Distribution of the Homologous Recombination-related (HRR) Genesmutationsand HRD in Breast Cancer

Recruiting

• Conditions: Breast Cancer; HER2-low Breast Cancer

• Registration Number: NCT05466786
• Lead Sponsor: Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University

Brief Summary

This is a cross-sectional and an observational study, investigator-initiated study in HER2-low breast cancer patients. Approximately 255 subjects with HRD (homologous recombination deficiency) assessment will be enrolled in this study to examine the distribution and features of HRD/HRR (homologous recombination repair).

In this study, investigators plan to clarify the frequency of HRR/HRD in Chinese patients with HER2-low breast cancer.

In addition, it is planned to investigate any association between invasive disease-free survival (iDFS)/overall survival (OS) and HRD/HRR in HER2-low breast cancer patients.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-07-10
• Study First Submitted QC: 2022-07-18
• Study First Posted: 2022-07-20
• Study Start: 2022-08-07
• Status Verified: 2025-09
• Last Update Submitted: 2025-09-29
• Last Update Posted: 2025-10-03
• Primary Completion: 2027-05-31
• Study Completion: 2027-05-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 255

Inclusion Criteria

1. Female patients aged 18-70 years with pathologically confirmed HER2-low breast cancer (defined as IHC 2+/ISH- or IHC 1+ per ASCO/CAP guidelines);
2. ECOG performance status of 0 or 1;
3. Treatment-naïve operable primary breast cancer with completed homologous recombination deficiency (HRD) assessment;

5）Absence of distant metastasis; 6）Availability of adequate tumor tissue and blood samples for biomarker analysis.

Exclusion Criteria

1. Recurrent or inoperable locally advanced breast cancer;
2. Bilateral breast cancer;
3. History of other malignant tumors within the past 5 years;
4. Incomplete clinical or pathological data.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
1.To assess the distribution characteristics of mHRR/HRD in breast cancer with low HRE2 expression in Chinese population	At the time of 4 weeks after surgery	the distribution and features of HRD /HRR is evaluated.

Secondary Outcome Measures

Name	Time	Method
To assess the clinical characteristics between patients with mutations and non-mutation	At the time of 4 weeks after surgery	Association between mutations and non-mutations group in HRD/HRR is assessed.
To compare the correlation between iDFS/OS and different adjuvant treatment regimens for breast cancer with low HER2 expression	At the time of 36 months after surgery	IDFS, was a composite endpoint defined as the time from enrollment until the date of the first occurrence of one of the following events: Ipsilateral invasive breast cancer recurrence (same breast); Ipsilateral (same side of body) local regional invasive breast cancer recurrence (axilla, regional lymph nodes, chest wall, and/or skin); Distant recurrence (evidence of breast cancer in any anatomic site); Death attributable to any cause; Contralateral (opposite side of the body) invasive breast cancer.; 3-year Overall survival (OS) was defined as time from date of randomization to death from any cause, otherwise cases were censored at date last known to be alive.; Association between IDFS/OS and HRD/HRR information is evaluated.
To investigate the HRR/HRD characteristics and clinical characteristics (family history, age pathological feature es, etc.) of breast cancer patients with low HER2 expression	At the time of 4 weeks after surgery	Association between multivariate prognostic factors and survival is evaluated.

Trial Locations

Locations (1)

Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University; 🇨🇳 Guangzhou, Guangdong, China