Genes are what makes us who we are. The DNA in our cells is the building block for all life. These genetic codes are unique to creating proteins, cells, muscle, tissues and organs as well as giving us our characteristics varying from hair colour to our height. They can also tell us extremely important information whether we may be at higher risks to specific diseases and also how our bodies will react to different courses of drug treatment. These principles are used in modern day uses of personalised medicine. Early forms of personalised medicine have already been used by incorporating a patient's lifestyle and family history to inform decisions about treatment. This helped to grasp whether the patient may be at risk to certain diseases due to family history and environmental factors. One example would be type 2 diabetes which can be caused by a person's lifestyle. However ever since the first genome was sequenced in 2000 personalised medicine has been able to develop due to advances in modern day scientific techniques and technology. Currently studies of specific patient's genomes have shown that genetics can determine personal disease susceptibility as well as reactions and effectiveness of certain drugs.
Current studies in personalised medicine are carried out in a specific way. Firstly the patient's family history is assessed. Then their genome is sequenced and analysis is performed focussing on particular genes. Next risk predictions may be worked out for particular disease that the scientists are focussing on and screening for individual disease may also be implemented. (Ashley, E.A., et al. 2010).The patient would then undergo genetic counselling that assesses the risk, treatments and the mitigation of specified genetically inherited disorders. (Ashley, E.A., et al. 2010).This method shows the use of personalised medicine and how it leads to discovery of genetic variants which represent specialised disease risk as well as recognising the patient's individual drug Reponses and how successful treatment methods would be.
There are many ethical issues involved with sequencing a patient's genome and looking at their disease susceptibility and specific drug effectiveness. When the study is completed there are worries about who should have access to the genetic information. This is because it could be perceived as invading privacy if you do not have the patient's permission to use their personal information. There may also be implications to person's health and welfare due to information that they find out from the study. (Ashley, E.A., et al. 2010). The other issue is fact of counselling that it should be given before and after. (Ashley, E.A., et al. 2010). Finally there must be legislation put in place to prevent the misuse of the information obtained from the personalised medicine examination. (Ashley, E.A., et al. 2010).
Some advantages of personalised medicine are that scientists are able to build up a catalogue of genetic variants that increase risk of particular common diseases. The other benefit is due to the technological progress of genome sequencing. The advancement has meant that the cost sequence a genome has decreased significantly from £2.7 billion to £10,000 which is a fraction of the price. Predictions for future genome sequencing estimate it could decrease further to as little as £1000. (Ashley, E.A., et al. 2010).
The most common cancer in women in the UK is breast cancer. In cancer related deaths it is the second leading cause and has an annual incidence rate of 109.8 per 100,000 in our population. (Coleman, W. B., et al. 2009).
Breast cancer diagnosis and prevention has developed a lot through the years with improvements in screening methods and treatment that have led to a decline in breast cancer related deaths. At a molecular level the disease is heterogeneous. This characteristic lead to the discovery of biomarkers. Current research is exploring biomarkers and how they can be used for improved prediction of the disease course and outcome including specific response to treatments. (Coleman, W. B., et al. 2009).These biomarkers can help lead towards specified treatments that can be tailored individually for a breast cancer patient's needs. (Coleman, W. B., et al. 2009).
Many clinical studies have focussed on looking at how breast cancer risk may be increased by the presence of specific alleles in a person's genome. One example of how personalised medicine is at the forefront of research is research into single nucleotide polymorphisms (SNPs) and how they can change risk of contralateral breast cancer (CBC). One of the most common second primary cancers seen in patients is CBC. (Swain, S.M., & Wedam, S.B., 2005). The risk of getting CBC is increased if the patient already had a history of breast cancer. (Swain, S.M., & Wedam, S.B., 2005). Patients with cancer are two to five times as likely to progress to CBC as women are to obtain breast cancer originally. (Taraoka, S.N., et al. 2011).
The recent study of single nucleotide polymorphisms associated with risk for contralateral breast cancer in the Women's Environment, Cancer, and Radiation Epidemiology is a study that uses personalized medicine techniques to examine how genes can be associated with an increased risk of CBC. The investigation was carried out after the previous WECARE study to build on results and draw further conclusions about the study. The WECARE study was a study of 708 women with asynchronous bilateral breast cancer and the control of 1,394 women with unilateral breast cancer. (Taraoka, S.N., et al. 2011). The investigation focussed on how radiation treatment could have acted as a carcinogen. It looks at the presence of the ataxia telangiectasia mutated gene (ATM gene) and whether when treated with radiation it can cause the patient to have a higher risk of developing second primary CBC. (Taraoka, S.N., et al. 2011). The cases were individually matched into case-control triplets using age, time of diagnosis, race and registry region. (Taraoka, S.N., et al. 2011).Each triplet consisted of two women which received radiation treatment and the other which did not receive radiation treatment. (Taraoka, S.N., et al. 2011). They built up medical records for all the women in the investigation for example records of estrogen receptor status (ER) and type of first cancer treatment were added to the records.
The research of Single nucleotide polymorphisms associated with risk for contralateral breast cancer in the Women's Environment, Cancer, and Radiation Epidemiology (WECARE) Study was carried out after the previous investigation. They took the same number of patients as studied before and used the extensive amounts of records on each patient to further develop the research. The study goes into depth looking at women with CBC and how co factors such as radiotherapy, chemotherapy, ER status of the first tumor and hormonal exposures can affect the risk of developing CBC after primary breast cancer. (Taraoka, S.N., et al. 2011). The results gained from the investigation have discovered specific SNPs that are associated with an increased risk to CBC and some show relationship between increased risk and the ER status of the first tumour. Substantial relationships with CBC were identified at a number of places for example at rs7313833, near the PTHLH gene. (Taraoka, S.N., et al. 2011). Secondly two separate alleles were identified to be significant to ER positive and ER negative first tumours.
In conclusion of the study it was found that risk of CBC was increased by the most common risk variants for primary breast cancer. (Taraoka, S.N., et al. 2011). From previous genome wide associations studies of unilateral breast cancer six out of the twenty one SNPs had important associations to CBC. (Taraoka, S.N., et al. 2011). Two of the six associated were also related to the ER status of the first tumour. (Taraoka, S.N., et al. 2011). Finally a relationship was seen between radiation dose from previous treatment and the increased risk of CBC. I used this journal to look at an example of how personalised medicine is used to day at the forefront of research. Breast cancer is one of the main diseases that is at the forefront of personalised medicine as every sufferer is unique and will develop different types and have various reactions to specific drugs. Breast cancer is the second leading cause of cancer related deaths so modern day techniques must keep evolving to further advance personalised medicine to a future where we can successfully treat it. In 5-10 years' time to constant building on previous research may lead to better treatment of breast cancer however I believe it will take longer to completely cure the disease but developments may lead to the decrease the incidence rate of breast cancer and maybe increase the success rate of treatment through the medical treatment being customised for the specific patients genes.
We are only at the tip of the iceberg of personalised medicine. This type of medical care is still very young and has far to progress into the leading form of medicinal care for future generations. Today it may be just starting to look into more depth at cancer especially breast cancer and how the disease works and the effective unique treatments for an individual. In the future development of genome sequencing to reduce cost could lead to health care storage and analysis of patient's genomes. In years to come patients could get there personal genome analysed to see specific disease risk, drug effectiveness and also may alter their lifestyles for the better. For example if someone had an increased risk of developing type 2 diabetes they may be advised to have a more healthy lifestyle to reduce risk. We may be far off whole populations getting their genomes sequenced however research and development of technology will lead to more diseases early diagnosis, more effective drug treatment and personal courses for an individual. Leading to greater effectiveness of healthcare and the future in which cancer can be treated successfully.
