Table 4.

Histopathologic analysis of tumors in A/J mice receiving NNK with or without nicotinea

Incidence (% of mice)Multiplicity (average per mouse ± SD)
GroupTreatmentAdenomaAdenoma with dysplasiaCarcinomaAdenomaAdenoma with dysplasiaCarcinoma
1 (n = 14)No nicotine/saline7700.07 ± 0.270.07 ± 0.270.0
2 (n = 15)Nicotine (0–46 wks)/saline80150.08 ± 0.280.00.15 ± 0.40
3 (n = 18)No nicotine/NNK8356283.4 ± 2.40.83 ± 0.920.44 ± 0.78
4 (n = 18)Nicotine (0–46 wks)/NNK8961444.4 ± 2.71.0 ± 1.10.67 ± 0.91
5 (n = 19)Nicotine (0–2 wks)/NNK9563284.8 ± 3.51.0 ± 0.940.37 ± 0.68
6 (n = 20)Nicotine (2–46 wks)/NNK8565504.4 ± 2.60.8 ± 0.700.70 ± 0.80
  • aTreatments were as described in Fig. 1 and Table 3. Histologic analysis was not conducted on lungs from 5 mice in groups 1 and 2. Premature deaths occurred in groups 2 to 5 as follows: group 2, one death, week 3, cause of death—unknown, no microscopic analysis of tissues; group 3, one death, week 5, cause of death—unknown and one death at week 29, cause of death—disseminated lymphoma, pulmonary adenomas present; group 4, one death, week 43, cause of death—respiratory distress, adenocarcinoma with multifocal pulmonary adenomas, bronchiolar epithelial hyperplasia, alveolar histiocytosis, and hemorrhage and one death at week 37 after NNK injection. Cause of death—dorsal skin tumor (a large nonmalignant hematoma) pulmonary adenomas present; group 5, one death, week 11, euthanized because of “labored breathing” no microscopic analysis of tissues.