Potential prognostic value of the free T3/T4 ratio in HR+/HER2 - metastatic breast cancer treated with CDK4/6 inhibitors.
- 1Department of Medical Oncology, Hacettepe University Cancer Institute, Mehmet Akif Ersoy Sk. 19 A, Altindag, Ankara, 06230, Turkey. [email protected].
- 2Department of Medical Oncology, Hacettepe University Cancer Institute, Mehmet Akif Ersoy Sk. 19 A, Altindag, Ankara, 06230, Turkey.
- 3Department of Internal Medicine, Hacettepe University Faculty of Medicine, Ankara, Turkey.
Abstract
Purpose
The free triiodothyronine (fT3)/free thyroxine (fT4) ratio is an index estimating the peripheral activity of thyroid hormones. The prognostic role of the fT3/fT4 ratio in colorectal cancer, urothelial cancer, renal carcinoma, and lymphoma is well-recognized, but its effect in metastatic breast cancer remains unestablished.Methods
We conducted a retrospective study of metastatic breast cancer patients treated with cyclin-dependent kinase (CDK) 4/6 inhibitors at Hacettepe University Hospital. Baseline fT3 and fT4 levels were recorded, and patients were categorized into two groups based on the median fT3/fT4 ratio: Low and High fT3/fT4 Ratio Groups.Results
We included 162 h-positive/HER2-negative metastatic breast cancer patients. There were no significant differences between the Low and High fT3/fT4 Ratio Groups in terms of age, sex, tumor grade, histopathologic type, menopausal status, sites of metastases, lines of treatment prior to CDK4/6 inhibitors, type of CDK4/6 inhibitor, or endocrine backbone therapy. Of all patients, 47 (29.2%) received two or more lines of treatment before initiating CDK4/6 inhibitors. High fT3/fT4 ratios were associated with significantly longer progression-free survival (PFS) compared to Low fT3/fT4 ratios (median, 9.7 vs. 6.9 months; HR: 0.68; 95% CI: 0.47-0.97; p = 0.035) and significantly longer overall survival (OS) compared to Low fT3/fT4 ratios (median, NR vs. NR months; HR: 0.30; 95% CI: 0.15-0.60; p < 0.001).Conclusions
Our study showed that high fT3/fT4 ratios were independent factors associated with longer PFS and OS in metastatic breast cancer patients treated with CDK4/6 inhibitors, supporting the role of high fT3/fT4 ratios as a prognostic marker.
Related
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- Prognostic Value of Metabolic–Muscle Reserve Index in HR+/HER2− Metastatic Breast Cancer Treated with CDK4/6 Inhibitors
- Relationship between overall survival and progression-free survival with 18 F-FDG PET/CT metabolic parameters in metastatic breast cancer patients treated with CDK 4/6 inhibitors
- CT-defined sarcopenia and outcomes in HR+/HER2− metastatic breast cancer treated with CDK4/6 inhibitors
- Recursive partitioning analysis model based on ¹⁸F-FDG PET/CT metabolic parameters for recurrent or metastatic nasopharyngeal carcinoma treated with PD-1 inhibitors and chemotherapy.
BibTeX
@article{kavgaci2026potential,
title = {{Potential prognostic value of the free T3/T4 ratio in HR+/HER2 - metastatic breast cancer treated with CDK4/6 inhibitors.}},
author = {Gozde Kavgaci and Taha Koray Sahin and Naciye Guduk and Fırat Sirvan and Deniz Can Guven and Sercan Aksoy},
journal = {BMC cancer},
year = {2026},
month = aug,
doi = {10.1186/s12885-026-16756-y},
url = {https://europepmc.org/article/MED/43009831},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Potential prognostic value of the free T3/T4 ratio in HR+/HER2 - metastatic breast cancer treated with CDK4/6 inhibitors.
AU - Gozde Kavgaci
AU - Taha Koray Sahin
AU - Naciye Guduk
AU - Fırat Sirvan
AU - Deniz Can Guven
AU - Sercan Aksoy
PY - 2026
DA - 2026/08/14
JO - BMC cancer
DO - 10.1186/s12885-026-16756-y
UR - https://europepmc.org/article/MED/43009831
AB - Purpose The free triiodothyronine (fT3)/free thyroxine (fT4) ratio is an index estimating the peripheral activity of thyroid hormones. The prognostic role of the fT3/fT4 ratio in colorectal cancer, urothelial cancer, renal carcinoma, and lymphoma is well-recognized, but its effect in metastatic breast cancer remains unestablished.Methods We conducted a retrospective study of metastatic breast cancer patients treated with cyclin-dependent kinase (CDK) 4/6 inhibitors at Hacettepe University Hospital. Baseline fT3 and fT4 levels were recorded, and patients were categorized into two groups based on the median fT3/fT4 ratio: Low and High fT3/fT4 Ratio Groups.Results We included 162 h-positive/HER2-negative metastatic breast cancer patients. There were no significant differences between the Low and High fT3/fT4 Ratio Groups in terms of age, sex, tumor grade, histopathologic type, menopausal status, sites of metastases, lines of treatment prior to CDK4/6 inhibitors, type of CDK4/6 inhibitor, or endocrine backbone therapy. Of all patients, 47 (29.2%) received two or more lines of treatment before initiating CDK4/6 inhibitors. High fT3/fT4 ratios were associated with significantly longer progression-free survival (PFS) compared to Low fT3/fT4 ratios (median, 9.7 vs. 6.9 months; HR: 0.68; 95% CI: 0.47-0.97; p = 0.035) and significantly longer overall survival (OS) compared to Low fT3/fT4 ratios (median, NR vs. NR months; HR: 0.30; 95% CI: 0.15-0.60; p < 0.001).Conclusions Our study showed that high fT3/fT4 ratios were independent factors associated with longer PFS and OS in metastatic breast cancer patients treated with CDK4/6 inhibitors, supporting the role of high fT3/fT4 ratios as a prognostic marker.
SN - 1471-2407
ER -