Genome Testing for Cancer: Revolutionizing Diagnosis and Treatment

Researchers are constantly learning more about how our genes interact with each other and the environment in ways that affect our health. The study of all our genes, also known as the human genome, is called genomics.

With the rise in popularity of genetic testing, including home kits, information about our physical characteristics, current health, and health predictors is more available than ever. While conventional genetic testing can give helpful insights about inherited traits and hereditary diseases, genome testing provides a more comprehensive picture of how all of our genetic make-up works together and its unique impact on our personal health.

Here, we cover the basics of genome testing, how it differs from genetic testing, and how this technology is revolutionizing cancer diagnosis and treatment.

Genomics vs. Genetics

You may be more familiar with genetics, which refers to the study of individual genes. Traditionally, genetics has been more focused on providing insights about inherited traits and hereditary diseases. Genomics, on the other hand,is a subcategory of genetics and refers to the study of the entire genome – meaning, all the genes in your body – and how those genes interact with each other and their environment.

What is genome testing?

Genome testing analyzes the genome, which can tell us how changes across our genes might impact the way our cells grow, function, and divide.

Due to how extensive it is, genome testing can be used to investigate different types of cancer and other rare diseases. Unlike conventional genetic testing, genome testing for cancer can analyze cancer cells to see how variations in your unique genetic information might influence your cancer’s expression and progression.

Even common cancers might not develop the same way for every person, so genome testing can help your healthcare provider better understand your prognosis and develop the best cancer care plan for you.

Genome testing is also sometimes called genomic testing or biomarker testing.

Why is genome testing important for cancer?

Genomic testing for cancer has numerous benefits, including:

• More precise insights: Different types of cancers have different growth rates and differing likelihoods of spreading to other areas. The same type of cancer can also impact people differently.
  With such a range of possibilities, genomic testing can provide more precise insights about your specific cancer so that you and your provider can better understand how it is developing and how it might respond to certain treatments.
• Personalized treatment guidance: Whole genome sequencing uncovers unique biomarkers and detects genetic changes that might influence the rate of your tumor’s growth. This enables your provider to develop a treatment plan based on your tumor’s specific genomic profile. This is known as precision oncology¹, which makes personalized treatment options possible.
• Cancer prognosis: WGS illuminates certain patterns in your genome that can help your health care provider better understand your prognosis and anticipate how certain treatments might work for your cancer type. This can help rule out treatments that may not be effective for you so you can avoid unnecessary side effects.
• Clinical trial opportunities: Genomic testing uses your biomarkers and unique health information to identify active clinical trials for which you might be eligible. This may increase the breadth of treatment options available to you.

Do I need genome testing for my cancer?

People with certain types of cancer may benefit from genome testing after being diagnosed. Genome testing can provide important information about your cancer, including how quickly it might grow. It can also help determine which treatment types may work best for you.

Having this information can lead to more informed care decisions and eliminate unnecessary treatments. It can also help you know whether you qualify for certain clinical trials.

Why does genome testing sometimes lead to other genetic testing?

Some genome test results may find genetic changes that you were born with that can lead to a higher risk of developing cancer or other diseases. These gene changes are called inherited or germline variants and could also impact your family members.

When this occurs, your healthcare team may recommend genetic testing for an inherited genetic variant. Some genetic tests also look for somatic changes to your genes (changes that developed at some point in your life after birth), as well as hereditary cancer risks. This is called a paired-somatic test. Paired-somatic testing can identify changes in your DNA that have been present since birth (germline changes) as well as changes that occurred randomly during your life (somatic changes). By utilizing a paired-somatic testing approach it can potentially reduce your need for further testing down the line.

How does genome testing work?

Like many medical tests, genome testing starts with the collection of a biological sample. Genome testing for cancer often involves a tumor biopsy or liquid biopsy samples.

Once the cancer cells are extracted from the sample, they are then studied more closely and analyzed through DNA sequencing². This complex process is made possible by a technology called next-generation sequencing (NGS), which enables the analysis of large volumes of data – such as that involved with genomic profiling – quickly.

Genomic testing can be carried out in a variety of ways. Whole genome sequencing (WGS) is the most comprehensive form of genomic testing, and it involves the analysis of nearly all of your DNA³ to identify genetic variations that may be related to your diagnosis.

DNA changes detected by WGS could be inherited (changes known as germline variants) or could have developed at some point in your life after birth (known as acquired or somatic variants). The comprehensive nature of this test increases the likelihood of finding useful clinical information to identify the most effective cancer treatment for you.

WGS for cancer can potentially be used to:

• Diagnose different cancer types, especially highly hereditary cancers like breast cancer and colorectal cancer
• Conduct tumor profiling to see how fast your tumor is growing and to identify what may be contributing to your tumor’s growth genetically
• Provide information about where your cancer started or where a secondary tumor originated
• Analyze how active certain genes are in your cancer tumor
• Predict how your cancer might act or respond to certain treatments
• Determine whether your family members may have an inherited cancer risk to inform the timeline of their cancer screenings

Genome testing vs. conventional genetic testing: key differences

Genetic testing can provide helpful information about irregularities in your genes that might indicate whether you are at an increased risk for certain types of hereditary diseases. However, conventional genetic tests such as target panel tests only look at less than 0.1% of your genome, which can result in a lot of unanswered questions.

In comparison, genomic testing looks at 99% of the human genome – including both coding and non-coding regions of the genome to further investigate how the genes that make up your cancer are behaving. This is important because even non-coding DNA⁴, which was once thought of as “junk,” can provide important information about which genes are turned “on” and “off” and why.

Genome testing: what to expect

Taking a genomic test is a straightforward process. Your genomic test can be ordered through consultation with your healthcare provider. Or, if you prefer, you can also initiate the process through Inocras. Either way, there are a few basic steps:

• Order your genomic test: A genomic test is sometimes ordered by your provider to help diagnose certain cancers or diseases and to investigate appropriate treatment options. Genomic testing has also become more accessible directly to patients through companies like Inocras.
• Schedule your sample collection: Genomic testing can be conducted with a blood and/or tissue sample, depending on the type of disease being studied. Your blood sample may be collected in a lab or in the comfort of your own home with the help of a mobile phlebotomist. If you order the test for yourself, your test provider will likely work with your care team or pathologist’s office to collect your cancer tissue sample.
• Get your results: With some genomic testing, your report will be made available through your provider who can walk you through the findings. Depending on your test provider, you may also receive access to a genetic counselor. Genetic counselors can help you understand your results and answer genetics-related questions.
• Determine a path forward: Genomic testing can provide helpful information about how your cancer is developing and what to try next. With the support of your results, your provider, and the input of a genetic counselor, you can play an active role in refining your treatment plan based on any relevant findings.

Get cancer clarity with genome testing

Genomic testing is transforming how cancer is diagnosed and treated. It enables a greater understanding of how gene changes impact your cancer’s growth and treatment response. Genomic testing supports greater clarity about your condition and could potentially lead to more personalized care options.

Unlock more information about your cancer with insights from Inocras’s genomic test for cancer patients. In addition to comprehensive testing and easy-to-read reports, CancerVision will help match you with any clinical trials you may be eligible for. You’ll also receive access to genetic counseling at no extra cost.

Transform your uncertainty into clarity. Order your CancerVision test.

References:
1. “Precision Oncology.” National Institutes of Health (NIH), 16 Nov. 2023,
www.nih.gov/about-nih/what-we-do/nih-turning-discovery-into-health/promise-precision-medicine/ precision-oncology.
2. “Advanced Genomic Testing: How It Works and Benefits.” City of Hope,
www.cancercenter.com/treatment-options/precision-medicine/advanced-genomic-testing.
3. Costain G, Cohn RD, Scherer SW, Marshall CR. Genome sequencing as a diagnostic test.
CMAJ. 2021 Oct 25;193(42):E1626-E1629. doi: 10.1503/cmaj.210549. PMID: 34697096; PMCID: PMC8562981.
4. What Is Noncoding DNA?: MedlinePlus Genetics.
medlineplus.gov/genetics/understanding/basics/noncodingdna.