Doctors have known for decades that two patients with the same kind of cancer can respond very differently to the same therapy. One patient’s tumor might respond as hoped, while another’s responds little or not at all. One patient might show no sign of cancer’s return years after treatment, while another experiences a relatively quick return.
The uncertainty after prescribing treatment often leaves doctor and patient alike to wait and to wonder, “Will it work?”
Genomics and genomics-based medicine is reducing that uncertainty.
Cancer is caused by changes in genes that gradually transform a healthy cell in the body into a cell that grows out of control and forms a tumor. Thanks to advances in technology, doctors have learned a lot about the gene changes that cause cancer and that there is no routine cancer. Genomics and genomics-based medicine are among the most powerful of those advances.
- “Genomics” is the study of all of the genes in humans or other organisms.
- “Cancer genomics” is the study of the genes that are altered in cancer cells.
- “Genomic technology” refers mainly to the equipment developed for gene and genome sequencing (identifying the exact order of chemical bases in genes).
- “Whole exome sequencing” involves sequencing all 20,000 known genes in the human genome; “cancer genomics” can involve sequencing a handful of key genes for cancer diagnosis or thousands of genes for a research study.
In the 1990s and early 2000s, researchers could study one or a few genes at a time for changes that might contribute to cancer. Today, novel genomic technologies permit the study of hundreds or thousands of genes at a time.
“Genome sequencing technologies allow us to rapidly and cost-effectively characterize cancer-related genes in ways that weren’t possible 10 years ago,” says Dr. Sameek Roychowdhury, MD, PhD, a medical oncologist and specialist in cancer genomic medicine at the OSUCCC – James. “Genomic technology provides us with tools to better understand a patient’s cancer.”
Genomics in Cancer Research
Used in research, genome sequencing helps define the most significant changes in cancer cells. That information furthers cancer research in many ways, including:
- Identifying molecular indicators, or biomarkers, that can more precisely identify the type and subtype of cancer in a patient.
- Allowing the development of new “smart” drugs, or targeted therapies, that go after specific genetic changes in cancer cells.
- Helping scientists understand how cancers develop drug resistance and, then, how to reverse or prevent it.
Genomics in the Clinic
Genome-based medicine is gradually being used in the clinic. The sequencing of patients’ tumor cells can help doctors:
- Better diagnose a patient’s particular cancer;
- Better determine the patient’s prognosis, or the risk that the cancer will return;
- Identify the best therapy or clinical trial for a patient based on the genetic changes in his or her particular tumor.
“New lung-cancer patients at the OSUCCC – James are currently tested for mutations in 12 genes to help guide their therapy,” says lung-cancer specialist Gregory Otterson, MD. “Genomics in cancer care helps us identify the right treatment for the right patient.”
That, in turn, can help ease the anxiety behind the question, “Will it work?”
Visit cancer.osu.edu for more information on how genomics is helping create a cancer-free world.
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Category: Research and Education