minimizing progression risk, especially during pandemics.