Tumor Characteristics and Survival Rate of HER2-Low Breast Cancer Patients

Study Overview
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Brief Summary
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In this large-scale cross-sectional study, we evaluated disease-free survival (DFS), overall survival (OS), and clinicopathological characteristics of BC patients from 1991 to 2022, retrospectively. We recruited patients referred to the Cancer Research Center in Tehran, Iran, and their HER2 status, which is classified as HER2-low, HER2-positive, or HER2-negative, was obtained from prospectively maintained registries. we aimed to dive more deeply into the clinicopathological characteristics and survival features of HER2-low breast cancer patients and campared it with HER2-negative and HER2-positive groups. Question 1: Is HER2-low breast cancer (BC) a new subtype in the standard classification of BCs? Question 2: How is the DFS and OS rate of HER2-low breast cancer patients in comparison with HER2-negative and HER2-positive groups?

Official Title
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Tumor Characteristics and Survival Rate of HER2-Low Breast Cancer Patients; a Cross-Sectional Study

Conditions
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HER2 Low Breast Carcinoma

Intervention / Treatment
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* Diagnostic Test: immunohistochemistry (IHC) and in situ hybridization (ISH) Test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All breast cancer patients with human epidermal growth factor receptor 2 (HER2) status in the database of the Cancer Research Center (CRC),from April 1991 to March 2022 Exclusion Criteria: The male gender Patients with indeterminate or missing HER2 status, or patients with missing DFS and OS information
Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| HER2-low<br>patients with HER2 IHC1+ and HER2 IHC2+/ISH-negative in their pathology | Diagnostic Test: immunohistochemistry (IHC) and in situ hybridization (ISH) Test<br>* These tests are usually applied for breast cancer patients to assist the surgeon to better understand the clinicopathological characteristics and survival features of tumors<br>|
| HER2-negative<br>patients with HER2-zero in their pathology | Diagnostic Test: immunohistochemistry (IHC) and in situ hybridization (ISH) Test<br>* These tests are usually applied for breast cancer patients to assist the surgeon to better understand the clinicopathological characteristics and survival features of tumors<br>|
| HER2-positive<br>patients with HER2 IHC2+/ISH-positive and HER2 IHC 3+ in their pathology | Diagnostic Test: immunohistochemistry (IHC) and in situ hybridization (ISH) Test<br>* These tests are usually applied for breast cancer patients to assist the surgeon to better understand the clinicopathological characteristics and survival features of tumors<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| HER2-low OS | HER2-low status had the highest survival rate. | 38 months | 
| HER2-low DFS | HER2-low status had the highest DFS. | 33 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast cancer, ErbB-2, HER2-low, Disease-Free Survival, Survival Rate