Prediction of response to neoadjuvant hormonal therapy (NAHT) using upfront oncotype Dx recurrence score (RS): Results from the SAFIA phase III trial.
Khalid Alsaleh, A. Bounedjar, Mohammed Oukkal, Hasen Mahfouf, Kamel Bouzid, A. Bensalem, Prof Taha Fillali, B. Larbaoui, Alaa Kandil, Meteb Al‐Foheidi, Hassan Errihani, Marwan Ghosn, Nashwa A. Abdulaziz, Farida Dabouz, M.R.K. Bahadoor, Heba Mohamed El Zawahry, Sherif A Kullab, Jean-Marc A. Nabholtz
Abstract
594 Background: While hormonal therapy (HT) is a fundamental treatment in breast cancer therapy, neoadjuvant NAHT is not considered standard. The SAFIA trial is a prospective international neoadjuvant Phase III investigating the potential role of the addition of palbociclib (P) in patients (pts) sensitive to HT. We report the results of induction Faslodex (+/- zoladex) in pts initially selected by RS < 31, in order to assess their individual HT sensitivity before double-blind randomization HT vs HT + P followed by surgery. Materials and Methods: A total of 308 pts (stages II and IIIA Luminal A/B HER2 negative) in 24 centers and 6 countries (Middle-East/Maghreb) underwent upfront RS to select pts for induction HT. Pts with RS < 31 received induction neoadjuvant fulvestrant (500 mg i.m Day 1, 14, 28 then q.4 weeks) + goseriline (3.6 mg s.c q.4 w for pre and peri-menopausal pts) for 4 months, followed by clinical and radiological assessment of the disease response before randomization. Response was defined as no progression: Complete Response-CR/ Partial Response-PR: > 50% and Minor Response-MR: < 50% to > 0%/ No Response-NR: progression > 0%. Results: A total of 70 pts (22%) with RS > 31 were excluded, leaving 238 eligible pts for NAHT, age (25-84); pre-peri/ post menopause: 135 (57%)/103 (43%); Luminal A/B: 112 (49%)/114 (51%); Stage II/IIIA: 196 (87%) / 29 (13%). One hundred and seventy-seven pts (177) have validated responses to induction NAHT: CR: 9 pts (5%) / MR: 105 pts (59%) for major response rate: 64% / MR: 56 pts (32%) / NR: 7 pts (4%); available RS 0-10: 23 pts (16%) / RS 11-18: 67 pts (47%) / RS 19-25: 34 pts (24%) / RS 26-30: 18 pts (13%). Correlations between Response to NAHT and RS are shown in the table below (not statistically significant). Conclusions: In our population, upfront Oncotype DX RS < 31 allowed to select pts for induction NAHT without loss of chances with a no-progression rate (CR+PR = MR) of 96%. No significant correlation was found between RS and response to NAHT. Upfront RS > 31 (22%) is selecting pts candidates for neoadjuvant chemotherapy with a potential high risk of endocrine resistance. Clinical trial information: ICRG1201 .