Breast cancer is a form of cancer most common in women, but can also affect men, were cells in the breast tissue become mutated and multiply. This most commonly occurs in cells around the milk ducts and glands. In the first stages there are usually no symptoms but, as cancer develops the size or shape may change and a lump could form. Some forms of this cancer are seen as hereditary due to mutated genes being passed on from the parents being linked to a risk of this type of cancer (1). But the risk can also increase due to diet, alcohol intake and age (2).
Breast Cancer can be hereditary
Breast cancer is the most common type of malignant tumour in women across the world. Around 5%-10% of these case is due to mutations in autosomal dominant genes (these are genes that are unrelated to sex chromosomes and so can be passed from either parent, only one parent is needed to pass on the mutated gene for the child to be affected.) BRCA1 and BRCA2 genes have links to cancer, as well as TP53 which results in triple negative breast cancer, which is more aggressive and challenging to treat. There is also a higher chance of it to recur or spread causing more complication in other organs. These genes have a high rate of expression but most breast cancer cases are related to a gene of low expression such as CHEK2, CDH1, NBS1, RAD50, BRIP1 and PALB2 as these are often mutated in a gene pool, therefore, causing a greater effect on the population as a whole even though there is a lower risk to an individual (3). A mutation is a change in DNA bases, three of these bases code for amino acids the building blocks of proteins (there are 20 types) there for a small change in bases of DNA can cause a change in amino acid sequence causing a protein to be ineffective. If these proteins are involved in cell proliferation control, then uncontrollable mitosis can occur.
There have also been studies that show lifestyle factors have an effect on hereditary breast cancer including BMI and alcohol intake. These studies are mainly done in western countries, so studies were needed in eastern countries to compare populations as, annually the incidence rate of breast cancer in Eastern Asia is 25.3/100,000, which is lower than that in Western Europe 89.9/100,000 and North America 76.7/100,000. This could be due to different gene pools, lifestyle or diet. One explanation they decided to investigate was the high soy diet in eastern culture compared to other countries, as studies had been done showing that increased soy intake lowers risk of breast cancer. But studies had not yet investigated the risk when comparing hereditary breast cancer of the BRCA gene to non-carrier of this gene with the same lifestyle in eastern countries. From the study, they found many comparisons in lifestyle between carries and non-carriers that are affected (4). They also saw that in non-carriers, a higher meat consummation still caused an increased risk of breast cancer, than non-meat eaters that were not the carrier of the BRCA gene. In carriers the same positive correlation between meat-eating and breast cancer was shown.
CAN ALL CANCER CELLS FORM A TUMOUR?
A study was also done where breast cancer cells were grown in immunocompromised mice, as the immune system can recognise cancer cells as abnormal and attack, preventing further growth in some cases. This study found that few cancer cells were able to form a new tumour. These cells can be identified by surface markers, then those identifiers were isolated. There were as little 100 cells that made these markers, but there are thousands of cells with other markers. As we find these markers we can more clearly understand the pathways that regulate growth and survival of these tumour cells and find treatments to stop them (5).
Treatments for Breast cancer on the NHS
There are many treatments for breast cancer depending on the type of cancer, the NHS website shows 2. Firstly there is breast-conserving surgery where only the tumour is removed or a mastectomy where the whole breast is removed this is common when cancer covers or has spread throughout the breast. After surgery some patients, with certain types of cancers, may be treated with radiotherapy this is used to kill the remaining cancer cells this usually starts a month after recovery. It can also be used after chemotherapy which is an anticancer mediation that can be used before or after surgery when the tumour is too large. This treatment is less invasive (given through a drip and sometimes oral medication is also given) meaning patients could feel more comfortable and not have to stay at a hospital. Though it also has an effect on healthy cells causing hair loss, vomiting, tiredness and loss of appetite. But on stage 2 breast cancer when cancer has spread to other parts of the body chemotherapy cannot cure cancer but may shrink it and help the symptoms of it (2).
Charities like breast cancer now fund research projects to help in the diagnoses and treatment of breast cancer such as research into antibody therapy and biomarker discovery. The aim of this group is to find a new treatment for a certain type of breast cancer called triple negative breast cancer. Which at this point has no effective treatment and the ability to identify why this type of cancer is so aggressive compared to other types. The treatment they are investigating uses antibody’s which are a type of protein used in immune response, to target specific markers on triple negative breast cancer. (6) AstraZeneca a UK based biopharmaceutical company is also doing research into Immuno-Oncology and cancer cells as the immune system finds foreign cells and destroys them. Cells that become cancerous are able to bypass this mechanism. Immunotherapy strengthens the immune system to allow recognition of these cancer cells by ‘targeted inhibition of immune checkpoints, and through the scientifically driven combination of multiple immune system-stimulating agents, including chemotherapies, small molecules, and other immunotherapies.’ (7) This research needs lab technicians and researchers to allow the procedures to be done and gain results. They may also need a nurse to administer the drug to a patient and doctors to test the effectiveness. As well as the testing of drugs then needs to be done in countries for safety approval.
There is also genetic clinics that looking to family history, work out a risk of cancer and do genetic testing. Firstly, you would meet a counsellor who can offer a genetic test if there is a strong family history. This means if a gene is found that is a risk, lifestyle choices can be taken or in some cases, medication can be prescribed (8). As well as patients being tested more regularly for cancer or from a younger age, as when caught earlier cancer has a lower mortality rate. This may require different diagnostic test and tools which need qualified people to operate. These genetic tests are done using a sample of blood, hair or skin these may need a nurse to be obtained. These are then sent to a laboratory where technicians and geneticist are needed to test the samples and give a diagnosis of risk. By look for specific changes in DNA, chromosomes and proteins, this procedure changes depending on the disorder or disease that is being looked for as it would not be effective to test for everything. This is also done for newborn babies and tests for carriers of genetic disease. (9). Labs such as Ambry Genetics, Color Genomics, GeneDX and Myriad genetics do these genetic test for breast cancer and other cancers. (10)
Novartis is now investigating artificial intelligence (AI) with start-up PathAl into the diagnostics of cancer to increase the accuracy and decrease the time. As pathologists currently diagnose from slides with thousands of cells which and are inaccurate 3-9% of the time. This requires pathologists to show the artificial intelligence samples with and without cancer cells so it can recognise patterns. As well as software developers and engineers to develop artificial intelligence so it works effectively. Data analysis must be used to see how accurate the AI is at recognising cancerous and non-cancerous sample and assess if it can be used in diagnostics. As well as nurses and medical practitioners to get cell samples (11).
- Genetics Reference 2019, Breast cancer, Genetics Home Reference, Available at: https://ghr.nlm.nih.gov/condition/breast-cancer [Accessed: 6 March 2019]
- NHS (2016) Breast cancer in women, Available at: https://www.nhs.uk/conditions/breast-cancer/ (Accessed: 6 March 2019)
- Sheikh A1, Hussain SA, Ghori Q, Naeem N, Fazil A, Giri S, Sathian B, Mainali P, Al Tamimi DM (2015) ‘The spectrum of genetic mutations in breast cancer’, Asian Pacific journal of cancer prevention, 16(6):2177-85. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25824734 (Accessed: 6 March 2019).
- Ko, KP. Kim, SW. Ma, SH. Park, B. Ahn, Y. Lee, JW. Lee, MH. Kang, E. Kim, LS. Jung, Y. Cho, YU. Lee, B. Lin, B. Lin, JH. Park, SK. (2013) ‘Dietary intake and breast cancer among carriers and noncarriers of BRCA mutations in the Korean Hereditary Breast Cancer Study ‘, The American Journal of Clinical Nutrition, 98(6)1493-1501 [Online]. Available at: https://academic.oup.com/ajcn/article/98/6/1493/4577354 (Accessed: 6 March 2019).
- Al-Hajj, M. Wicha, MS. Benito-Hernandez, A. Morrison, SJ. Clarke MF. (2003) ‘Prospective identification of tumorigenic breast cancer cells’, PNAS Proceedings of the National Academy of Sciences of the United States of America, 100(7)3983-3988 [Online]. Available at: https://www.pnas.org/content/100/7/3983 (Accessed: 6 March 2019).
- Breast Cancer Now(?) ‘Antibody therapy and biomarker discovery team’ [Online]. Available at: https://breastcancernow.org/breast-cancer-research/our-research-projects/antibody-therapy-and-biomarker-discovery-team (Accessed 8 March 2019)
- Astrazenica (2018)’immuno-oncology’ [Online] Available at: https://www.astrazeneca.com/our-focus-areas/oncology/immuno-oncology.html (Accessed 8 March 2019)
- Cancer Research UK (2018)’Genetic testing for cancer risk’ [Online] Available at: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/inherited-cancer-genes-and-increased-cancer-risk/genetic-testing-for-cancer-risk (Accessed 8 March 2019)
- Genetics Home Reference (2019)’How is genetic testing done?’ [Online] Available at: https://ghr.nlm.nih.gov/primer/testing/procedure (Accessed 8 March 2019)
- Facing Our Risk of Cancer Empowered (FORCE)(2018)’Genetic testing for Hereditary cancer’[Online] Available at: https://www.facingourrisk.org/understanding-brca-and-hboc/information/hereditary-cancer/genetic-testing/basics/labs-offering-genetic-testing.php (Accessed 8 March 2019)
- Elizabeth Dougherty (2018)’ Artificial intelligence decodes cancer pathology images’ [Online] Available at: https://www.novartis.com/stories/discovery/artificial-intelligence-decodes-cancer-pathology-images (Accessed 8 March 2019)