By Janse Mahan and Marvely Molina

Marvely and I enjoyed working on this project. The whole process was very interesting although challenging because of our conflicting schedules. At first we didn’t really understand the assignment so we scheduled a meeting with Hermioni and Dr. Woodham who guided us through the steps to follow for a successful completion of the project. From there everything went smoothly. We picked a gene of interest which we believe plays a very important role in breast cancer. After gathering the information, we wrote this paper and made an infographic that we are excited to share with you.   

Introduction: 

According to WHO, 1 out of 8 people will develop breast cancer in their lifetime. Severity and prognosis differ for each breast cancer variant and so treatment and discovery of each subtype can be different, but the use of biomarkers is helpful. 

Biomarkers1 are markers used to measure and evaluate responses to a therapy. They are helpful to diagnose the disease, track its progression as well as determining the outcome of the therapy (NIH, n.d.). For cancer treatment, biomarker testing is commonly used. It is a technique which consists of finding the appropriate gene, protein or any marker that can help define the characteristics of the cancer (NIH, n.d.). There are several types of biomarkers that are classified according to their different functions (shown in figure1) : risk assessment, detection, diagnosis, prognosis, prediction, monitoring. 

Figure 1. The key functions of biomarkers. (Provista Diagnostics, 2016). 

After reading the articles, we identified 21 biomarkers, but ended up narrowing down the list to 4 key biomarkers: HER22, ER, Ki67 and Cyclin D1. After further research on these four biomarkers, we came to the term known  as “established biomarkers' '. The two that were classified as established biomarkers are ER -- an acronym for Estrogen Receptor and HER2 . In the case with HER2, it is classified as having prognostic and predictive significance and is overexpressed (Weigel & Dowsett, 2010).These two genes work well to define treatment-specific prognoses and the benefit of using chemotherapy as a treatment. Both can be detected through IHC (Immunohistochemistry) assay.  HER2 is also measured through fluorescence in situ3 (in place)  hybridization (FISH) or chromatin in situ hybridization (CISH) techniques (Wolff et al., 2007).  

We decided to focus on HER2. According to the American Society of Clinical Oncology's Tumor Marker Utility Grading System (SCOTMUGS), it is one of the most commonly used biomarkers in breast cancer development and treatment. Additionally, it acts as a predictive and prognostic biomarker. It is targeted by the monoclonal antibody trastuzumab4, and its amplification benefits from adjuvant doxorubicin-based chemotherapy (type of treatment)(Muss et al 1994, Dressler et al. 2005). The normal function of the HER2 gene is to make HER2 proteins which function as receptors on breast cells and it dominates the control of healthy cell growth, repair and division. 

Conclusion: 

Breast Cancer is a diverse disease so when HER2 is overexpressed it can identify various treatment opportunities. 

Glossary 

Biomarker: A measurable technique and substance in an organization that helps indicate a disease, infection etc. 

Monoclonal antibody trastuzumab: a highly purified recombinant DNA-derived antibody that binds with high affinity and specificity to the extracellular domain of the HER2 receptor. 

HER2: Human Epidermal Growth Factor Receptor 2 

ER: Estrogen receptor 

IHC: Immunohistochemistry 

Established biomarkers: Biomarkers used for optimized clinical decision making by providing prognostic information and predicting response to specific therapies. 

CISH: Chromatin in situ hybridization 

FISH: Fluorescence in situ 

In situ: “lobule” in place or a small lobe 

Work Cited  

NIH. (n.d.). Biomarker Testing for Cancer Treatment. Retrieved from: https://www.  

cancer.gov/about-cancer/treatment/types/biomarker-testing-cancer-treatment 

Provista Diagnostics. (2016). 6 Types of Biomarkers in Cancer Detection. Retrieved  

from: https://www.provistadx.com/blog/6-types-of-biomarkers- in-cancer  

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