How Genomic Testing Has Changed the Future of Cancer Care

The massive investment in cancer research over the past several decades has resulted in dramatic changes in how cancer is treated. One of the most important findings makes it possible to create a cancer treatment plan for some patients based on specific genetic mutations found in the cancer cells. Genomic testing, the process of identifying these mutations, is now a part of the diagnosis process for some types of cancer, with more on the horizon.

Genomic testing makes it possible to target specific mutations in the DNA to stop the cancer from continuing to grow. This would not be possible before the Human Genome Project, which mapped the entire human genome – all human genetic material.

What is genomic testing?

Genes provide the directions that cells require to make proteins. But over time, cells can mutate and begin making different proteins that cause cells to divide faster, which is how cancer tumors develop.

Genomics is the study of gene mutations (changes) in living cells. The tests are looking for specific biomarkers that tell the oncologist which mutation is present, if any. Most gene mutations are caused by environmental factors that can change your DNA, such as exposure to ultraviolet radiation, cigarette smoke, or other substances that are known to increase your risk for developing cancer. DNA can also change because of a mistake made when it tried to repair itself. These mutations are called acquired mutations and were not inherited from your parents.

Treating cancer-based on your genes, and any mutations that are detected, is called "personalized medicine" or "precision medicine." Genomic testing is a key part of precision medicine. Two people with the same type of cancer, such as lung cancer, can have different genetic mutations resulting in different treatments that are known to work best.

What are the benefits of genomic testing?

Genomic testing can help your oncologist:

• Determine the number of tumor mutations or if it has clusters of mutations.

• Choose the cancer treatment that’s most likely to work best for you based on the results

• Identify the best order for treatments when more than one type of therapy is needed

• Spare you from getting treatments that aren't likely to help

• Avoid or lessen side effects of the treatments

• Improve your prognosis for a five-year survival

• Predict if you’re at a high risk or low risk for recurrent cancer

• Avoid additional treatment if you have a low risk for recurrence, or if you have a high risk, other treatments can keep cancer from recurring.

How is genomic testing done?

A sample of your cancer cells is removed and analyzed, typically as part of your biopsy if you have a tumor. If you have blood cancer, a blood sample is tested (called a liquid biopsy). Genomic sequencing is the process of analyzing DNA from a blood sample. Tumor cells can "shed" DNA, and the DNA circulates in the blood.

Other tests analyze genes. Your blood, saliva, or a small sample of skin are collected to provide a sample of healthy cells. Cancer cells are compared to healthy cells to find genetic mutations acquired during your lifetime. There can also be genetic mutations that are handed down from generation to generation. Most cancers are caused by acquired changes.

What is targeted therapy?

Targeted treatments (also called precision medicine) are being developed as a result of genomic testing. They target specific gene mutations or target new proteins that make cancer cells grow. Some treatments kill cancer cells; others work by blocking the cell's signals that help cells multiply and spread (metastasize). Targeted therapies have been developed to treat breast cancer, chronic myeloid leukemia, colorectal and lung cancers with many more planned through clinical research.

What are biomarkers and biomarker testing?

Your doctors may use unfamiliar terms when discussing your cancer, making it even more difficult to understand the complex process of genomic testing. Let's take a minute to clarify the terms you may hear that describe these new and still evolving treatments. Because more than 30 different terms are used by healthcare providers when discussing genomic testing, a national consortium of cancer experts and patients have adopted these two terms:

• "Biomarker testing," a broader term than genomic testing, means analyzing a patient's tissue or blood for specific mutations, tumor markers, or altered genes. It also looks for proteins made by genes that provide important information about cancer. Biomarker testing is the preferred term for testing for somatic (acquired) mutations. Biomarker testing does not include gene changes that were inherited from your parents.

Biomarker testing is being done to select treatments for patients who have non-small cell lung cancer, breast or ovarian cancer, colorectal cancer, or melanoma. Some cancer treatments (immunotherapies and targeted therapies) usually only work for people whose cancers have certain biomarkers.

Your doctors may use other terms for biomarker testing, including genomic testing, genetic profiling, tumor genetic testing, molecular testing, molecular profiling, somatic testing, or tumor subtyping.

• "Genetic testing for inherited mutations," is the term for people who have a cancer diagnosis, or a close relative with a diagnosis that's linked to genetic or inherited mutations. In these cases a specific genetic test is run to look for any mutations or hereditary syndromes that increase the likelihood of developing cancer.

Is genomic testing available for all types of cancer?

No, it's currently being used on a few cancers. However, research is rapidly expanding it to additional cancers.

There are many patients who don’t have any specific biomarkers when they go through genomic testing, and that’s OK. It simply points your oncologist in a different direction rather than spending time using targeted therapies that aren’t likely to work.

Getting cancer treatments that work best for each patient based on their biomarkers, or lack of them, will make it easier to slow the growth of cancer quickly. This is a huge leap forward for cancer patients everywhere, including right here in Florida.

The oncologists at Cancer Care Centers of Brevard will run biomarker tests for appropriate types of cancer to identify the right treatment plan for each patient. If you have been diagnosed with cancer, request an appointment with our cancer specialists located in Melbourne, Palm Bay, Merritt Island, and Rockledge. If you have already seen an oncologist but would like a second opinion, we are also happy to offer that service as well.

Categories: Clinical Trials