Folic Acid Promising as Anti-Cancer Agent

Folic acid supplements may prevent cancer progression and promote regression of disease, according to a new study.

Published in the July 15, 2006 issue of the journal Cancer, the small study found that 31 of 43 patients with precancerous laryngeal lesions called leucoplakia demonstrated 50% or greater reduction in the lesion size after six months of taking folate supplements. In 12 of 31 responders, there was no evidence of the original lesion. Folate levels in the patients' blood also increased considerably from baseline while homocysteine levels decreased significantly. This study provides validation to support the hypothesis that folate insufficiency is a risk factor for cancer progression.

Folate deficiency is the most common vitamin deficiency in the United States. Folate is a naturally occurring B vitamin (B-9) found in abundance in fresh vegetables and fruits. Folic acid is its more stable synthetic form found in dietary supplements and fortified foods. At the biochemical level, folate is incorporated into coenzymes that are essential in facilitating a number of reactions in nucleic acid and amino acids metabolism. Some of which are crucial to healthy living, such as DNA synthesis, DNA repair, and converting homocysteine to methionine. The latter is especially critical because excess homocysteine is tied to chronic health problems, such as cancer and cardiovascular disease.

Animal and human studies have increasingly demonstrated associations between folate deficiency, serum homocysteine elevations, and a variety of cancers. Some studies have suggested that folate supplementation or at least a high folate dietary intake may protect against some cancers. This body of evidence suggests folate to be an effective chemopreventive drug. Other chemopreventive agents are being evaluated, and while the retinoids show the most potential, they are highly toxic.

Giovanni Almadori, M.D., from the Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Policlinico A. Gemelli (Rome, Italy) and coworkers have recently investigated the effectiveness of folic acid dietary supplementation to treat precancerous lesions and to prevent cancer.

The investigators enrolled 43 patients with untreated laryngeal leucoplakia and treated them with folic acid (5 mg, three times a day) and evaluated the progression of leucoplakia every 30 days for six months. After six months of treatment, 12 patients (28%) had complete resolution of their leucoplakia lesions; 19 patients (44%) had reduction of 50% or more in the size of their lesions and 12 patients (28%) had no response. Mean folate levels increased and mean homocysteine levels decreased significantly. There were no moderate or severe adverse events reported.

In comparison to another promising chemopreventive drug regimen that includes a retinoid, "Our complete response rate is lower than the one reported in a smaller population,” the authors reported in their article. However, they state that folate "is characterized by a lower grade of toxicity,” and there was no progression of disease.

These results suggest, according to the researchers, "folate supplementation, alone or in combination with other chemopreventive drugs, could effectively reduce the risk of progression in an already genetically altered mucosa, especially in patients with hypofolatemia.”



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