Effect of low-dose tamoxifen on benign gynecological and breast conditions in a phase 3 trial in noninvasive breast cancer
Despite the proven efficacy of tamoxifen (T) in breast cancer prevention, its uptake remains limited due to concerns over side effects. A phase III trial showed that low-dose T (5 mg/day for 3 years) significantly reduces recurrence with minimal toxicity. After 10 years of follow-up, we observed no significant differences in benign gynecological or breast events between the tamoxifen and placebo (P) arms. The uterus was the most frequently affected site (30 cases per arm), followed by the breast (18) and ovary (5 vs 3 on T and P, respectively). Endometrial polyps were similarly distributed. Endometrial thickness remained stable in premenopausal women and showed only a mild, non-clinically significant increase in postmenopausal women on T (∼1.5 mm). Compared with data on standard-dose tamoxifen, rates of benign events were lower. These findings reinforce the favorable safety profile of low-dose tamoxifen. ClinicalTrials.gov: NCT01357772.
Authors
- Katia Cagossi
- Matteo Puntoni (ORCID: https://orcid.org/0000-0002-7908-0626)
- Francesco Millo
- Davide Serrano (ORCID: https://orcid.org/0000-0002-2945-4108)
- Elisa Gallerani (ORCID: https://orcid.org/0000-0001-9394-8535)
- Matteo Lazzeroni (ORCID: https://orcid.org/0000-0002-2162-4002)
- Patrizia Serra (ORCID: https://orcid.org/0000-0003-4959-579X)
- Laura Cortesi (ORCID: https://orcid.org/0000-0001-8950-8561)
- Irene Maria Briata (ORCID: https://orcid.org/0000-0003-0767-0026)
- Aliana Guerrieri‐Gonzaga (ORCID: https://orcid.org/0000-0003-1915-1688)
- Andrea DeCensi (ORCID: https://orcid.org/0000-0003-2635-4491)
- Martino Oliva
- Bernardo Bonanni (ORCID: https://orcid.org/0000-0003-3589-2128)
- Alessio Carbone (ORCID: https://orcid.org/0009-0008-9907-3299)
- Giuseppe Aprile
- Maria Digennaro (ORCID: https://orcid.org/0000-0001-7189-6893)
- Livia Giordano (ORCID: https://orcid.org/0000-0002-9525-6070)
Institutions
- University of Parma (IT)
- Ente Ospedaliero Ospedali Galliera (IT)
- Azienda Ospedaliera Citta' della Salute e della Scienza di Torino (IT)
- Departamento de Epidemiología (GT)
- Istituto Ramazzini (IT)
- Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IT)
- Azienda Ospedaliero Universitaria Ospedali Riuniti (IT)
- Azienda Ospedaliero-Universitaria di Modena (IT)
- University Hospitals Parma Medical Center (US)
- Azienda Socio Sanitaria Territoriale Lariana (IT)
- Istituto Tumori Bari (IT)
- Ospedale San Bortolo (IT)
- Aziende Socio Sanitarie Territoriale dei Sette Laghi
- European Institute of Oncology (IT)
Publication Details
- Journal
- JNCI Journal of the National Cancer Institute
- Published
- 2025-08-29
- DOI
- https://doi.org/10.1093/jnci/djaf250
- Citations
- 1
- Primary Topic
- Estrogen and related hormone effects
- Type
- article
- Field-Weighted Citation Impact
- 1.82