Immunohistochemistry versus PCR Technology for Molecular Subtyping of Breast Cancer: Multicentered Expereinces from Addis Ababa, Ethiopia

Dessiet Oma; Maria Teklemariam; Daniel Seifu; Zelalem Desalegn; Endale Anberbir; Tamrat Abebe; Solomon Mequannent; Solomon Tebeje; Wajana Lako Labisso

doi:10.15430/JCP.2023.28.2.64

Immunohistochemistry versus PCR Technology for Molecular Subtyping of Breast Cancer: Multicentered Expereinces from Addis Ababa, Ethiopia

J Cancer Prev. 2023 Jun 30;28(2):64-74. doi: 10.15430/JCP.2023.28.2.64.

Authors

Dessiet Oma¹, Maria Teklemariam¹, Daniel Seifu², Zelalem Desalegn³, Endale Anberbir⁴, Tamrat Abebe³, Solomon Mequannent⁵, Solomon Tebeje¹, Wajana Lako Labisso⁶

Affiliations

¹ Department of Medical Biochemistry, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
² Department of Biochemistry, University of Global Health Equity, Kigali, Rwanda.
³ Department of Microbiology, Immunology, and Parasitology, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
⁴ Department of Surgery, School of Medicine, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
⁵ Department of Pharmacology, School of Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
⁶ Department of Pathology, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia.

Abstract

The application of immunohistochemistry (IHC) for molecular characterization of breast cancer (BC) is of paramount importance; however, it is not universally standardized, subject to observer variability and quantifying is a challenge. An alternative molecular technology, such as endpoint reverse transcription (RT)-PCR gene expression analysis, may improve observer variability and diagnostic accuracy. This study was intended to compare IHC with the RT-PCR based technique and assess the potential of RT-PCR for molecular subtyping of BC. In this comparative cross-sectional study, 54 BC tissues were collected from three public hospitals in Addis Ababa and shipped to Gynaecology department at Martin-Luther University (Germany) for laboratory analysis. Only 41 samples were qualified for IHC and RT-PCR investigation of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 protein expression analysis. Kappa statistics was used to assess the concordance between the two techniques. The overall percent agreement between RT-PCR and IHC was 68.3% for ER (positive percent agreement [PPA] 71.1%; negative percent agreement [NPA] 33.3%), 39.0% for PR (PPA 14.3%; NPA 92.3%), and 82.9% for HER2 (PPA 62.5%; NPA 87.9%). Cohen's κ-values of 0.018 (< 0.20), 0.045 (< 0.200), and 0.481 (0.41-0.60) were generated for ER, PR, and HER2, respectively. Concordance for molecular subtypes was only 56.1% (23/41) and 0.20 kappa value. IHC and endpoint RT-PCR techniques have shown to be discordant for 43% samples. Molecular subtyping using endpoint RT-PCR was fairly concordant with IHC. Thus, endpoint RT-PCR may give an objective result, and can be applied for BC subtyping.

Keywords: Breast cancer; Immunohistochemistry; Molecular subtypes; Reverse transcription polymerase chain reaction.

Grants and funding

FUNDING This work was funded by Addis Ababa University and the thematic research group “To explore predisposing, genetic driving factors for aggressive nature of Ethiopian breast cancer and establish application of breast cancer data base management”. A Clinic and Polyclinic for Gynecology, Martin-Luther University, Halle Saale, Germany covered for laboratory analysis.