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Proffered paper session - Breast cancer, early stage

3849 - Distant disease-free survival (DDFS) according to response category in neoadjuvant endocrine therapy (NET): 6-Year analysis in phase III NEOS trial


19 Oct 2018


Proffered paper session - Breast cancer, early stage


Cytotoxic Therapy

Tumour Site

Breast Cancer


Hiroji Iwata


Annals of Oncology (2018) 29 (suppl_8): viii58-viii86. 10.1093/annonc/mdy270


H. Iwata1, N. Masuda2, Y. Yamamoto3, T. Fujisawa4, T. Toyama5, N. Taira6, M. Kashiwaba7, S. Ohtani8, T. Sakai9, Y. Hasegawa10, R. Nakamura11, H. Akabane12, Y. Shibahara13, H. Sasano13, T. Yamaguchi14, Y. Ohashi15

Author affiliations

  • 1 Breast Oncology, Aichi Cancer Center Hospital, 464-8681 - Nagoya/JP
  • 2 Surgery, NHO Osaka National Hospital, Osaka/JP
  • 3 Breast Surgery, Kumamoto University, Kumamoto/JP
  • 4 Breast Surgery, Gunma Prefectural Cancer Center, Gunma/JP
  • 5 Breast Surgery, Nagoya City University, 467-8601 - Nagoya/JP
  • 6 Breast Surgery, Okayama university hospital, Okayama/JP
  • 7 Breast Surgery, Sagara Hospital, Kagoshima/JP
  • 8 Breast Surgery, Hiroshima City Hospital, 730-0011 - Hiroshima/JP
  • 9 Surgical oncology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo/JP
  • 10 Breast Surgery, Hirosaki Municipal Hospital, Hirosaki/JP
  • 11 Breast Surgery, Chiba Cancer Center Hospital, 260-8717 - Chiba/JP
  • 12 Surgery, Hokkaido P.W.F.A.C. Asahikawa-Kosei General Hospital, Hokkaido/JP
  • 13 Pathology, Tohoku University Graduate School of Medicine, Sendai/JP
  • 14 Statisticus, Tohoku University Graduate School of Medicine, 980-8574 - Sendai/JP
  • 15 Integrated Science And Engineering For Sustainable Society, Chuo University, Tokyo/JP


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Abstract 3849


NEOS is a randomized phase III study that assessed the long-term prognosis of estrogen receptor positive (ER+) primary breast cancer (PBC) pts who received NET with/without adjuvant chemotherapy (CT). We presented the first report about the relationship between DFS and clinical response to NET at median follow-up 4Y in SABCS 2017. We now present new data corrected according to long follow-up (median 5.9Y).


Postmenopausal BC pts with ER +/HER2 negative, T1c-2, clinically node negative, and under 76 years old were enrolled at primary registration. Pts were treated by leterozole (LET) in weeks 24-28 after primary enrollment. Pts who experienced progression of disease (PD) during neoadjuvant phase were excluded at randomization and received systemic therapy driven by investigators before or after surgery. Pts who met eligibility criteria were randomized 1:1 to LET for 4.5-5 years after CT or LET alone for 4.5-5 years without CT after surgery. DFS/OS in patients showing CR, PR, SD or PD response to NET are secondary endpoints and DDFS is an exploratory endpoint.


Between May 2008 and June 2013, 904 patients were enrolled at primary registration from 100 institutions in Japan and 21 pts were withdrawn during neoadjuvant phase. The median age was 63 years, T1c: 36%, T2: 64%, and progesterone receptor (PgR) +: 79%. Clinical response rates (CR, PR, SD and PD) were 2% (16pts), 48% (421pts), 46% (403pts) and 5% (43pts), respectively. In each response, 0% (0/16), 10.7% (45/421), 12.7% (51/403), and 44.2% (19/43) experienced DFS events and 0% (0/16), 5.2% (22/421), 7.2% (29/403) and 26% (11/43) experienced DDFS events. DDFS in PD pts to NET were statistically significantly worse than CR, PR, SD pts (p < 0.001, hazard ratio 4.83 (95% CI:2.52-9.29). The predictive markers of PD for NET were PgR status (P < 0.001) and Ki67 status (P = 0.041) in biopsy specimen among factors evaluated by multivariate analysis


The DDFS of PBC pts excluding PD pts to NET is excellent regardless of treatment with/without CT. NET with utilization of PD response as a prognostic marker can be considered as a standard treatment option for these patients.

Clinical trial identification


Legal entity responsible for the study



The parent NEOS study was sponsored by CSPOR (Comprehensive Support Project for Oncology Research), part of a Sponsored by CSPOR and Novartis and Chugai Pharmaceuticals provided funding to CSPOR.

Editorial Acknowledgement


H. Iwata: Research: Chugai, Novartis, MSD, Lilly; Honororia: Chugai, AstraZeneca, Daiichi Sankyo; Advisory Board: Daiichi Sankyo, Chugai, Lilly, Kyowa Hakko Kirin, Pfizer, Novartis, AstraZeneca. N. Masuda: Honoraria: Chugai, AstraZeneca, Pfizer, Takeda; Research: Chugai, Novartis, MSD, Eli-Lilly, AstraZeneca, Daiichi Sankyo, Kyowa- Kirin, Pfizer. T. Toyama: Research fund: Eisai, Kyowa Kirin, Takeda, Chugai, Novartis, Nippon Kayaku, Pfizer, Daiichi Sankyo; Advisory board: AstraZeneca. M. Kashiwaba: Honoraria: Chugai, AstraZeneca. Y. Ohashi: Honororia: Chugai, PHRF; Consultant: Chugai; Research fund: Eisai. All other authors have declared no conflicts of interest.

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