2022 IB Diploma Extended Essays

Furthermore, the analysis of sources was conducted using the acronym TOMACPRU (type,

origin, motive, audience, content, perspective, reliability, usefulness) (Don, 2016). Although

this method of source analysis is typically applied to history sources, the acronym has proved

useful in providing credible data for my research topic. As demonstrated in appendix 1.1 and

1.2, the analysis of the most used resources was conducted to ensure that the evidence

supporting my claims were justified.

Breast cancer overview

Breast cancer is a tumour formed within the breast tissue, typically within women (Cancer

Council, n.d.). This type of cancer is the most common type of cancer found in women, with

around 2.3 million women diagnosed with breast cancer by the end of 2020 worldwide

(World Health Organisation, 2021). The use of mammogram screening is currently the most

effective way for a person to be diagnosed with breast cancer. As such, the number of

mammogram screenings would directly correlate with the number of breast cancer diagnosed.

This type of cancer occurs due to the mutations which occur on the BRCA1 or the BRCA2

gene located on chromosome 17 and 13 respectively (Stanford Medicine, n.d.). Mutations

which occur in these genes are autosomal dominant, meaning they can be passed down to the

next generations (Stanford Medicine, n.d.). BRCA 1 and 2 both play a vital part in DNA

damage response (DDR) (Patrick G. Pilié, 2019). BRCA 1 functions in DNA repair and

checkpoint activation whilst BRCA 2 regulate homologous recombination (Rohini Roy,

2011).

A normal (somatic) cell goes through the processes of mitosis to create more cells and goes

through their own life cycle (Miko, 2008). However, cancer cells also undergo mitosis in a

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