Heather Candrilli, 36, a mother of two, is battling metastatic colon cancer—underscoring the urgent need for education, research, and advocacy for young adults facing rising rates of the disease.
Her journey began two years ago with persistent abdominal bloating and rectal bleeding. “I had just delivered my son and assumed the symptoms were postpartum related,” she recalls. Even during a visit to urgent care, she mentioned the bleeding and was told by a clinician, “It’s probably just from internal hemorrhoids.” Over the following year, her symptoms worsened.
After speaking with her physician, an ultrasound and colonoscopy confirmed that Candrilli had colon cancer that had already spread to her liver.
Heather has completed 21 rounds of chemotherapy and had the tumor surgically removed from her colon. However, her liver tumors remain. She’s now on the liver transplant list—awaiting a donor match and funds to cover her medical costs—the next hopeful step toward becoming cancer-free.
What Causes Colon Cancer in Young Adults?
“Scientists are especially motivated to find the cause of colon cancer because its incidence is rising—particularly among younger adults who traditionally haven’t been considered high-risk,” said Dr. Austin Chiang, gastroenterologist and author of Gut: An Owner’s Guide. While some cases may be linked to genetic mutations, many, like Candrilli’s, are not. She has no family history of colon cancer and tested negative for genetic mutations.
Scientists are now exploring how the gut microbiome—the trillions of bacteria and other microorganisms that live in our digestive system—may influence cancer risk. These microbes help digest food, regulate the immune system, and in some cases, produce toxins that interact with our bodies in unexpected ways.
“Interactions with gut bacteria might be playing a bigger role than previously thought,” adds Dr. Chiang.
Emerging research supports this hypothesis. A recent Nature study highlights colibactin, a toxin produced by certain gut bacteria, like E. coli, which may damage DNA in colon cells and contribute to cancer development.
“Screening and modifiable lifestyle factors remain essential methods of colorectal cancer prevention,” said Dr. Angella Charnot-Katsikas, Clinical Pathologist and expert in molecular genetics at Loyola University Medicine. “But the Nature article shows that microbiome-derived ‘genotoxins’ may initiate cancer, even without traditional risk factors,” Dr. Charnot-Katsikas adds. She explains that researchers used whole-genome sequencing on 981 colorectal cancer genomes and linked specific DNA “signatures” to colibactin-producing bacteria. She says, “colibactin can leave a permanent ‘fingerprint’ in the colon that may induce cancer.” While these findings are compelling, she adds, “we still don’t know the cause of most early-onset colorectal cancers not tied to inherited genes.” And while the Nature paper made a major contribution, she awaits more research before these findings alter clinical strategies.
Prevention and Early Detection of Colon Cancer
Until then, early detection remains vital. Dr. Chiang shares, “the best place to start is with a gastroenterologist, especially if there’s a family history. Screening is crucial, and guidelines now recommend beginning regular colon cancer screening at age 45.” He also recommends resources like the American Cancer Society or the National Cancer Institute.
Screening at age 45 is an improvement from the previous recommendation of 50. Yet the lowered age still overlooks people like Candrilli—and thousands of others—diagnosed with advanced colon cancer before age 45. New York State Senator Jessica Scarcella-Spanton has introduced a bill that would lower the colorectal cancer screening age to 35. While the change would apply only to New York residents, Scarcella-Spanton says legislation passed in her state “could put pressure on other states” to follow suit. If passed, her bill would require insurance companies to cover costs of colorectal cancer screening starting at 35.
Insurance coverage is critical; under current policies, Candrilli had to pay $500 out of pocket for her colonoscopy—an amount that could deter some patients from seeking care. Lowering the screening age could also help shift public perception: colon cancer is no longer just a disease of the elderly.
For Candrilli, her hope is not only to heal—but to help young adults recognize symptoms of colon cancer early. “If you don’t know what cancer symptoms are, unfortunately you may be incorrectly deterred,” she adds. She urges patients to advocate for themselves. “Don’t brush off small symptoms. If you have rectal bleeding or bloating after eating small meals, this isn’t normal. You aren’t supposed to feel mediocre. You are supposed to feel good.”
