Is there any relationship between aspartame and cancer or tumor formation?

The American Cancer Society, the National Cancer Institute and the FDA have investigated the allegation regarding aspartame and human brain tumors and concluded that aspartame does not increase the incidence of brain tumors or cause cancer.

To test the link between aspartame and tumor formation, approximately 100 animal studies were conducted prior to its 1981 FDA approval. In some FDA studies, animals received huge amounts of aspartame (more than 1,000 cans of diet soft drink) for up to two years. No increase in brain tumors or any other type of tumor occurred, nor were there any other safety concerns in those animals. In addition to the scientific evidence that shows no relationship between aspartame consumption and tumor formation, there is no physiological reason why aspartame would cause cancer. Because it never enters the bloodstream, it cannot travel to essential organs, including the brain. When aspartame is digested, the body handles the amino acid components in the same way it handles them from other food sources.