Introduction to Precision Oncology
Precision oncology is more than the latest buzzword in oncology. Precision oncology is a revolutionary class of chemotherapy medicines designed to specifically target the cancer and spare the patient.
Many normal cells of our body can duplicate themselves as necessary. Think of the red blood cells that continuously replenish themselves by making more red blood cells to replace the ones that hit the end of their lifespan or are lost through bleeding. These cells grow at a normal rate and stop when there are enough of them for normal body functioning.
Tumor cells start as normal cells but become a cancer when they duplicate themselves more than necessary. This runaway growth of cells is what produces the tumors found clinically. Within these tumor cells, the mechanism that controls cell duplication is broken.
In normal cells, the genes that cause a cell to duplicate are called proto-oncogenes. These genes are necessary to support normal bodily function by replenishing cells that are lost like the red blood cells. When these genes are mutated, the become unregulated and are then called oncogenes. These oncogenes are also called the driver mutations when they are the drivers of the runaway cell duplication.
Science has discovered many of the mutations that are responsible for causing the oncogenes to cause uncontrolled cell growth. Science then discovered medicines that selectively target these driver mutations. These medicines are therefore considered precision oncology because they selectively target the tumor cells containing the driver mutation but do not affect the normal cells that do not contain the driver mutation. This has increased the effectiveness of these precision oncology medicines and decreased the side effects. Some of these medicines are in pill form and allow the patient to take their medicines in the comfort of their home.
The most famous precision oncology medicines involve the epidermal growth factor receptor (EGFR) found in lung cancer cells. Mutations in EGFR promote uncontrolled cell duplication but can be stopped by using medicines that target the EGFR mutation. Some of these medications are called erlotinib (Tarceva), geftinib (Iressa), and afatinib (Gilotrif) and have had remarkable effects in treating patients with lung cancers with driver mutations that affect EGFR.
Chemotherapy has come a long way over the past decade with the rise of precision oncology medicines. They truly are better than “grandpa’s chemo” that used to be a race between these older chemotherapy medicines killing the cancer versus killing the patient. With these advancements in precision oncology, science is making lung cancer a disease we die with, and not from. But there is a lot of work that still needs to be done to discover all of the driver mutations and develop medicines to target each one.
This work will continue ‘Til No One Dies of Lung Cancer!
