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Beth’s Colorectal Cancer Story

Beth was in an exciting stage in her life一she had a new baby, a new home, and she had just started a great new job. Yet she found herself struggling with digestive problems, constantly feeling exhausted, bloated, and nauseous. The doctors she visited recommended diet changes and antibiotics, but her symptoms kept getting worse.

Finally, her GI specialist ordered a colonoscopy, a medical test that can detect abnormalities in the large intestine (colon) and rectum. Since Beth was only 31 years old, her doctors told her they didn’t expect to see anything. When she woke up from the procedure, her heart sank as she realized her nurse was struggling to make eye contact. She was told her doctor would be in to speak with her soon.

The colonoscopy had found a tumor in her colon. After additional testing, Beth was diagnosed with stage IIIB sigmoid colon cancer, which meant the cancer had already spread to her surrounding lymph nodes.

Beth was in shock. Instead of looking forward to her family’s future, she had to shift her focus to fighting cancer.

Everything else fades away and nothing else is important other than making sure you’re still here for your family. - Beth

Starting Treatment

A week after her diagnosis, Beth had surgery to remove the tumor and the surrounding lymph nodes, two of which were cancerous. She was relieved to learn that the cancer had not spread to any other organs. After surgery, she began standard-of-care chemotherapy (chemo) to reduce the risk of her cancer coming back.

Beth understood that she needed chemo, but was worried about how it could impact her ability to have another child. Her doctors told her that chemo could have prolonged effects on fertility一realistically, she may not be able get pregnant for years, if at all. “But I’m not done having babies,” Beth thought.

Fortunately, Beth found Dr. Anup Kasi, an oncologist at the University of Kansas who understood her concerns. With his support, Beth began to view chemo as a way to increase the chance that her cancer would not come back. While it could impact her chances of having another child, it would help make sure she was there for her son. She began her first chemo cycle in November 2019.

Struggling With Side Effects

Beth found chemo to be the most challenging part of her treatment. She struggled with severe side effects that made it difficult to complete daily tasks, including fatigue and neuropathy (nerve damage that can cause muscle weakness and pain). These adverse side effects persisted even after Dr. Kasi reduced her chemo dosage. “The neuropathy was the hardest thing,” she reflected. “You can’t drink anything cold. You can’t touch anything. It was the middle of winter, so going outside was really difficult.” At times, she struggled to lift her young son.

As Beth endured these challenges, the onset of the COVID-19 pandemic threw another curveball: chemo made her more vulnerable to severe infection. Most stage III colon cancer patients complete treatments for six months, according to standard-of-care recommendations for stage III colon cancer.1 However, at month four, she and Dr. Kasi decided to reevaluate chemo’s risks and benefits in light of the pandemic and her ongoing side effects.

Recent studies suggest that not all people with stage III colon cancer need a full six months of chemo to reduce their risk of recurrence, and that some patients could get the same benefit with less treatment.2

Surveillance with Signatera™

A component of Beth’s treatment was monitoring for early signs that some cancer might remain after her surgery. Her standard-of-care imaging and blood tests did not show signs of cancer, but Dr. Kasi wanted a more sensitive tool to help inform whether to halt or continue Beth’s chemo, since stopping earlier than six months would be outside of current guidelines.

"The standard tools that we use for monitoring…are good to a certain extent, but there has to be a sufficient amount of tumor activity for them to pick up [the cancer]. We needed something more precise and that’s when I decided to utilize Signatera™." - Dr. Anup Kasi, Beth’s oncologist

Dr. Kasi decided to use the Signatera™ Residual Disease Test, Natera’s personalized circulating tumor DNA (ctDNA) test for monitoring molecular residual disease (MRD). MRD refers to small fragments of cancer that may be present in a person’s bloodstream. Studies have shown that people who have detectable MRD after surgery are more likely to have a recurrence of their cancer.4

Signatera™ is designed using a small tissue sample from a person’s tumor. This sample is sequenced to create a personalized test to detect the presence of ctDNA一tiny fragments of DNA released by cancer cells. Once this test has been custom-designed, a blood draw can be used to test for signs of MRD every few months. Since Signatera™ is built for each person’s unique tumor, it is sensitive enough to detect microscopic traces of residual disease一even before it is detectable on scans.4

Supporting Critical Decisions With Signatera

Beth received her first Signatera™ test after four months of chemo and results showed no ctDNA was detected in her blood. Since these results were consistent with her CT scans and other labs, Beth and Dr. Kasi made the decision to discontinue chemo, two months earlier than the intended original treatment plan.

Follow-up Signatera™ test results continued to be negative for ctDNA. Beth’s imaging and other labs also showed no signs the cancer was recurring. Getting tested regularly and receiving consecutive negative Signatera™ results gave Beth the confidence to dream about her future again.

Expanding Her Family

Six months after discontinuing chemo, Signatera™, a colonoscopy, and a CT scan all indicated that the cancer had not returned. Beth felt ready to get back to the life she’d been planning before her diagnosis. Near the end of 2020, just over a year after starting her colon cancer journey, Beth and her husband were able to conceive again.

As soon as Signatera™ came back negative, that’s when I really felt like... Maybe we can start trying to have a baby. - Beth

Under the guidance of Dr. Kasi and her OBGYN, Beth continued to use Signatera™ to monitor for MRD throughout her pregnancy, allowing her to avoid radiation from CT scans.* In July 2021, she gave birth to a healthy baby boy.

As Beth and her family embrace their life together, she continues to keep an eye out for recurrence with serial Signatera™ testing, along with standard tests recommended by her doctor.

If future Signatera™ tests do detect any ctDNA in her bloodstream, she and Dr. Kasi may have an early opportunity to formulate a game plan, which could include additional testing or other treatment intervention. In a clinical study published in the Journal of the American Medical Association in 2019, Signatera™ was shown to detect colorectal cancer recurrence up to 16.5 months ahead of CT scans.4

Today, Beth remains free from cancer recurrence. She is grateful for her health and her family, and is hopeful for the future.

Signatera™ gave me the freedom to just feel that everything is going to be okay. I am healthy again, and we can actually move on, just enjoying being together. - Beth

To learn more about Signatera™ in colorectal cancer, click here.


Signatera™ has been developed and its performance characteristics determined by the CLIA-certified laboratory performing the test. The test has not been cleared or approved by the US Food and Drug Administration (FDA). CAP accredited, ISO 13485 certified, and CLIA certified. © 2022 Natera, Inc. All Rights Reserved.


1Sobrero A, et al. The hard road to data interpretation: 3 or 6 months of adjuvant chemotherapy for patients with stage III colon cancer? Ann Oncol. 2018;29(5):1099-1107.

2Taieb J, et al. Adjuvant chemotherapy for stage III colon cancer. Cancers (Basel). 2020 Sep;12(9):2679.

3Chin R, et al. Detection of solid tumor molecular residual disease (MRD) using circulating tumor DNA (ctDNA). Mol Diagn Ther. 2019 June;23(3):311-331.

4Reinert T, et al. Analysis of plasma cell-free DNA by ultradeep sequencing in patients with stages I to III colorectal cancer. JAMA Oncol. 2019;5(8):1124-1131.

*Signatera™ is contraindicated for use during pregnancy. Beth’s choice to use Signatera™ was made through shared decision-making with her treating physician and family. No treatment recommendations are made or should be implied.