The Numbers Are Hard to Ignore

A UC San Diego study found a stark contrast in colon cancer survival rates: 15.5% mortality vs. 37.1% mortality within five years.

The research analyzed medical records from more than 6,800 colon cancer patients across the University of California health system, published November 12, 2025, and reported by ScienceDaily.

Patients on GLP-1 drugs — semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) — were less than half as likely to die compared to those not on the drugs.

Who Did This Research and How

The study was led by Raphael Cuomo, Ph.D., associate professor in the Department of Anesthesiology at UC San Diego School of Medicine and a member of the UC San Diego Moores Cancer Center.

His team pulled data from the University of California Health Data Warehouse — covering academic medical centers statewide, not a single hospital.

Researchers adjusted for age, BMI, cancer stage, and other health conditions. The mortality gap remained. The benefit held even after controlling for variables that might otherwise explain it away.

The effect was strongest in patients with severe obesity (BMI over 35), according to ScienceDaily. This suggests GLP-1 drugs may be countering the metabolic and inflammatory environment that makes cancer harder to treat in obese patients.

MSK Is Now Publishing in JAMA on This

Memorial Sloan Kettering Cancer Center — one of the most respected cancer institutions in the country — published research in JAMA Network in March 2026 directly linking overweight and obesity to roughly 10% of all new cancer diagnoses in the U.S.

For certain cancers, like endometrial and hepatobiliary (liver, bile duct, gallbladder), obesity accounts for up to 50% of cases.

MSK breast medical oncologist Dr. Sherry Shen said GLP-1 drugs "look to be promising in potentially reducing the number of people who are diagnosed with these obesity-related cancers."

Dr. Shen also published a study in August 2025 finding these drugs helped breast cancer patients lose weight during treatment — weight gain being a common side effect of breast cancer therapy that worsens cardiovascular outcomes.

She identified at least 13 cancer types linked to obesity: post-menopausal breast, colon, gastric, prostate, endometrial, and others.

Why Would a Diabetes Drug Fight Cancer?

GLP-1 receptors aren't only in the gut. They exist throughout the body — including in tissues involved in inflammation and metabolic signaling.

According to ZME Science, researchers believe GLP-1 drugs may be interrupting the conditions tumors need to thrive: chronic inflammation, high insulin levels, and metabolic dysfunction. These drugs appear to disrupt those environments.

Cuomo emphasized the results are "observational" and called for clinical trials before drawing firm conclusions. The mechanism is not yet proven. No one should be treating Ozempic as chemotherapy.

But the observational evidence continues to mount.

What Mainstream Coverage Is Missing

Most media coverage treats this as a weight-loss story with a cancer benefit. The broader picture is different.

A class of drugs originally developed for type 2 diabetes, then repurposed for obesity, may be reshaping outcomes across multiple disease categories — heart failure, liver disease, addiction, and cancer survival.

Fox News flagged the cancer-slowing angle. ScienceDaily and ZME Science explored the mechanism. MSK grounded it in oncology context. Few outlets are connecting the dots across all these findings and examining what they mean for drug funding, prescribing, and regulation.

Insurance coverage for GLP-1 drugs remains inconsistent. Medicare only recently began covering them for obesity under specific conditions. Many patients who could benefit — including cancer patients with obesity — can't access them or can't afford the out-of-pocket cost, which runs $800–$1,000+ per month without coverage.

The gap between what the science shows and what patients can actually get is significant. Washington has not approached this with the urgency the data warrants.

What This Means for You

If you or someone you know has been diagnosed with colon cancer and has obesity as a factor, this research warrants a conversation with an oncologist — specifically about whether GLP-1 therapy should be part of the treatment plan.

Clinical trials are not yet complete. These findings are observational. The mechanism is not fully confirmed.

When a drug cuts five-year cancer mortality by more than half in a study of nearly 7,000 patients, and a top cancer center simultaneously publishes in JAMA connecting obesity to 10% of all new U.S. cancer diagnoses, the medical establishment needs to act faster than usual.