Table 3.
Relative risks (95% CI) for former smoking for 4 main histologic types of lung cancer, comparing former to never-smokers, Nurses’ Health Study, 1976-2002*
| Years since quitting |
|||||
|---|---|---|---|---|---|
| 1 to < 5 | 5 to < 10 | 10 to < 15 | 15 to < 20 | 20+ | |
| Squamous Cell Carcinoma | |||||
| Cases | 28 | 26 | 13 | 8 | 11 |
| RR | 9.86 (3.87, 25.0) | 8.42 (3.29, 21.6) | 4.39 (1.58, 12.19) | 2.74 (0.89, 8.40) | 0.87 (0.30, 2.53) |
| Small Cell Carcinoma | |||||
| Cases | 24 | 24 | 6 | 4 | 2 |
| RR | 36.9 (7.95, 171.2) | 33.9 (7.29, 157.2) | 8.42 (1.56, 45.6) | 5.69 (0.95, 34.1) | 0.66 (0.09, 5.13) |
| Adenocarcinoma | |||||
| Cases | 70 | 53 | 47 | 28 | 60 |
| RR | 3.10 (2.10, 4.58) | 2.28 (1.57, 3.44) | 2.15 (1.40, 3.28) | 1.37 (0.84, 2.24) | 0.76 (0.50, 1.14) |
| Large Cell Carcinoma | |||||
| Cases | 6 | 13 | 6 | 4 | 4 |
| RR | 2.30 (0.71, 7.42) | 5.08 (1.84, 13.99) | 2.50 (0.76, 8.16) | 1.69 (0.45, 6.37) | 0.48 (0.13, 1.79) |
| All Histologic Types | |||||
| Cases | 128 | 116 | 72 | 44 | 77 |
| RR | 4.18 (3.05, 5.73) | 3.64 (2.65, 5.01) | 2.37 (1.67, 3.37) | 1.53 (1.02, 2.28) | 0.67 (0.47, 0.96) |
*
Separate regression models for each histologic type, adjusted for age, cigarettes smoked per day before quitting, and follow-up period. Reference category consists of never-smokers. See Table 2.