Table 2.
Incidence and multiplicity of lung tumors in rats treated with DHPN and/or IQ
| Treatment | No. of rats | Adenoma | Carcinoma | Total | |||
|---|---|---|---|---|---|---|---|
| Incidence (%) | Multiplicity (no./rat) | Incidence (%) | Multiplicity (no./rat) | Incidence (%) | Multiplicity (no./rat) | ||
| 0.1% DHPN | 19 | 18 (95)** | 2.84 ± 1.57** | 11 (58)** | 0.79 ± 0.85** | 19 (100)** | 3.63 ± 1.80** |
| 0.1% DHPN/150 p.p.m. IQ | 20 | 20 (100) | 8.30 ± 3.93*** | 19 (95)*** | 3.20 ± 2.24*** | 20 (100) | 11.50 ± 5.04*** |
| 0.1% DHPN/300 p.p.m. IQ | 18 | 18 (100) | 11.72 ± 3.80*** | 18 (100)*** | 7.11 ± 3.01*** | 18 (100) | 18.83 ± 4.58*** |
| 300 p.p.m. IQ | 20 | 5 (25)* | 0.25 ± 0.44 | 0 (0) | 0 | 5 (25)* | 0.25 ± 0.44 |
| Non‐treatment | 10 | 0 (0) | 0 | 0 (0) | 0 | 0 (0) | 0 |
*
P < 0.05;
**
P < 0.01, significantly different from non‐treatment group:
***
P < 0.01, significantly different from DHPN alone. For DHPN‐initiated groups, IQ dose‐dependency was observed in all multiplicity data (P < 0.01).