Table 1.

Effect of TNF status on mammary tumor development, lung metastasis, and mouse weight

Group
TNF−/− 2ATNF+/− 2ATNF+/− 2BTNF+/+ 2B
N30292727
Tumor incidence (mice with tumors visible at sacrifice, %)10.0a20.7a,b22.2a,b44.4b
No. of tumors visible at sacrifice*381118
Visible tumors per mouse0.10 ± 0.06a0.28 ± 0.11a,b0.41 ± 0.18a,b0.67 ± 0.17b
Microscopic hyperplasias/MG1–5,, (0.2–0.5 mm diameter)95.9 ± 13.5a,c85.6 ± 12.8a190.1 ± 29.7b,c150.1 ± 25.5a,c
Microscopic hyperplasias/MG1–5, (0.5–1.0 mm diameter)1.17 ± 0.33a1.28 ± 0.39a1.04 ± 0.38a1.30 ± 0.36a
Microscopic hyperplasias/MG1–5, (>1.0 mm diameter)0.33 ± 0.27a0.66 ± 0.19a0.33 ± 0.12a0.22 ± 0.08a
Lung metastases, #/N (%)§3/28 (10.7%)a2/25 (8.0%)a4/23 (17.4%)a4/27 (14.8%)a
Body weight (g)25.3 ± 0.6a27.0 ± 0.6a,b27.1 ± 0.7a,b28.2 ± 0.7b
Spleen weight (mg/100 g body weight; N)
    All mice479 ± 71 (30)a313 ± 12 (29)a453 ± 55 (26)a426 ± 50 (26)a
    Non–tumor-bearing mice434 ± 55 (27)a,1308 ± 12 (23)a,1387 ± 47 (21)a,1317 ± 20 (15)a,1
    Tumor-bearing mice883 ± 524 (3)a,1330 ± 37 (6)a,1728 ± 169 (5)a,2573 ± 100 (11)a,2
  • *Total visible tumors per group.

  • Microscopic hyperplasias/lesions were counted in mammary glands (MG) 1 to 5 on one side of each mouse. Numbers presented are per mouse.

  • Mean ± SE. Means or percentages in a row without a common superscript letter, or in a column without a common superscript number, are statistically different.

  • §Metastases were found in both visible tumor-bearing (TB) and non tumor-bearing (NTB) mice as follows: TNF−/− 2A, TB 1, NTB 2; TNF+/− 2A, TB 1, NTB 1; TNF+/− 2B, TB 2, NTB 2; TNF+/+ 2B, TB 2, NTB 2.