The evolution of cancer care
For more than 100 years, scientists have been searching for better ways to treat cancer. The development of radiation therapy in the early 1900s and chemotherapy in the 1940s were two milestones. But both had significant drawbacks.
Early chemotherapy drugs lacked the selective capacity to distinguish between cancer cells and normal cells, resulting in toxic and sometimes intolerable side effects for patients. Radiation therapy initially was shown to cause cancer in addition to treating it.
Both therapies have become more targeted thanks to advances in medicine, and researchers have found ways to minimize side effects. Today, radiation therapy and chemotherapy are considered the standard of care in treating cancer patients and millions of survivors have lived longer as a result.
But these therapies still have limitations. For example, two patients displaying symptoms and imaging results associated with a certain cancer might be prescribed the same chemotherapy regimen and experience drastically different outcomes. Why? Because the root cause of their disease and the treatment needed are different.
Researchers have been studying the root cause of disease since the Human Genome Project, completed a decade ago, opened up a whole new world of inquiry. After 13 years, researchers mapped the entire human genetic code. They found that every human is comprised of about 20,500 genes. Using this information, researchers have linked dozens of diseases such as Alzheimer’s disease and inherited colon cancer to specific genes.
In the case of cancer, researchers have discovered that two genes, BRCA1 and BRCA2, are associated with breast and ovarian cancers. Likewise, researchers have developed a drug specifically to treat breast cancers showing an overproduction of the protein HER2.
Those innovations, now standard, target genetic abnormalities inherited through a family line. In recent years, researchers have been looking at genetic mutations that have nothing to do with heredity. They have zeroed in on genomic abnormalities that occur within the disease itself. Genomic testing for cancer, in particular, looks at an individual patient’s tumor to match genetic abnormalities to a drug therapy.
The promise of precision cancer treatment
This new era of cancer treatment, called “precision medicine,” is leading to precision cancer treatment. Instead of treating cancer patients by their cancer type, stage and prior therapies, precision medicine digs deeper to the genetic level to find more appropriate treatment protocols. This shift in the way we view cancer — at the molecular level — has the potential to deliver significant benefits for patients.
Traditionally, cancer has been defined by where it occurs: Cancer in the breast is breast cancer, in the lung is lung cancer, etc. To treat cancer, the norm for patients is to try a few types of chemotherapy before the right combination is found. In recent years, though, researchers and physicians have found that a particular cancer in one patient doesn’t necessarily behave the same way in another patient. By looking at the genetic level, physicians may find that a drug never before considered for a particular cancer might be appropriate.
According to an article in The New York Times, research published in The New England Journal of Medicine and Nature suggests that genetic changes in breast, colon and lung cancers link them to other cancers. One type of breast cancer was associated with ovarian cancer. A common genetic change in colon cancer also was found in breast cancer.
Cancers now are being categorized by the underlying gene mutations that drive the cancer’s growth. An innovative new diagnostic tool, the genomic tumor assessment, examines a patient’s specific tumor genetically to identify the mechanism that caused the cancer.
An understanding of the genetic profile of a specific tumor, including the genetic changes that contributed to the tumor’s growth, allows for a truly personalized approach to cancer treatment. It paves the way for traditional cancer treatments such as chemotherapy to be replaced by less toxic, more precise drug therapies.
Genomic tumor assessment at CTCA
Our clinicians have been using genomic testing for several years as part of the standard care for patients with breast cancer and non-small cell lung cancer. Recent breakthroughs at research hospitals have revealed the value of a broader application of genomic tumor assessment.
Genomic testing examines a tumor on a genetic level to find the DNA alterations that are driving the growth of cancer. By identifying the mutations that occur in a cancer cell's genome, our physicians can better understand what caused the tumor and tailor treatment based on these findings.
Whether or not genomic testing is right for you is a decision you make with your medical team based on your individual situation. Because genomic testing is a rapidly developing area of medical science, there are currently only a few cancers where such testing is considered to be routine in the evaluation of possible treatment options. In general, physicians first will try other therapies that have been shown to be effective.
How Does Genomic Testing Work?
If you and your oncologist decide you are a candidate for genomic testing, the following steps are taken:
- CTCA collects a sample of your cancer tissue (if available) or a biopsy of your tumor and sends it to a respected genomic sequencing lab.
- Sophisticated laboratory methods will capture genomic information in the tumor cells. Scientists at the sequencing lab extract the DNA from your tissue or tumor sample.
- Genetic information is encoded as a sequence of nucleotides – guanine, adenine, thymine, and cytosine – which form the building blocks of DNA. Scientists at the lab then sequence the genes in your tissue or tumor sample to uncover the order of nucleotides.
- Sequencing the tumor’s genetic profile produces a large amount of data. Scientists at the lab analyze this data to identify mutations that are critical to certain functions of the tumor.
- Your oncologist will review the test results to determine if the information is helpful in the selection of a good treatment option for you.
Results from the sequencing lab typically take three weeks.
Genomic medicine can offer a more precise approach by tailoring treatment to a patient’s genetic information, specifically how the patient’s genes function normally or trigger disease. But not all gene mutations can be matched with an existing treatment. Your oncologist will discuss the test results with you and how these results may influence the management of your cancer.
Additionally, with our Patient Empowered Care® model, we are taking the results of these tests directly to our patients to help identify personalized treatment options, rather than using the data solely for research purposes or to create a database of tumor types.
Precision cancer treatment
What is precision cancer treatment?
Precision cancer treatment looks at a patient’s tumor on a genetic level to find what’s driving the cancer’s growth. By identifying DNA mutations in a cancer cell, our physicians can better understand what caused the tumor and tailor a patient’s treatment based on these findings.
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