How Does Genome Sequencing Work

In the evolving field of cancer research, scientists are continually searching for methods to make cancer treatment more effective. Genome sequencing is one of those methods, falling under the umbrella of precision medicine.

How does genome sequencing work?

Your DNA contains a genetic code that gives the cells in your body instructions to grow, divide and reproduce. These instructions affect everything from your hair color and blood type to your risk of developing certain diseases. In a person with cancer, something has interrupted those instructions and caused the cells to mutate.

Genome sequencing is the process of identifying those mutations by evaluating each DNA molecule. Think of it like a biological spell check. When scientists sequence DNA, they examine the entire genetic code looking for “spelling errors.” The errors they find can help identify targeted therapies to treat that specific error.

Providers and patients should decide together whether genome sequencing is appropriate. You can discuss genetic counseling with your oncologist during your consultation.

What should I consider?

Medical Necessity

Genome sequencing is currently most beneficial for people who have not had success with other traditional cancer treatments. Some types of cancers, such as Hodgkin’s lymphoma, are highly treatable, and genome sequencing is usually not necessary to identify a course of treatment that works.

Additionally, not all cancer cells have the same mutation, so an FDA-approved targeted therapy may not be successful for everyone—even if they have the same type of cancer. Some targeted therapies are well documented for treating specific cancers (e.g., breast cancer, melanoma, lung cancer), so if you have one of these cancers, genome sequencing may be beneficial to see if you have the mutation that these targeted therapies affect.

Insurance Coverage

Medicare covers FDA-approved tests for patients with advanced cancer, but because genome sequencing is not yet a standard component of cancer care, many insurers will not cover the cost of the test or the treatment without sufficient evidence that it is necessary.

Lack of insurance coverage does not mean you cannot do genome sequencing; it will just be more costly. Patients may also have the option to be part of a clinical trial, which often covers some or all of the associated costs.

Cost

The cost of genome sequencing varies based on the kinds of testing you get, but it can range from $1,000 to over $10,000. It’s important to remember that these costs are for only the genome sequencing, not the targeted therapy. The cost for these therapies are roughly $5,000 to $10,000 per month and may cost even more for therapies used to treat rare diseases.

Discuss the benefits and risks of genome sequencing with your healthcare provider in detail. He or she can help determine whether the benefits of genome sequencing outweigh the costs in your unique situation.

Genome sequencing is a very personal decision that has the potential to give healthcare providers more information about treatments that are available for their patients. These tests can be beneficial in choosing which therapy to provide, but there is no guarantee that the therapy will work. Include your support system in this decision and make sure you understand your options.