Table 1.

Growth characteristics of MPA- and progesterone-treated DMBA-induced tumors

Group (wk of treatment)Mean latency period (d)Tumor incidence at 8 wk (%)Final tumor incidence at 10 wk (%)Multiplicity* at 8 wkMultiplicity at 10 wk
No treatment
DMBA control53 ± 111 ± 349 ± 51.0 ± 01.3 ± 0.01
DMBA + MPA (4 wk)37 ± 157 ± 977 ± 3.32.5 ± 0.33.0 ± 0.1
DMBA + MPA (6 wk)47 ± 143 ± 1386 ± 2.92.5 ± 0.13.2 ± 0.2
  • * Number of tumors/tumor-bearing rat.

  • P < 0.05, compared with DMBA controls (unpaired t test).

  • P < 0.05, compared with DMBA controls (χ2 analysis).