The growth of transplanted tumours in mice after chronic inhalation of fresh cigarette smoke.

The subcutaneous growth of the Lewis lung tumour in C57BL mice chronically exposed to fresh cigarette smoke was increased above that in age-matched control mice. When murine sarcoma virus (Harvey) induced tumour cells were introduced to the lungs of groups of BALB/c mice, only mice chronically exposed to fresh cigarette smoke died with tumour cells in the lungs. Tumour cell growth in mice during short term cigarette smoke exposure was indistinguishable from that in controls.