PMID- 35355705
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20230202
IS  - 1661-3791 (Print)
IS  - 1661-3805 (Electronic)
IS  - 1661-3791 (Linking)
VI  - 17
IP  - 1
DP  - 2022 Feb
TI  - Treatment Strategy for Patients with HR-Positive HER2-Negative Metastatic Breast 
      Cancer That Progressed on CDK4/6 Inhibitors.
PG  - 16-23
LID - 10.1159/000515729 [doi]
AB  - BACKGROUND/AIMS: The study aim was to evaluate if mTOR inhibitors can be 
      considered as a treatment option for HR+ HER2- metastatic breast cancer (MBC) 
      after progression on CDK4/6 inhibitors in clinical practice. METHODS: We 
      retrospectively collected the clinicopathological data of patients with HR+ HER2- 
      MBC treated with CDK4/6 inhibitors and subsequent therapies at our institution 
      between 2014 and 2020. The patients were divided into 3 groups according to the 
      type of subsequent treatment: (A) exemestane plus everolimus, (B) endocrine 
      monotherapy, and (C) chemotherapy. Overall survival (OS) was estimated by using 
      the Kaplan-Meier method and compared by using the log-rank test. The efficacy and 
      adverse events (AEs) of each subsequent treatment were assessed by using Fisher's 
      exact tests. RESULTS: Eighty-six patients (34 in group A, 20 in group B, 32 in 
      group C) were included. The most common endocrine therapy in group B was 
      fulvestrant (40%). The major chemotherapy regimen in group C was eribulin (25%). 
      The median OS times after stopping CDK4/6 inhibitors were 34.5 months (95% 
      confidence interval, 17.2 to NA), 13.6 months (3.9 to NA), and 19.5 months (18.8 
      to NA) in group A, group B, and group C, respectively. The only significant 
      difference in OS was observed between group A and group B (20.9 months; p = 
      0.003). There was no difference in the incidence of grade 3 AEs between groups A 
      and C or in the frequency of treatment discontinuation because of AEs among the 3 
      groups. CONCLUSION: Our study shows that mTOR inhibitors might be an effective 
      treatment option for patients with HR+ HER2- MBC previously treated with CDK4/6 
      inhibitors.
CI  - Copyright (c) 2021 by S. Karger AG, Basel.
FAU - Hayama, Shouko
AU  - Hayama S
AD  - Department of Breast Surgery, Chiba Cancer Center, Chiba, Japan.
FAU - Nakamura, Rikiya
AU  - Nakamura R
AD  - Department of Breast Surgery, Chiba Cancer Center, Chiba, Japan.
FAU - Miyaki, Toshiko
AU  - Miyaki T
AD  - Department of Breast Surgery, Chiba Cancer Center, Chiba, Japan.
FAU - Itami, Makiko
AU  - Itami M
AD  - Division of Diagnostic Pathology, Chiba Cancer Center, Chiba, Japan.
FAU - Yamamoto, Naohito
AU  - Yamamoto N
AD  - Department of Breast Surgery, Chiba Cancer Center, Chiba, Japan.
LA  - eng
PT  - Journal Article
DEP - 20210521
PL  - Switzerland
TA  - Breast Care (Basel)
JT  - Breast care (Basel, Switzerland)
JID - 101254060
PMC - PMC8914266
OTO - NOTNLM
OT  - CDK4/6 inhibitors
OT  - Endocrine therapy
OT  - Metastatic breast cancer
OT  - mTOR inhibitors
COIS- The authors have no conflicts of interest to declare.
EDAT- 2022/04/01 06:00
MHDA- 2022/04/01 06:01
PMCR- 2023/02/01
CRDT- 2022/03/31 05:20
PHST- 2021/01/15 00:00 [received]
PHST- 2021/03/09 00:00 [accepted]
PHST- 2022/03/31 05:20 [entrez]
PHST- 2022/04/01 06:00 [pubmed]
PHST- 2022/04/01 06:01 [medline]
PHST- 2023/02/01 00:00 [pmc-release]
AID - brc-0017-0016 [pii]
AID - 10.1159/000515729 [doi]
PST - ppublish
SO  - Breast Care (Basel). 2022 Feb;17(1):16-23. doi: 10.1159/000515729. Epub 2021 May 
      21.