Dr. Meenu Walia, is the first DNB medical oncologist of India who has been the principle investigator of several Multi-Centric International Clinical Research trials where newer options for Cancer treatment are evaluated.
A detailed Q & A on it:
What is Precision Medicine?
There have been significant advancements in technology and availability of genomics testing, which has led to a new innovative approach to medicine, called “Precision Medicine”. It takes into account the individual differences in people’s genes, environments, and lifestyles. This allows doctor to understand the complex mechanisms underlying a patient’s health, disease, condition and to evaluate which treatments will be most effective.
Just as a person who needs a blood transfusion is not given blood from a randomly selected donor; instead, the donor’s blood type is matched to the recipient to reduce the risk of complications; Precision medicine uses genomics testing for treatment of diseases like Cancer to identify the right and better treatment for an individual patient.
What role does it have in cancer treatment?
Cancer is basically caused by mutations or changes in genes, which control the growth and death of normal cells. Mutations in these genes end up in the genome in different ways. Germline mutations are those that are hereditary, such as women born with the BRCA mutations. They have a higher risk of developing breast and ovarian cancer as adults. Acquired mutations such as the HER2-positive breast cancer are mutations that have been developed over time due to environmental and lifestyle factors.
Recently, doctors have started using these treatments based on the driver mutation, and not only on the location of the tumour. Research and Precision Medicine has now shown that it is no longer important to know from where did the disease originate, or if the tumor is in the liver or lung or in the breast—what is significant from a treatment perspective is the genetic driver of the disease.
In what way, is this new treatment different from existing cancer treatments?
Conventional medicine treatment treats cancer based on the type of disease and the damage to specific organs. In simple words, it is like a ‘blanket treatment ‘or informed guess work for most cancers. However, the new approach focuses on the defective genes, thereby driving the disease and using that information to determine which drugs or combination of drugs, will work best for a particular patient.
How is it better than existing cancer treatments?
Existing cancer surgery and treatment is a system of trial and error & hence, does not work for some patients. With this new approach, patients can be given the right treatment first, instead of common blanket treatment.
Clinical trial involving more than 13,000 patients found that those given targeted treatments, had disease stalled and tumour shrink 6 times the rates than those given the standard treatment. Tumours in patients who received targeted treatments had shrinkage rates of 30.6%, as compared to 4.9% in those people who did not receive it.
How is this treatment personalised?
Personalisation may take different forms when it comes to cancer. These include:
- Cancer testing to determine whether a particular treatment would be effective in a particular case,
- Genetic profiling of the patient to understand whether he/she can handle a particular medicine or therapy and
- Profiling the genetical composition of a person in regards to genetic mutation to determine the degree of cancer risk.
What is the current status?
Precision medicine is still in its infancy in India. However, it was opened door to a whole new world of tremendous possibilities in treatment of a deadly disease like cancer.