How can knowing the mutations that cause a patient’s cancer shape treatment?

Question: How can knowing the mutations that cause a patient's cancer shape treatment?
- Keywords:
  mutation
Asked by TT on 21 Jun 2023.
- Zahra Rattray answered on 21 Jun 2023:
  
  This is a great question. Some mutations are very well known in causing different cancers and driving their aggressiveness. For example the genes BRCA 1 and BRCA 2 are really famous for breast and female-related cancers. If we know beforehand what mutations someone carries, we can save on time treating them with a chemotherapy that the tumour would not respond to. Also, we could protect the patient from the side effects of the treatment by not treating them on unnecessary medication, and give them the best chances of surviving their cancer by treating it sooner rather than later with effective treatment. A lot of scientists across the world are studying many different gene mutations and how they go on to cause cancer or resistance to chemotherapy.
- Jean Ling Tan answered on 22 Jun 2023:
  
  Knowing a patient’s mutation status allows clinicians to decide whether they can benefit from certain treatments. For example in lung cancer, if you have a mutation in the EGFR gene you can take EGFR inhibitors. In the context of ovarian cancer which I study, if a patient has a BRCA mutation or a mutation in genes related to a type of DNA repair called homologous recombination, they can have a type of drug called a PARP inhibitor!

Question: How can knowing the mutations that cause a patient's cancer shape treatment?