Table 2.
Smoking history among three cohorts of US breast cancer survivors (n = 9975)*
| Smoking history | WHEL No. (%) | LACE No. (%) | NHS No. (%) | All No. (%) |
|---|---|---|---|---|
| Smoking status | ||||
| Never | 1643 (53.8) | 1195 (52.9) | 1974 (42.4) | 4812 (48.2) |
| Current | 138 (4.5) | 173 (7.7) | 399 (8.6) | 710 (7.1) |
| Former | 1276 (41.7) | 891 (39.4) | 2272 (48.8) | 4439 (44.5) |
| Unspecified | 0 | 0 | 14 (0.3) | 14 (0.1) |
| Cigarettes/day | ||||
| Current smokers | ||||
| <5 | 32 (23.2) | 22 (12.7) | 38 (9.5) | 92 (13.0) |
| 5–14 | 62 (44.9) | 83 (48.0) | 125 (31.3) | 270 (38.0) |
| 15–24 | 32 (23.2) | 55 (31.8) | 155 (38.9) | 242 (34.1) |
| ≥25 | 12 (8.7) | 9 (5.2) | 60 (15.0) | 81 (11.4) |
| Unspecified | 0 | 4 (2.3) | 21 (5.3) | 25 (3.5) |
| Former smokers | ||||
| <5 | 350 (27.5) | 155 (17.4) | 342 (15.1) | 847 (19.1) |
| 5–14 | 388 (30.4) | 283 (31.8) | 736 (32.4) | 1407 (31.7) |
| 15–24 | 340 (26.7) | 293 (32.9) | 743 (32.7) | 1376 (31.0) |
| ≥25 | 189 (14.8) | 132 (14.8) | 376 (16.6) | 697 (15.7) |
| Unspecified | 9 (0.7) | 28 (3.1) | 75 (2.4) | 112 (2.5) |
| Years of smoking | ||||
| Current smokers | ||||
| <10 | 13 (9.4) | 4 (2.3) | 3 (0.8) | 20 (2.8) |
| 10–19 | 24 (17.4) | 11 (6.4) | 4 (1.0) | 39 (5.5) |
| 20–29 | 46 (33.3) | 38 (22.0) | 8 (2.0) | 92 (13.0) |
| ≥30 | 55 (39.9) | 118 (68.2) | 377 (94.5) | 550 (77.5) |
| Unspecified | 0 | 2 (1.2) | 7 (1.8) | 9 (1.3) |
| Former smokers | ||||
| <10 | 572 (44.8) | 208 (23.3) | 413 (18.2) | 1193 (26.9) |
| 10–19 | 335 (26.3) | 234 (26.3) | 525 (23.1) | 1094 (24.7) |
| 20–29 | 237 (18.6) | 207 (23.2) | 486 (21.4) | 930 (21.0) |
| ≥30 | 125 (9.8) | 234 (25.1) | 807 (35.5) | 1156 (26.0) |
| Unspecified | 7 (0.6) | 18 (2.0) | 41 (1.8) | 66 (1.5) |
| Pack-years | ||||
| 0 | 1644 (53.8) | 1197 (53.0) | 1974 (42.4) | 4815 (48.3) |
| 0.1–10 | 775 (25.4) | 467 (20.7) | 803 (17.2) | 2045 (20.5) |
| 10.1–19.9 | 245 (8.0) | 167 (7.4) | 457 (9.8) | 869 (8.7) |
| 20.0–34.9 | 199 (6.5) | 201 (8.9) | 545 (11.7) | 945 (9.5) |
| ≥35 | 179 (5.9) | 188 (8.3) | 796 (17.1) | 1163 (11.7) |
| Unspecified | 15 (0.5) | 39 (1.7) | 84 (1.8) | 138 (1.4) |
* LACE = Life After Cancer Study; NHS = Nurses Health Study; WHEL = Women’s Healthy Eating and Living Study;