Growth of heterotopic LNCaP prostate cancer tumor in nude mice is not affected by dietary calcium.

Background: We attempted to provide experimental evidence linking increased dietary calcium to progression of prostate cancer, as suggested by some epidemiological studies, using a heterotopic prostate cancer nude mice model.

Methods: Twenty heterotopic LNCaP prostate cancer tumor bearing nude mice were randomly assigned to one of the four groups: (I) high fat/low calcium diet, (II) high fat and high calcium diet, (III) high fat diet fortified with Vitamin D3, and (IV) high fat and high calcium diet fortified with Vitamin D3. In addition to weekly animal weights and tumor size measurements, the serum prostate specific antigen (PSA), 25-hydroxy Vitamin D3, calcium, phosphorus, total protein, albumin (to account for bound calcium) [1], and serum alkaline phosphatase (a measure of bone loss) [2] were determined at the termination of experiments.

Results: Although the serum calcium and 25-hydroxy Vitamin D3 were significantly higher in groups III and IV compared to groups I and II (P < 0.05), there was no significant difference between the tumor growth rates, final tumor weights (P = 0.9), and the serum PSA levels (P = 0.94) between the four groups.

Conclusions: The results suggest that dietary calcium does not significantly affect the growth of heterotopic LNCaP prostate cancer in nude mice.