Table 1.
Mammary tumor totals in rapid and slow acetylator congenic rats administered MNU or DMBA
| Treatment Protocol | Acetylator phenotype | Rats treated and necropsied | Rats with tumors (%)a | Total tumors | Total tumors per ratb,c | Total tumors per rat in tumor- bearing ratsc |
|---|---|---|---|---|---|---|
| MNU 3 weeks | Rapid | 42 | 28 (66.7%) | 42 | 1.00 ± 0.17 | 1.50 ± 0.20 |
| MNU 3 weeks | Slow | 34 | 18 (52.9%) | 23 | 0.67 ± 0.12 | 1.28 ± 0.11 |
| MNU 8 weeks | Rapid | 24 | 10 (41.6%)* | 12 | 0.50 ± 0.14* | 1.20 ± 0.20 |
| MNU 8 weeks | Slow | 33 | 5 (15.2%)* | 8 | 0.24 ± 0.12* | 1.60 ± 0.24 |
| DMBA 8 weeks | Rapid | 25 | 19 (76.0%)* | 30 | 1.20 ± 0.16** | 1.58 ± 0.12 |
| DMBA 8 weeks | Slow | 30 | 13 (43.3%)* | 17 | 0.57 ± 0.14** | 1.31 ± 0.17 |
aTumor incidence
bTumor multiplicity
cMean ± SEM. Total mammary tumors differed significantly *(p < 0.05) ** (p < 0.01) between rapid and slow acetylator rats