A surprising complete radiographic response to palbociclib plus endocrine therapy in an HR-positive, HER2-low lung, pleural, and lymph node metastatic breast cancer patient: a case report.
- 1Department of Breast Surgery, Pingxiang People's Hospital, Pingxiang, Jiangxi, China.
- 2Department of Pathology, Pingxiang People's Hospital, Pingxiang, Jiangxi, China.
Abstract
Hormone receptor-positive, human epidermal growth factor receptor 2-low (HER2-low) metastatic breast cancer (MBC) constitutes the predominant subtype of advanced breast cancer, with most patients eventually developing resistance to endocrine therapy (ET) and cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). This case report describes a 64-year-old woman with hormone receptor (HR)-positive, HER2-low MBC involving lung, pleural, and lymph node metastases who achieved a remarkable and sustained radiographic complete response (rCR) to palbociclib plus fulvestrant, followed by letrozole after fulvestrant injection intolerance. The patient exhibited near-complete regression of metastatic lesions within 18 months and maintained remission for over 6 years, far exceeding the typical median progression-free survival observed in clinical trials. The prolonged remission observed underscores the existence of biologically distinct tumor subsets with exceptional sensitivity to CDK4/6 inhibition, warranting investigation into underlying molecular mechanisms.
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BibTeX
@article{cha2026surprising,
title = {{A surprising complete radiographic response to palbociclib plus endocrine therapy in an HR-positive, HER2-low lung, pleural, and lymph node metastatic breast cancer patient: a case report.}},
author = {Mingzhi Cha and Hao Yi and HuiMing Li and Rongrong Peng},
journal = {Frontiers in oncology},
year = {2026},
month = oct,
doi = {10.3389/fonc.2026.1856673},
url = {https://europepmc.org/article/MED/42908516},
note = {CC BY},
}
RIS
TY - JOUR
TI - A surprising complete radiographic response to palbociclib plus endocrine therapy in an HR-positive, HER2-low lung, pleural, and lymph node metastatic breast cancer patient: a case report.
AU - Mingzhi Cha
AU - Hao Yi
AU - HuiMing Li
AU - Rongrong Peng
PY - 2026
DA - 2026/10/07
JO - Frontiers in oncology
DO - 10.3389/fonc.2026.1856673
UR - https://europepmc.org/article/MED/42908516
AB - Hormone receptor-positive, human epidermal growth factor receptor 2-low (HER2-low) metastatic breast cancer (MBC) constitutes the predominant subtype of advanced breast cancer, with most patients eventually developing resistance to endocrine therapy (ET) and cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). This case report describes a 64-year-old woman with hormone receptor (HR)-positive, HER2-low MBC involving lung, pleural, and lymph node metastases who achieved a remarkable and sustained radiographic complete response (rCR) to palbociclib plus fulvestrant, followed by letrozole after fulvestrant injection intolerance. The patient exhibited near-complete regression of metastatic lesions within 18 months and maintained remission for over 6 years, far exceeding the typical median progression-free survival observed in clinical trials. The prolonged remission observed underscores the existence of biologically distinct tumor subsets with exceptional sensitivity to CDK4/6 inhibition, warranting investigation into underlying molecular mechanisms.
SN - 2234-943X
ER -