The human body is a universe of cells that help us perform all of life's functions. Cells form our muscles and bones. They help us turn food and oxygen into energy. They communicate and cooperate with the cells around them. But some cells are broken, forming mutations or abnormalities that cause destructive cellular behavior. When that happens, cancer may form.
"Normal cells are very much in tune with the rest of the body and where their place is. But cancer cells don’t follow these rules," says Shayma Master Kazmi, MD, RPH, Hematologist-Oncologist & Medical Oncologist at Cancer Treatment Centers of America® (CTCA) in Philadelphia.
For example, normal cells know when to stop growing; cancer cells grow out of control. Normal cells are programmed to die when they mutate; cancer cells survive even after becoming effective.
Some of these mutations become important drivers, dictating, say, where the tumor develops, how aggressively it grows, or whether it spreads. These are potential keys to unlock cancer’s mysteries: traits that, if neutralized, may stop the tumor from growing, spreading—or even surviving.
That’s the goal of precision cancer treatment: to get to the heart of how an individual cancer formed and counteract the behaviors that give it life. It’s an emerging model of care that takes a more targeted, personalized approach to treating cancer.
The most important breakthroughs have come in three areas of precision cancer treatment: advanced genomic testing, targeted therapies and immunotherapy.
Advanced genomic testing is a diagnostic tool designed to identify specific mutations in the DNA of cancer cells. Some cancers may have no known mutation, and some may have only one; others may have several—any one of which could be driving the growth of the tumor. If a mutation is recognized, it may help doctors recommend a precision cancer treatment that targets only the cells with those mutations. Advanced genomic testing, though, is not recommended for all patients. One of the precision cancer treatments that may be recommended based on the results of advanced genomic testing is targeted therapy.
Targeted therapies are drugs or other substances designed to seek out and find specific genes or proteins that may be unique to cancer cells or influence their behavior. When they've reached their target, these drugs may either kill the cell or help other treatments, such as chemotherapy, work better. Targeted therapy is an evolving science, and not all cancer types may be treated with targeted therapy drugs.
Immunotherapy is a broad category of cancer therapies that use the body’s immune system to fight cancer cells. That’s how the immune system typically works—by attacking infection and disease and protecting the body from foreign invaders. But because cancer cells are the body’s own cells, many escape its normal defenses. They avoid attack by sending deceptive signals to immune cells at certain “checkpoints,” making them appear as if they’re normal. Some immunotherapy drugs, called checkpoint inhibitors, are designed to disrupt those signals and expose cancer cells as harmful, so the immune system is more likely to attack them.
Because this is a new line of treatment, immunotherapies are only available to patients who meet certain criteria, which often include their cancer type and may include whether they have exhausted standard treatment options. But new and evolving clinical trials are teaching researchers more about immunotherapy’s potential uses.
Cancer is extraordinarily adaptable, but so are the tools being developed by the medicine and science community. New discoveries are being made all the time in an effort to outsmart the behaviors coded in cancer’s broken DNA profiles. “There’s an explosion of information about immunotherapy and the basic concept of trying to assist patients to use their own immune system to fight the cancer,” says Pamela Crilley, DO, Chair of Medical Oncology at CTCA®.