Cancer and Precision Medicine
Imagine if all your medications and treatments were chosen just for you, to meet your needs based on information gleaned from your genetic code. Scientists want to make this a reality-and it could happen sooner than you think.
The field of precision medicine, “takes into account individual variability in genes, environment and lifestyle for each person.” The information gained from genetic tests empowers physicians to predict which treatments will be most effective for each individual patient.
There are already several companies that offer direct-to-consumer genetic testing, such as 23andMe, Color Genomics, and Counsyl. These companies test for genes that may increase the risk of certain debilitating diseases like Parkinson’s. People around the world are intrigued by the notion that they are more in control of their own health than ever before.
The area of precision medicine that is showing the most promise is that of cancer treatment. Cancer is caused when cells mutate and then divide uncontrollably. Because it is constantly mutating and building resistance to commonly used therapies, cancer is difficult to treat. In addition, treatments like chemotherapy indiscriminately affect both healthy native cells and malignant cancer cells, causing unpleasant side effects such as hair loss, fatigue and decreased immunity. Chemo saves lives, but researchers wondered if there was a way to specifically eradicate cancer cells while preserving healthy ones.
Already scientists have developed a number of drugs and therapies that have been effective in treating cancer in patients with a specific genetic mutation, protein, or other structure that has been identified through genomic testing. For example, Keytruda (pembrolizumab) is an IV immunotherapy treatment given to patients with certain types of cancer who test positive for the protein PD-L1. Keytruda may prevent this protein from attacking T-Cells, the body’s disease-fighting powerhouses. Another drug, Cyramza (ramucirumab) inhibits the protein VEGF (Vascular Endothelial Growth Factor) by attaching to one of its receptors. This may slow a tumor’s growth by obstructing blood flow.
Other types of precision cancer therapies block molecular activity, cause cancerous cells to undergo apoptosis (controlled cellular death), or instigate the immune system to destroy cancer cells. Research in this area continues, and it is likely we will see many more targeted cancer treatments in the future.
Some of the most intriguing studies in cancer research concern the CRISPR/Cas9 systems. CRISPR refers to repeated sequences of genetic code used by bacterial species to deactivate viruses. Cas9 is an enzyme that is used to snip away a DNA sequence and change or replace it. Scientists believe that with more testing, this technology has the potential to fix mutated cells and prevent or treat cancer.
While these targeted therapies are by no means a universal cure for all cancers, they can help improve the prognosis for some patients.
Sources
General Information:
https://www.cancer.net/navigating-cancer-care/cancer-basics/genetics/genetics-cancer
CRISPR:
http://www.crisprtx.com/gene-editing/crispr-cas9
CYRAMZA:
https://chemocare.com/chemotherapy/drug-info/ramucirumab.aspx
KEYTRUDA:
