How one local mom uses a blood test to monitor cancer recurrence

Cancer survivors may be able to monitor if their cancer comes back with a blood sample.

Stephanie Reetz from Alvin is a mom of two. She teaches her kids from home, plays with them, and after being treated for colon cancer, she doesn’t take any of it for granted.

Even though her surgery went well, and she’ll continue to be monitored every few months, the time in between scans makes her nervous. So, she found a blood test that might be able to tell her if the cancer has come back.

“It’s a circulating tumor DNA test where they can take a blood sample and compare it to your tumor to see if there’s anything in your blood left,” Reetz explained.

The test she uses is called Signatera.

Vice President of medical affairs at Natera Dr. Alex Aleshin said while liquid biopsies have been around for years, theirs are ultra-sensitive.

“We start by sequencing the patient’s tumor to find the unique fingerprint which we then use to design a personalized test. Once that test is designed, it’s a simple blood draw to make sure that the patient remains cancer-free and also to detect recurrence early,” Aleshin said. “So, a unique test is created for each patient, and that allows the test to look very, very deeply into the plasma at these little pieces of DNA. Once the test is created, it never has to be re-designed, all you have to do is provide a plasma sample.”

Reetz can provide the sample from the comfort of her home.

“The package gets FedEx to you overnight. I just got that in the main, and set it on the counter and the next day the lady shows up and takes a sample and goes along with it. So it’s been really cool!” Reetz said.

The idea is amazing but cancer researchers say there are limitations.

For example, in a report published last month, only five of 15 patients who developed recurrent cancer were first detected with Signatera.

“Everybody agrees that more studies need to be done. This is a fundamentally life-changing technology but that needs to be rigorously studied and examined,” Aleshin said.

There is at least one local study happening at MD Anderson.

For Stephanie, she considers this an additional monitoring tool, not a replacement for scans.

The cost will be determined by your insurance provider but Aleshin said many patients pay $0.