Eligible patients filled at least two prescriptions within their first year of treatment. Follow-up began one year after treatment started, a standard lag designed to exclude cancers that were likely already present but undiagnosed when treatment began.

The researchers calculated country-specific hazard ratios and incidence rate differences, then pooled them across the three countries using a fixed-effects meta-analysis. They also ran extensive sensitivity and supplementary analyses to test whether the findings held up under different assumptions.

Patient characteristics were well balanced between the semaglutide users and the matched control cohort. Among semaglutide users, median age ranged from 59 to 62 years, with mean follow-up after the 1-year lag of 1.40 to 1.85 years.

What did the data show?

The researchers recorded 131 pancreatic cancer cases among semaglutide users and 123 among active comparator users, across 167,399 and 140,306 person-years of follow-up, respectively.

Incidence rates were similar between the groups in every country:

• Semaglutide users: 0.64 to 0.91 cases per 1,000 people per year
• Active comparator users: 0.80 to 0.98 cases per 1,000 people per year

No single country showed an increased risk. The country-by-country hazard ratios were:

• Denmark: 1.00 (95% CI 0.66–1.51)
• Sweden: 0.82 (95% CI 0.56–1.22)
• Norway: 0.91 (95% CI 0.55–1.51)

The pooled absolute risk difference was −0.10 per 1,000 person-years (95% CI −0.31 to 0.10) — essentially zero.

The researchers also looked for cumulative effects, since a cancer-causing drug would be expected to show higher risk at higher doses or longer use. They found none: the pooled hazard ratio for high dose was 0.74 (95% CI 0.40–1.40), and for long duration 0.79 (95% CI 0.37–1.69). Sensitivity and supplementary analyses consistently showed no increased risk.

What are the study's limits?

A few caveats deserve mention. The findings were presented at a conference and have not yet appeared in a peer-reviewed journal. The average follow-up of roughly 1.40 to 1.85 years after the lag period is relatively short for a cancer that can take many years to develop, so the results cannot fully rule out long-latency effects. The study also covered patients treated for type 2 diabetes, so the results may not automatically extend to people using semaglutide primarily for weight management.

That said, the study's scale, its three-country registry base, and its consistent results across dose, duration and country analyses give it substantial weight.

Pottegård concluded: "This comprehensive study, using nationwide registry data from three countries, found no increased risk of pancreatic cancer with use of semaglutide as compared to use of other glucose-lowering drugs used at a similar stage as semaglutide in the treatment of T2DM."

He added: "This conclusion was supported by the absence of a cumulative dose-response or dose-duration effect, consistent findings in the individual countries and in a wide range of supplementary and sensitivity analyses. These findings also align with current external evidence and thus further strengthen the evidence that semaglutide does not increase the risk of pancreatic cancer."