In Houston, Texas, a poignant memory marked Dr. Stacy Norton’s early life—losing her mother to colon cancer at just seven years old. This personal history of aggressive familial tumors inspired Norton to take a step forward decades later. She joined efforts testing a groundbreaking vaccine with hopes of shielding herself and her children against cancer’s relentless grip.
Dr. Norton is among approximately 1 million Americans living with Lynch syndrome, a genetic predisposition inherited from parents that significantly elevates the risk of colorectal cancer and other malignancies. As a preventative measure, those affected endure frequent screenings, often subjected to annual colonoscopies, aimed at detecting and removing precancerous polyps before they progress.
Innovations in preventive medicine are now advancing, with scientists working on vaccines that would teach the immune system to fend off emerging colon cancers associated with Lynch syndrome before they escalate into tumors. Currently, three potential vaccines are under development, with two undergoing early clinical trials in the United States and another embarking in the United Kingdom.
The vaccine that Norton assisted in testing has shown such potential that Dr. Eduardo Vilar-Sanchez from MD Anderson Cancer Center anticipates the commencement of a more extensive study early next year.
“It gives me hope,” expressed Norton, 59, associated with Houston Methodist Willowbrook Hospital. Having survived a Lynch-related cancer herself and with two children in their twenties who have inherited the mutation, she eagerly awaits the vaccine’s fruition. “If successful, my children might not have to undergo annual colonoscopies for the rest of their lives,” Norton envisions optimistically.
Lynch syndrome is caused by an inherited genetic mutation
Everyone has what are called mismatch-repair genes, which are essentially spellcheckers to help fix DNA mistakes that can occur when our cells multiply. With Lynch syndrome, one of those genes can’t do its job properly, making it harder for the body to stop a buildup of abnormalities that can lead to tumors, often before age 50.
Colorectal cancer
Norton knew some of her mother’s relatives had also experienced colon cancer, but she was in her 40s before a gene test confirmed she has Lynch syndrome. She switched from every-so-often to yearly colonoscopies. As an obstetrician/gynecologist familiar with other Lynch risks, Norton also decided to have a precautionary hysterectomy. Surgeons discovered early-stage cancer in her removed uterus.
Possible vaccines to stop gene-caused cancer
Today there are two cancer-preventing vaccines,
“Can we even further stimulate the immune system” to keep up with Lynch syndrome-spurred tumor formation, asked Dr. John Marshall, a Georgetown University oncologist and adviser to the Colorectal Cancer Alliance who wasn’t involved with the study. “This early paper suggests that yeah, maybe we can.”
For the first time since 2014, Norton’s own colonoscopies one and two years after vaccination were polyp-free. She’s also part of a subset of study participants given a booster shot a year later; more data on that is expected this fall.
Oxford University researchers are beginning initial testing of a similar approach to attack Lynch-spurred precancers, a vaccine made by Massachusetts-based Moderna using the mRNA technology behind its COVID-19 shot.
And scientists are awaiting results from a slightly larger study comparing California-based ImmunityBio’s Tri-Ad5 vaccine, which flags some different cancer markers, to a placebo.
Is Lynch syndrome tied to the rise in young adult colon cancer?
About 158,000 people are diagnosed with colorectal cancer in the U.S. each year, most of them over 50.