Table 2.
Effect of continuous hormonal treatments for 39 weeks on lobulo-alveolar differentiation (LA Diff) and mammary carcinoma (MC) in ovary intact and ovariectomized ACI rats
| Treatment | Intact |
Ovariectomized |
||||
|---|---|---|---|---|---|---|
| Group | LA Diff | MC* | Group | LA Diff | MC* | |
| Untreated control | 1 | No | 0/10 | 6 | No | 0/10 |
| Low E | 2 | Slight | 0/15 | 7 | Slight | 0/15 |
| High E† | 3 | Extensive | 5/7 | 8 | Extensive | 0/8 |
| 30 mg P | 4 | Slight | 0/15 | 9 | No | 0/15 |
| Low E plus 30 mg of P | 5 | Some | 0/15 | 10 | Slight | 0/14 |
| High E plus 30 mg of P | — | ND | ND | 11 | Most Extensive | 11/11 |
| High E plus 30 mg of P plus 30 mg of TP | — | ND | ND | 12 | Most Extensive | 14/14 |
Hormone treatment was initiated at 6 weeks of age and terminated at 45 weeks of age after 39 weeks of treatment. E, estrogen; P, progesterone; TP, testosterone propionate; ND, not done.
*Number of rats with mammary carcinoma/total rats in group.
†At 28 weeks of age (22 weeks of treatment), 30-mg E capsules were exchanged with 3-mg E capsules for the remainder of the experiment.