Effects of amputation and Corynebacterium parvum on tumour metastases in mice.

The effects of operation (lower-limb amputation) on the growth of the Lewis lung tumour and its metastases were studied. The role of C. parvum in counteracting these effects was investigated. Anaesthesia alone or with amputation did not affect primary tumour growth. C. parvum depressed this growth. Anaesthesia did not affect the number of pulmonary metastases, but amputation caused a significant increase. C. parvum inhibited metastases and completely counteracted the effects of operation on them. Large doses of cortisone acetate significantly increased metastases but small doses had no effect. Experiments with adrenalectomized mice suggested the effects of operation were due to non-specific stress.