Overview
- An Annals of Internal Medicine meta-analysis pooled 48 placebo-controlled randomized trials with 94,245 participants and a median follow-up of about 70 weeks.
- Researchers found with moderate certainty that risks for breast, kidney, thyroid, and pancreatic cancers were unchanged with GLP-1 therapies.
- Evidence for eight other obesity-related cancers was low certainty, and the effect on gastric cancer risk was described as very uncertain.
- Most trials were not designed to assess cancer outcomes, prompting calls for longer-term, cancer-focused studies to detect delayed effects.
- The trials evaluated FDA-approved agents such as semaglutide, dulaglutide, and tirzepatide, and regulators continue to advise caution for people with a history of medullary thyroid carcinoma.