Table 2. Tumor characteristics in relation to smoking status at the preoperative visit.
| All |
Smoker at the preoperative visita |
|||
|---|---|---|---|---|
| Number and % |
Number and % |
|||
| Yes | No | |||
| n=1065 | n=223 (21%) | n=840 (79%) | P-value | |
| Invasive tumour size | Ptrend=0.19 | |||
| In situ | 39 (3.7%) | 13 (5.8%) | 26 (3.1%) | |
| 1–20 mm | 740 (69.5%) | 155 (69.5%) | 584 (69.5%) | |
| 21–50 mm | 269 (25.3%) | 51 (22.9%) | 217 (25.8%) | |
| 51 or larger | 15 (1.4%) | 4 (1.8%) | 11 (1.3%) | |
| Muscle or skin involvement | 2 (0.2%) | 0 (0.0%) | 2 (0.2%) | |
| ⩾21 or muscle or skin involvement | 286 (26.9%) | 55 (24.7%) | 230 (27.4%) | P=0.42 |
| Missing | 0 | 0 | 0 | |
| No. of involved axillary lymph nodes | Ptrend=0.55 | |||
| 0 | 665 (62.6%) | 146 (65.5%) | 519 (61.9%) | |
| 1–3 | 307 (28.9%) | 57 (25.6%) | 249 (29.7%) | |
| 4+ | 91 (8.6%) | 20 (9.0%) | 70 (8.4%) | |
| Axillary node involvement (yes) | 398 (37.4%) | 77 (34.5%) | 319 (38.1%) | P=0.33 |
| Missing | 2 | 0 | 2 | |
| Histological grade | Ptrend=0.45 | |||
| I | 252 (23.8%) | 66 (29.9%) | 186 (22.2%) | |
| II | 519 (49.0%) | 89 (40.3%) | 430 (51.4%) | |
| III | 288 (27.2%) | 66 (29.9%) | 220 (26.3%) | |
| Histologic grade III (Yes) | 288 (27.2%) | 66 (29.9%) | 220 (26.3%) | P=0.29 |
| Missing | 6 | 2 | 4 | |
| Hormone receptor status | ||||
| ER+ | 899 (87.1%) | 176 (82.2%) | 722 (88.5%) | P=0.02 |
| PgR+ | 728 (70.7%) | 135(63.4%) | 592 (72.7%) | P=0.008 |
| ER+PgR+ | 722 (70.2%) | 132 (62.0%) | 589 (72.4%) | P=0.003 |
| ER+PgR− | 176 (17.1%) | 43 (20.2%) | 133 (16.3%) | P=0.18 |
| ER−PgR− | 125 (12.1%) | 35 (16.4%) | 89 (10.9%) | P=0.03 |
| ER−PgR+ | 6 (0.6%) | 3 (1.4%) | 3 (0.4%) | P=0.11b |
| Missing | 36 | 10 | 26 | |
| HER2 gene amplificationc | 86 (12.5%) | 13 (9.6%) | 72 (13.1%) | P=0.26 |
| Missing | 377 | 87 | 290 | |
Abbreviations: ER=oestrogen receptor; HER2=human epidermal growth factor 2; PgR=progesterone receptor tumours.
a
Smoking status missing for two patients.
b
Fisher's exact test.
c
HER2 was routinely analysed first as of November 2005, and in patients younger than 70 years of age with invasive tumours. The bold numbers indicate statistical significance.