Table 1.

(A) Breast tumor frequency in experimental and control mice
GroupTotal no. miceNo. mice with single tumorNo. mice with two tumorsNo. mice with three tumorsTotal no. tumors
Experiment 1
    Gentamicin1342111
    Controls124208
Experiment 2
    Metronidazole/ciprofloxacin1072011
    Controls126006
(B) Statistical comparison of breast tumor occurrence in treated and control mice
HR (95% CI)P (likelihood ratio test)
Gentamicin vs control1.39 (0.56-3.47)0.481
Metronidazole/ciprofloxacin vs control3.11 (1.13-8.53)0.028