Efficacy and safety of concomitant chemo-endocrine therapy in neoadjuvant treatment of hormone-positive HER2-negative breast cancer: a systemic review and meta-analysis

ABSTRACT

Background

The rate of pathological complete response (pCR) with both chemotherapy alone (CT) and endocrine therapy (ET) in the neoadjuvant (Na) treatment of hormone receptor (HR)-positive/HER2-negative breast cancer (BC) is unsatisfactory. Limited data on neoadjuvant concomitant chemotherapy and endocrine therapy (NaCET) are available.

Research design and methods

In this meta-analysis analyzed the efficacy and safety of randomized controlled trials (RCT) comparing the use of NaCET in HR-positive/HER2-negative BC. A comprehensive search was performed on PubMed, Cochrane Library and EMBASE databases, and congress paper lists for studies published/presented until 1 December 2022.

Results

Five RCTs involving a total of 630 patients were included. A pooled analysis of the five studies demonstrated that the pCR ratio was numerically higher in the NaCET arm than in the NaCT arm, but the difference was not statistically significant (6.5% vs. 3.8%; OR:1.72, 95% CI 0.82–3.62). Nonetheless, the NaCET arm exhibited a significantly higher objective response rate (ORR) (82% vs. 72.7%; OR:1.77, 95% CI 1.20–2.62). There was no difference between the arms in terms of grade 3–5 adverse events.

Conclusions

In HR-positive/HER2-negative BC, NaCET significantly increases ORR without an increase in serious adverse events. Although the pCR rate increased numerically, it was not statistically significant.

KEYWORDS:

• Breast cancer
• neoadjuvant
• concomitant
• chemotherapy
• endocrine therapy
• meta-analysis

Article highlights

• Pathological complete response (pCR) rates are low with neoadjuvant chemotherapy (NaCT) in hormone receptor (HR) positive, HER2-negative breast cancer.

• Currently, chemotherapy is generally used in this patient group if there is an indication for neoadjuvant therapy. In addition, neoadjuvant endocrine therapy (NaET) may be considered for select postmenopausal patients.

• The efficacy and safety of a combination of neoadjuvant chemotherapy and endocrine therapy (NaCET) have been investigated in some randomized trials to improve oncologic outcomes.

• This meta-analysis performed a joint analysis of randomized studies to assess the efficacy and safety of NaCET.

• The findings of this study indicate that the objective response rate with NaCET is significantly higher than NaCT. Although the pCR rates were numerically better in the NaCET group, the difference was not statistically significant.

• No significant increase in grade 3-5 adverse events was observed with the combination of NaCET.

• Based on these results, the combination of NaCET may be a preferable treatment option for patients with locally advanced HR-positive/HER2-negative breast cancer who require neoadjuvant therapy.

Author contribution

Y Ergun contributed to: study design, screening, data extraction, quality assessment, data synthesis, writing original draft, writing (review and editing). G Ucar contributed to: data collection, verifying data extraction and quality assessment results, writing original draft, writing (review and editing). B Akagunduz contributed to: data collection, verifying data extraction and quality assessment results, writing original draft, writing (review and editing).

Declaration of interests

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.