Adjuvant S-1 plus endocrine therapy for ER-positive, HER2-negative, primary breast cancer: post-POTENT trial prognostic survey
This multicenter observational study investigated the prognosis of patients who participated in the Phase III POTENT trial, which examined combining S-1 with standard endocrine therapy in patients with estrogen receptor-positive, HER2-negative early breast cancer, over a longer follow-up period. The primary endpoint was overall survival (OS), with invasive disease-free survival (IDFS) and distant disease-free survival (DDFS) as secondary endpoints. Of the 1,930 POTENT trial participants, 1,593 patients (790 for S-1 and 803 for endocrine therapy alone) were included here. The median follow-up time was 77.5 months. Fifty-one and 58 deaths were observed in the S-1 and endocrine therapy alone groups, respectively. The 6-year OS rates were similar, with 94.4% in the S-1 group and 93.1% in the endocrine therapy alone group. Overall, both endocrine therapy alone and endocrine therapy plus S-1 resulted in favorable OS. Combining S-1 with endocrine therapy maintained the previously observed benefits of IDFS and DDFS.
Authors
- Tomoharu Sugie (ORCID: https://orcid.org/0000-0002-0712-7069)
- Takanori Ishida
- Shigeru Imoto (ORCID: https://orcid.org/0000-0002-0878-7851)
- Kenjiro Aogi (ORCID: https://orcid.org/0000-0001-8147-8062)
- Toshiaki Saeki (ORCID: https://orcid.org/0000-0002-8893-9519)
- Masahiro Takada (ORCID: https://orcid.org/0000-0002-5954-1296)
- Kenichi Watanabe
- Shinji Ohno (ORCID: https://orcid.org/0000-0003-2093-3353)
- Nobuaki Sato (ORCID: https://orcid.org/0000-0002-5171-085X)
- Takayuki Ueno (ORCID: https://orcid.org/0000-0002-9080-9377)
- Norikazu Masuda (ORCID: https://orcid.org/0000-0002-7302-0278)
- Hiroshi Ishiguro (ORCID: https://orcid.org/0000-0002-9859-5932)
- Masahiro Kitada (ORCID: https://orcid.org/0000-0002-9741-0510)
- Hiroji Iwata
- Rikiya Nakamura (ORCID: https://orcid.org/0000-0002-4349-9046)
- Masakazu Toi (ORCID: https://orcid.org/0000-0003-1488-9958)
- Yuichiro Kai
- Shin Takayama (ORCID: https://orcid.org/0000-0001-7210-0922)
- Yutaka Matsuyama (ORCID: https://orcid.org/0000-0003-2009-6831)
- Shigehira Saji
Institutions
- Kansai Medical University (JP)
- Fukushima Medical University (JP)
- Asahikawa Medical University (JP)
- Kyorin University (JP)
- Tohoku University (JP)
- Kyoto University (JP)
- Tokyo Metropolitan Komagome Hospital (JP)
- Nagoya City University (JP)
- Niigata Cancer Center Hospital (JP)
- National Hospital Organization Hokkaido Medical Center (JP)
- Chiba Cancer Center (JP)
- National Sagamihara Hospital (JP)
- Shikoku Cancer Center (JP)
- Oita University Hospital (JP)
- Tokyo National Hospital (JP)
- Japanese Foundation For Cancer Research (JP)
- Nagoya University (JP)
- The University of Tokyo (JP)
- Saitama Medical University (JP)
Publication Details
- Journal
- npj Breast Cancer
- Published
- 2025-10-24
- DOI
- https://doi.org/10.1038/s41523-025-00832-w
- Primary Topic
- Advanced Breast Cancer Therapies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Pitt Hopkins Research Foundation
- Taiho Pharmaceutical