A silent tumor, precancerous polyps and the power of genetic screening

By Susan Murphy

Tammy LeDoux could never have imagined she had a tumor the size of a pineapple growing on her left ovary. Or that precancerous polyps were lurking in her stomach and colon.

"I never had any cramping. I never had any pain. I never felt anything hard or lumpy in my abdomen or down in my pelvic area. I never knew anything was there," says Tammy, an information technology analyst who lives in Wisconsin.

The surprising discoveries came after Tammy underwent genetic screening via the Mayo Clinic Center for Individualized Medicine, which revealed she has Lynch syndrome. The disorder is associated with an 80% risk of colorectal cancer and a 50% risk of uterine and endometrial cancer.

"I honestly feel like knowing these genetic results has saved my life," Tammy says.

Tammy's experience mirrors that of many other patients who, prior to participating in the Center’s DNA sequencing research study, called Tapestry, were unaware of their disease risk.

Overall, nearly 1.3 million Mayo Clinic patients like Tammy were invited to join Tapestry, which screened for three hereditary conditions: familial hypercholesterolemia (hereditary high cholesterol), hereditary breast and ovarian cancer (BRCA1 and BRCA2), and Lynch syndrome. Of those, roughly 100,000 chose to participate.

Based on existing literature, the study anticipated nearly 2% of participants would receive a positive result.

"What keeps me up at night is the fact that 1.2 million patients chose not to participate in the study, and this means around 20,000 of them likely have an undiagnosed hereditary risk or condition when considering the 2 percent rate of a positive result," says Konstantinos Lazaridis, M.D., the Carlson and Nelson Endowed Executive Director for Mayo Clinic's Center for Individualized Medicine. "We need to do a better job of educating people about the value of genetic screening for rare but preventable conditions," he says.

Dr. Lazaridis says Mayo Clinic is advancing the idea of bringing genetic screening to routine patient care to help identify patients at high risk for cancer and other diseases, enabling earlier screening and mitigating the risk of cancer, the need to use expensive and limited therapies for advanced disease, and reducing premature deaths.

Beyond disease prevention, Mayo Clinic researchers are investigating volumes of Tapestry data to drive forward medical discoveries that enhance novel diagnostics and treatments.

Launching the Mayo Clinic Early Onset and Hereditary GI Cancers Program

In tandem with these efforts, Niloy Jewel Samadder M.D., and Christina Wu, M.B., B.Ch., M.D., physician scientists in the Mayo Clinic Comprehensive Cancer Center, launched a new program in February 2024 to address the significant rise of colorectal and other gastrointestinal cancers in young people.

The Mayo Clinic Early Onset and Hereditary Gastrointestinal Cancers Program is dedicated to patients under the age of 55 who are diagnosed with colorectal, gastric, esophageal, liver, bile duct or pancreatic cancer.

This patient-centric program creates an integrated network of services involving gastroenterology, gynecology, oncology, colorectal surgery, infertility, pathology, genetics and adolescent and young adult specialists.

In 2022, Mayo Clinic's three campuses in Arizona, Florida and Minnesota reported over 2,000 newly diagnosed cases of gastrointestinal cancers among people under the age of 55. The marked rise in young-onset colorectal and other gastrointestinal cancers underscores a pressing health issue. The new program aims to provide accelerated access to top-tier care.

Dr. Samadder emphasizes that encircling patients with a multidisciplinary team of specialists will help provide the best possible outcomes.

"Our goal is to put the patient at the center of a collaborative framework of experts from diverse fields working seamlessly together," says Dr. Samadder, a Mayo Clinic gastroenterologist and cancer geneticist.

"The program also incorporates translational discoveries such as immunology and cancer evolution, as well as a clinical trial menu, research initiatives and a multi-omics approach that connects to a patient's unique biological datasets,” Dr. Samadder says.

Tammy’s journey to the Tapestry study

Tammy’s initial motivation to participate in the Tapestry DNA research study was her curiosity about her ancestral heritage — another aspect of the study.

Upon receiving her genetic screening results, Tammy's team of genetic counselors and physicians moved quickly to educate her on Lynch Syndrome and help her schedule various screenings, including a colonoscopy, urine biopsy and ultrasound.

These screenings uncovered 10 polyps in her colon and stomach, some with precancerous characteristics, and two concerning moles on her skin. Soon after, Tammy made the proactive decision to undergo a hysterectomy to reduce her cancer risk. It was during this procedure that surgeons discovered and removed the sizable benign tumor.

"I couldn’t believe it. I’m beyond grateful," Tammy says. "I've been through the ringer, but now I have peace of mind knowing I've reduced my risks for cancer, and I can go in every couple years to check for any new polyps."

Mayo Clinic is dedicated to shaping a future where cancers and other diseases can be prevented altogether, or identified at earlier stages, allowing for more precise treatment by a collaborative team of specialists.

Learn more

Learn more about Lynch syndrome and clinical trials.

Join the Cancer Support Group on Mayo Clinic Connect, an online community moderated by Mayo Clinic for patients and caregivers.

Also, read these articles:

• New gene markers detect Lynch syndrome-associated colorectal cancer
• Why millennials should know colon cancer symptoms
• 9 common questions about genetic testing for cancer
• Is a cancer clinical trial right for me?
• Dear Mayo Clinic: Genetic counseling after cancer diagnosis
• Dear Mayo Clinic: What is the benefit of visiting a genetic counselor?

A version of this article was originally published on the Mayo Clinic News Network.