After primary treatment for prostate cancer, 1,25-dihydroxyvitamin D3 (calcitriol) effectively slows the rise of prostate specific antigen (PSA). Investigators report on an open-label, nonrandomized, pilot trial in seven men that evaluated whether calcitriol therapy is safe and efficacious for early recurrent prostate cancer. Serum PSA levels have been shown to be a reliable surrogate marker of prostate cancer growth and, therefore, a decreased rate of PSA rise should correlate with decreased tumor growth.
The PSA levels in the study's subjects began to rise after primary treatment with radiation or surgery. These individuals were asymptomatic at the time of enrollment and their physicians did not want to initiate androgen ablation therapy.
The patients were therefore treated with calcitriol for 6 to 15 months. Daily doses of calcitriol for patients in this study depended on individual calciuric and calcemic responses. Multiple regression analysis indicated a statistically significant decreased rate of PSA rise in six of seven patients. The researchers report, "Of our seven patients, the response to calcitriol therapy was major in one, moderate in three, and minor in two."
Am J Urol June, 1998;159:2035-204
Dr. Mercola's Comment:
Prostate cancer is the most common in men. This is the first report I am aware of that highlights the usefulness of activated vitamin D to treat prostate cancer. I have not used this treatment before but plan on offering to patients after I retrieve the article.