“Precision Medicine” – What is It and What is all the Hype?
Precision medicine is one of the latest buzz words circulating in the field of oncology. In fact, it was the theme of the 2018 American Society of Clinical Oncology Annual Meeting. More and more, oncologists are using precision or “personalized” medicine to guide treatment recommendations. The concept is that no two patients are alike and no two cancers are alike and treatments must be individualized for each and every patient
What is Precision Medicine?
The concept of precision medicine involves examining the cancer in each individual patient and determining what is driving that tumor to grow so that it can be specifically targeted where it is vulnerable.
Where did it come from?
For decades, the treatment of cancer was based on the site of origin of the cancer – all tumors which originated in the lung were treated as lung cancer, all tumors which originated in the colon were treated as colon cancer, etc. and the treatments were the same for all patients. What oncologists and researchers have learned, however, is that not all cancers from the same organ are alike and sometimes cancers which originate from different organs can be more similar than previously thought.
The concept of precision medicine is not completely new, however. In fact, the concept has been used in the treatment of breast cancer for a long time now . Breast tumors are often treated differently depending on whether or not they express hormone receptors for estrogen and progesterone. Through recent advances in research, physicians are now able to identify similar distinguishing features for other tumor types.
How Does it Work?
There are different ways to evaluate tumors to determine the best way to treat them. Looking for certain proteins on the tumors such as PD-1 or PDL-1 or testing for microsatellite instability (MSI) in the tumor cells can often predict which tumors will respond to immunotherapy. Doctors can also test for specific genetic mutations within the tumor cells such as EGFR, ALK or ROS mutations in lung cancers and then prescribe treatments which specifically target the mutated pathways in the cancer . A more extensive anlaysis of often hundreds of genetic mutations within cancer cells can be performed with a process called next generation gene sequencing.
What are the Limitations?
Not all tumors have these distinguishing features which physicians are able to use to guide therapy. And while tests are now available to identify hundreds of different mutations in cancer cells , effective therapies for targeting these mutations has only been developed for a select few thus far. But the research is advancing at a rapid pace and researchers and pharmaceutical companies are working together to find effective targeted therapies and bring the success of precision medicine to more and more patients.
Julie Monroe, M.D. is a board certified medical oncologist who has over twenty years experience in medical practice and in conducting and overseeing clinical research. She currently maintains a private consultation practice helping those dealing with a cancer diagnosis find the best personalized treatment approach for themselves. You can reach her at www.cancerconsultingservices.com