The anti-neoplastic effect of trichinellosis in a syngeneic murine model.

C57BL/6 male mice with chronic trichinellosis, and age-matched uninfected control mice, were inoculated with B16 melanoma cells. Tumour development was inhibited in the infected animals. In the infected tumour-bearing mice, the tumor induction intervals were longer and the tumour size was subsequently smaller than in the control mice. Moreover, when the number of tumour cells in the inoculum was less than that required to produce 100% tumour incidence in the uninfected mice (less than 1 x 10(4) cells), significantly more of the mice with an infection of 2 months duration remained tumour-free. These results were significant at the P less than 0.05 level.