Precision medicine helps determine the right treatment for the right person at the right time based on their individual differences in genes, environment, and lifestyle. This relatively new approach to predicting the potentially most-effective treatments for people with cancer depending on their cancer has radically changed the field of oncology over the last five to 10 years. Major advances in precision medicine are already changing lives today, and we plan on seeing significant progress that will impact more lives in the years ahead.
The underpinnings of cancer are genetic in nature
Our DNA contains more than 3 billion base pairs, which are organized into approximately 30,000 genes. This structure is akin to the binary code that forms the basis for the enormous informational capacity of supercomputers—but DNA is comparable to 3.3 billion lines of (complex human) code, while Windows 10’s lines of code total 50 million.
Genes are responsible for the structures, proteins, and activities of every cell in our body, telling our cells how to grow, differ, live, thrive, and even die. Cancer cells are abnormal cells that don’t grow, mature, develop, or die normally—dividing without control and invading nearby and distant tissues.
Genetics helps us find the cellular changes that can lead to bizarre, dangerous, and potentially lethal abilities. If we know the changes, precision medicine enables us to see a path to overcoming the cancer by targeting therapies to those abnormalities.
Many cancers are associated with nonrandom chromosomal changes
Patients can acquire gene mutations that lead to cancer through:
- Inherited gene mutations – 5 to 10% of cancers arise from familial inheritance of mutated genes
- Environmental exposures
- Tissue inflammation
Very few cancers are triggered by a single mutation. A person most likely develops cancer from multiple triggering events that happen in a certain order. In genetics, we realized early on that cancer cells are full of abnormalities, but many are nonrandom from the production of new genes or a change in how the genes are instructing the body to grow and develop. This knowledge is essential to understanding why precision medicine plays such an important role in the evolution of cancer care.
The role of DNA and proteins in cancer
DNA alone doesn’t lead to the development of cancer. Genes encode proteins, and proteins dictate cell function. For our bodies to move, develop, grow, and function, genes need to express information through proteins, which form the building blocks and machinery of our cells.
Proteins are diversely responsible for:
- Structural components of cells
- Cell-to-cell signaling
- Gene regulation or cell growth, development, differentiation, maturation, and programed cell death (apoptosis)
- Cellular transport
- Intracellular storage
Proteins contribute to the development, growth, metastasis, and therapeutic resistance of cancer cells. By using the new and emerging anticancer drugs developed to target the proteins found uniquely in cancer cells, physicians are helping more people win in the fight against cancer every day.
Interested in learning more about precision medicine? Read our Genetics to genomics: a testing revolution blog post.
Last updated Aug 2, 2021
This post was medically reviewed by Dr. Howard ‘Jack’ West.