This study is a randomized, open-label, phase II trial designed to evaluate whether alternate-day dosing of letrozole preserves antiproliferative activity compared with standard daily dosing in postmenopausal women with estrogen receptor-positive, HER2-negative breast cancer.
Participants must have histologically confirmed breast cancer, clinical stage I-III as per the AJCC 8th edition (Anatomic Prognostic Staging).
Age ≥60 years
Age <60 years with ≥12 months of spontaneous amenorrhea without chemotherapy, endocrine therapy, ovarian suppression, pregnancy, or lactation
Prior bilateral oophorectomy
None
Parallel
Letrozole
DrugThis study is designed as a non-inferiority trial. Prior neoadjuvant endocrine therapy studies have demonstrated that short-term aromatase inhibitor therapy typically produces substantial reductions in tumor proliferation, with Ki-67 reductions of approximately 70-80% after several weeks of treatment.
Tumor proliferation measured by ki67
The primary endpoint is tumor proliferation measured by ki67 and will assess the log-transformed relative change in Ki-67 The mean log relative change will be compared between treatment arms using a linear regression model including treatment arm and the stratification factors.
Proportion of tumors achieving ≥50% reduction in Ki-67
The proportion of patients achieving at least a 50% reduction in Ki-67 will be summarized within each treatment group. Comparisons between groups will be performed using logistic regression models adjusting for stratification factors, and results will be reported as odds ratios with 95% confidence intervals.
Proportion of tumors with post-treatment Ki-67 ≤10%
The proportion of tumors with post-treatment Ki-67 ≤10% will be summarized within each treatment arm. Differences between groups will be evaluated using logistic regression models adjusting for stratification factors.
Change from baseline in circulating hormone levels- estradiol
Serum concentrations of estradiol will be measured using ultrasensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays. Hormone levels will be analyzed on the logarithmic scale. The log relative change in hormone levels between baseline and on-treatment measurements will be calculated and compared between treatment arms using linear regression models adjusting for stratification factors. Results will be presented as geometric mean ratios with 95% confidence intervals.
Change from baseline in circulating hormone levels- estrone
Serum concentrations of estrone will be measured using ultrasensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays. Hormone levels will be analyzed on the logarithmic scale. The log relative change in hormone levels between baseline and on-treatment measurements will be calculated and compared between treatment arms using linear regression models adjusting for stratification factors. Results will be presented as geometric mean ratios with 95% confidence intervals.
Click on the lead sponsor to view all of their trials.
This trial is not recruiting at the moment. You can still explore other options:
