The International Agency for Research on Cancer classifies aspartame as possibly carcinogenic to humans based on limited evidence.

Study: Aspartame Promotes Ovarian Cancer Progression: A Multi-omics Study Integrating Mendelian Randomization, Network Toxicology, and In Vitro Validation.

This study found that aspartame might help ovarian cancer grow by affecting certain genes in cells, which adds evidence that aspartame could possibly cause cancer — just like the cancer agency said.

Study: Molecular Mechanisms of Aspartame-Induced Kidney Renal Papillary Cell Carcinoma Revealed by Network Toxicology and Molecular Docking Techniques

This study found that aspartame might interact with genes and proteins in the body in ways that could lead to a rare type of kidney cancer, which helps explain why scientists think it might be linked to cancer—even though it doesn’t prove it causes cancer in people.

Study: Lack of Genotoxic and Carcinogenic Potential for Nonsugar Sweeteners: A Review of Animal and Mechanistic Evidence

This study looked at whether aspartame causes cancer in animals and cells, and found no proof it does — which goes against the idea that it might cause cancer in people. So it doesn’t support the claim that aspartame is possibly carcinogenic.