Academic Review 2024

45 ACADEMIC REVIEW 2024

How can personalised medicine be used to improve cancer treatments? According to Cancer Research UK, there were over 166,000 deaths a year caused by cancer between 2016 and 2018 in the UK. Despite many new and improved methods of cancer treatments being constantly under development, cancer remains the second leading cause of death globally. A trend backed up by a large body of evidence is that cancer treatments become less effective the later the cancer is diagnosed; research in the British Medical Journal indicated that even a one-month delay in cancer treatment can lead to a 6% to 13% higher risk of dying (Hanna, King, & al, 2020). Researchers from the London School of Hygiene and Tropical medicine, King’s College London and Queen’s University conducted an analysis of 34 studies into cancer treatment delays and mortality risks between January 2000 and April 2020 and found that ‘of the 1.2 million patients studied, the association between delay of treatment and increased mortality was significant’ (Hanna, King, & al, 2020). This is because as the time before diagnosis increases, traditional treatments for cancer such as, chemotherapy, surgical removal of the tumour, and radiotherapy become less effective. However, personalised medicine has the potential to offer a solution to tackle this devastating worldwide issue. Through the application of genomic analysis, mutations which increase the susceptibility to cancer in individuals can be identified. This allows patients who are at elevated risk of cancer to be screened regularly for early diagnosis or to implement preventative measures to reduce the risk of cancer development; the course of action typically depends on the risk of developing cancer as a result of the mutation. This demonstrates that personalised medicine can reduce the risk of cancer mortality by increasing the success rates of cancer treatment through early diagnosis. This has significant implications for developments of cancer treatments in the future, and how we can perhaps overcome cancer by extending the employment of personalised medicine in healthcare. An example of this is scanning for mutations in the BRCA1 gene. A functional BRCA1 gene produces a tumour suppressor protein that repairs double strand breaks in DNA. This is proven by the fact that, ‘Research over the last two decades has described the role of the ubiquitously expressed

BRCA1 in maintaining genomic stability through its function in DNA repair and cell cycle checkpoint control’ (Lee & Abbondante, 2014). These double strand breakages occur due to certain factors such as overexposure to ultraviolet radiation. Ultraviolet radiation causes adjacent thymine bases in DNA to dimerise (bond together) which induces a kink to the DNA strand, causing it to break. When this happens, the BRCA1 gene produces a tumour suppressor protein which prevents the patient from developing cancer. However, in some individuals, the BRCA1 gene becomes mutated, which leads to a dysfunctional tumour suppressor protein. This increases the risk of a mutation in DNA and therefore raises the probability of cells turning cancerous. Subsequent studies indicate that, ‘Germ-line mutations in the tumor suppressor gene BRCA1 increase the lifetime risk for breast cancer and ovarian cancer by up to ~80% and ~50%, respectively’ (Lee & Abbondante, 2014). This is a significant value and therefore it is critical to screen for mutations in the BRCA1 gene to identify individuals who are at an elevated risk of developing breast cancer, and swiftly provide preventative measures. However, it can be argued that screening for a mutation in the BRCA1 gene raises concerns over patient confidentially because, as a mutation in the BRCA 1 gene follows autosomal dominant inheritance, the presence of the mutation in an individual suggests that a parent must also carry this mutation. Personalised medicine can also be used to aid the treatment of chronic myeloid leukaemia. ‘Chronic myeloid leukemia is caused by a somatic mutation that results in formation of the Philadelphia chromosome, which in turn generates a mutant gene called BCR-ABL’ (Butts, Kamel-Reid, & al, 2013). Therefore, through genomic analysis, clinicians can identify the Philadelphia chromosomes or the mutated BCR-ABL gene, and therefore appropriate treatment can be given, and the efficacy can be monitored. This is a representation of the benefits personalised medicine can provide, especially in tackling a complex disease such as cancer that scientists have been working on relentlessly for decades; £388 million was spent in the year 2020/2021 in the UK alone (Cancer Research UK, n.d.).