The carcinogenic activity of seven metallic alloys was studied by
implanting solid rods of each alloy in the gluteal muscles of
Sprague-Dawley rats which were killed after twenty-four months. When the
number of tumors in these rats was compared with the numbers in rats not
operated on, in rats which had a sham operation, and in rats implanted with
Silastic rods, no statistically significant differences in the incidences
of the tumors in the several groups were found.