Recruiting
Impact of Endocrine Therapy, Menstrual Cycle, PAM50, Ki67 on Treatment Decisions in HR+ and HER2- Breast Cancer
PEAK is a prospective, multicenter, non-interventional investigator-initiated trial (IIT) that aims to investigate the influence of the menstrual cycle phase on Ki67 in patients who either receive Tamoxifen, Aromatase inhibitors ± gonadotropin-releasing hormone (GnRH)-Analogues or nothing or no preoperative endocrine treatment as part of the clinical routine. The investigators moreover address the question whether PAM50 assessment in addition to Ki67 dynamics still impacts treatment recommendations.
ClinicalTrials.gov IDNCT05878314
PhaseNot Applicable
Enrollment504
SponsorUniversity Hospital Tuebingen
Age18 Years and older
SexFEMALE
About this study
PEAK is a prospective, multicenter, non-interventional investigator-initiated trial (IIT) that aims to investigate the influence of the menstrual cycle phase on Ki67 in patients who either receive Tamoxifen, Aromatase inhibitors ± gonadotropin-releasing hormone (GnRH)-Analogues or nothing or no preoperative endocrine treatment as part of the clinical routine. The investigators moreover address the question whether PAM50 assessment in addition to Ki67 dynamics still impacts treatment recommendations.
Primary outcomes
- Influence of the menstrual cycle on initial Ki67 in premenopausal women (duration of therapy and follow-up data (10 years))
Eligibility information
Inclusion Criteria:
* women ≥ 18 years of age
* histologically proven unilateral primary non-metastatic invasive breast cancer
* Estrogen receptor (ER)-/ or Progesterone receptor (PR)- positive and HER2-negative
* Ki67 from core biopsy is available
* no lymph-node involvement by clinical evaluation and ultrasound (cN0)
* not amendable to neoadjuvant chemotherapy
* surgery or planned surgery at the Department for Women's Health, Tuebingen or Freiburg
* planned preoperative endocrine treatment with Tamoxifen, Aromatase inhibitors, Goserelin or nothing for 2 - 4 weeks
* written informed consent
Exclusion Criteria:
* ER-negative and PR-negative
* HER2-positive
* bilateral breast cancer
* preexisting cancer disease within the last 10 years
* preexisting invasive ipsi- or contralateral breast cancer (non-invasive ipsi- or contralateral breast cancer is not regarded as an exclusion criteria)
* any systemic breast cancer therapy before inclusion into the trial
* indication for neoadjuvant chemotherapy
* any systemic therapy except Tamoxifen, Aromatase inhibitors, Goserelin before surgery
* locally advanced, inoperable or metastatic breast cancer
* pregnant or lactating patients
* inadequate general condition (not fit for chemotherapy)
* hormonal contraception within 6 months before inclusion
Study locations
- Department of Women's Health, Tübingen, 72076 Germany
Before you participate: Varda Clinical is an independent discovery tool, not the study sponsor or a medical provider. Eligibility can only be determined by the official study team. Discuss potential risks and benefits with a qualified healthcare professional.
Source: ClinicalTrials.gov. Record last refreshed by Varda Clinical: 2026-10-13.