While the old adage, ‘one size does not fit all’ can be true in all walks of life, perhaps it is most relevant today in medical domain. Related to this wisdom is a concept called ‘Personalised Medicine’ or ‘Precision Medicine’ that is currently gaining momentum particularly in oncology.

What is personalised medicine?

Personalised medicine is nothing new. A simple example of this is seen in process of blood transfusion. The donor blood sample is tested for compatibility and transfused only if there is a match with the recipient. A logical extension of this concept was to explore the possibility of variable therapy in cancer depending on the genetic patterns/mutations. With the Human Genome Project (HGP) completion in 2003, scientists have successfully identified and mapped most of the human genetic information and hence the concept of personalised medicine is now a reality.

Application of personalized medicine in oncology1, 2

Use of personalized medicine, also known as precision medicine in cancer, comes from studies of human genes in healthy individuals and in different cancers. These studies have helped scientists develop specific genetic tests for different cancers and tailor appropriate therapy based on the available genetic information.

Personalised cancer treatment has many benefits. Some of them are:

a) Improved ability to predict which treatment will work best for specific patients: All patients with breast cancers may not respond to the same therapy. For example, breast cancer patients testing positive for HER 2 will respond to a different drug as compared to a patient testing positive for BRCA1/BRCA2 test. While the former is identified with a test known as ImmunoHistoChemistry (IHC), the latter is tested with hereditary genetic tests such as one performed by Myriad or COLOR genomics or from other laboratories in India and abroad.

b) As the therapy is more specific, treatment outcome is predictable, and patients respond better to the therapy: This is made possible by the genetic tests that suggest appropriate treatment based on the specific genetic abnormality pattern detected in the patient. Good examples of such test are: Foundationone CDX by Foundation Medicine and BGI SENTIS Cancer + Discovery panel by BGI. These tests can identify the most appropriate therapy after analysing 315 (Foundationone CDX) or 688 (BGI SENTIS Cancer + Discovery) genes.

c) Patients experience fewer side effects: Based on the concept of pharmacogenomics, it is now possible to predict how drugs interact with the enzymes inside the bodies and get metabolised. Depending on the speed of processing, it is possible to infer whether the drug will be effective or toxic. Again, Foundationone CDX by Foundation Medicine and BGI SENTIS Cancer + Discovery panel by BGI, are good examples of these tests.

In the days to come personalised medicine will help larger patient population to receive specific treatment with fewer side effects and predictable positive outcome.

References:

  1. What Is Personalized Cancer Medicine? Cancer.net. Accessed on 18th May 2020 at URL:
    https://www.cancer.net/navigating-cancer-care/how-cancer-treated/personalized-and-targeted-therapies/what-personalized-cancer-medicine
  2. Precision Medicine. Accessed on 18thMay 2020 at URL:
    https://ghr.nlm.nih.gov/primer/precisionmedicine/potentialbenefits