Introduction
Methods
Smoking at diagnosis and survival: new findings
Study population
Data collection
Statistical analysis
Systematic review and meta-analysis of published findings
Results
Smoking and survival in the cohort
Smoking status at time of diagnosis | ||||
---|---|---|---|---|
Current (n = 1,079) | Former (n = 1,303) | Never (n = 3,510) | Total (n = 5,892) | |
Characteristics of women | ||||
Age (years), mean (SD) | 52.8 (11.5) | 56.1 (11.3) | 59.3 (13.1) | 57.4 (12.7) |
Body mass indexb (kg/m2), mean (SD) | 24.0 (4.6) | 25.5 (5.0) | 25.1 (4.7) | 25.0 (4.8) |
Age (years) at menarcheb, mean (SD) | 12.8 (1.8) | 12.8 (1.7) | 12.9 (1.6) | 12.9 (1.7) |
Parityb, mean (SD) | 1.9 (1.8) | 1.9 (1.8) | 2.3 (2.2) | 2.1 (2.1) |
Postmenopausal womenb (%) | 60.5 | 67.6 | 73.6 | 69.8 |
Age (years) at menopauseb, mean (SD) | 45.4 (6.9) | 46.3 (6.8) | 47.1 (6.4) | 46.7 (6.6) |
Hormone replacement therapy current useb (%) | 17.1 | 17.2 | 17.5 | 17.3 |
Family history of breast cancera, b (%) | 23.2 | 24.5 | 25.6 | 24.9 |
Diabetesb (%) | 1.9 | 1.9 | 2.6 | 2.3 |
Current alcohol intakeb (%) | 39.5 | 47.3 | 27.3 | 34.2 |
Characteristics of the disease and treatment | ||||
Tumor size (mm)b, mean (SD) | 22.9 (17.7) | 22.7 (17.5) | 23.3 (18.3) | 23.1 (18.0) |
Number of axillary nodes examinedb, c, mean (SD) | 12.4 (7.8) | 11.1 (8.2) | 11.2 (7.7) | 11.4 (7.9) |
Positive estrogen receptors (%) | 73.3 | 77.7 | 73.4 | 74.1 |
Positive progesterone receptors (%) | 56.1 | 56.9 | 52.2 | 53.6 |
Well differentiated histological gradeb (%) | 24.5 | 27.8 | 26.0 | 26.1 |
Regional involvement (%) | 39.4 | 36.4 | 36.1 | 36.8 |
Distant metastasis at diagnosis (%) | 3.2 | 2.5 | 3.2 | 3.0 |
Breast-conserving surgeryd (%) | 68.3 | 72.1 | 67.4 | 68.6 |
Axillary surgeryd (%) | 89.4 | 90.9 | 85.0 | 87.1 |
Neoadjuvant therapyd (%) | 5.4 | 6.7 | 6.4 | 6.3 |
Adjuvant radiotherapyb, d (%) | 75.9 | 79.8 | 71.4 | 74.1 |
Adjuvant chemotherapyb, d (%) | 49.0 | 48.6 | 41.4 | 44.4 |
Adjuvant endocrine therapyb, d (%) | 60.8 | 65.2 | 64.7 | 64.1 |
Smoking status | Breast cancer-specific mortality | ||||
---|---|---|---|---|---|
Number of | Crude HR (95% CI) | Agea-adjusted HR (95% CI) | AdjustedbHR (95% CI) | ||
Women | Deaths | ||||
Neverc | 3,510 | 583 | 1.00 | 1.00 | 1.00 |
Former | 1,303 | 185 | 0.94 (0.79 to 1.11) | 0.99 (0.84 to 1.17) | 1.04 (0.88 to 1.24) |
Currentd | 1,079 | 185 | 0.99 (0.84 to 1.16) | 0.99 (0.83 to 1.17) | 1.15 (0.97 to 1.37) |
≤15 pack years | 232 | 40 | 0.82 (0.60 to 1.13) | 0.73 (0.53 to 1.01) | 0.92 (0.66 to 1.28) |
>15 to ≤30 pack years | 278 | 54 | 1.06 (0.80 to 1.40) | 1.05 (0.79 to 1.39) | 1.23 (0.92 to 1.64) |
>30 pack years | 273 | 58 | 1.20 (0.91 to 1.57) | 1.35 (1.03 to 1.78) | 1.52 (1.15 to 2.00) |
P-value, test for trende | 0.08 | 0.004 | 0.002 | ||
≤10 cigarettes/day | 287 | 36 | 0.75 (0.54 to 1.05) | 0.73 (0.52 to 1.02) | 0.97 (0.69 to 1.37) |
>10 to ≤20 cigarettes/day | 395 | 75 | 1.05 (0.83 to 1.34) | 1.06 (0.83 to 1.35) | 1.13 (0.88 to 1.45) |
>20 cigarettes/day | 337 | 70 | 1.17 (0.91 to 1.50) | 1.19 (0.92 to 1.53) | 1.32 (1.02 to 1.70) |
P-value, test for trende | 0.06 | 0.04 | 0.03 | ||
≤20 years | 191 | 44 | 1.06 (0.78 to 1.44) | 0.87 (0.63 to 1.19) | 1.05 (0.76 to 1.45) |
21 to 30 years | 258 | 49 | 0.93 (0.69 to 1.24) | 0.92 (0.68 to 1.24) | 1.06 (0.78 to 1.44) |
>30 years | 340 | 61 | 1.11 (0.85 to 1.45) | 1.30 (1.00 to 1.70) | 1.56 (1.19 to 2.05) |
P-value, test for trende | 0.67 | 0.07 | 0.004 |
Smoking status | All-cause mortality | ||||
---|---|---|---|---|---|
Number of | Crude HR (95% CI) | Agea-adjusted HR (95% CI) | AdjustedbHR (95% CI) | ||
Women | Deaths | ||||
Neverc | 3,510 | 859 | 1.00 | 1.00 | 1.00 |
Former | 1,303 | 267 | 0.93 (0.81 to 1.06) | 1.10 (0.95 to 1.26) | 1.17 (1.01 to 1.34) |
Currentd | 1,079 | 282 | 1.00 (0.87 to 1.14) | 1.21 (1.05 to 1.39) | 1.38 (1.20 to 1.60) |
≤15 pack years | 232 | 52 | 0.67 (0.51 to 0.89) | 0.77 (0.58 to 1.02) | 0.89 (0.67 to 1.19) |
>15 to ≤30 pack years | 278 | 88 | 1.13 (0.91 to 1.41) | 1.37 (1.09 to 1.71) | 1.62 (1.29 to 2.03) |
>30 pack years | 273 | 93 | 1.30 (1.05 to 1.61) | 1.62 (1.30 to 2.01) | 1.83 (1.47 to 2.29) |
P-value, test for trende | 0.0003 | < 0.0001 | < 0.0001 | ||
≤10 cigarettes/day | 287 | 64 | 0.89 (0.69 to 1.15) | 1.01 (0.79 to 1.31) | 1.23 (0.95 to 1.60) |
>10 to ≤20 cigarettes/day | 395 | 114 | 1.04 (0.86 to 1.27) | 1.24 (1.02 to 1.51) | 1.36 (1.11 to 1.67) |
>20 cigarettes/day | 337 | 97 | 1.08 (0.87 to 1.33) | 1.41 (1.14 to 1.75) | 1.56 (1.26 to 1.94) |
P-value, test for trende | 0.30 | 0.001 | 0.0001 | ||
≤20 years | 191 | 54 | 0.80 (0.61 to 1.06) | 0.88 (0.66 to 1.17) | 1.00 (0.75 to 1.34) |
21 to 30 years | 258 | 66 | 0.81 (0.63 to 1.04) | 1.06 (0.82 to 1.38) | 1.24 (0.95 to 1.61) |
>30 years | 340 | 115 | 1.45 (1.20 to 1.77) | 1.65 (1.36 to 2.01) | 1.95 (1.59 to 2.38) |
P-value, test for trende | 0.002 | < 0.0001 | < 0.0001 |
Systematic review and meta-analysis of published findings
Country | Years of follow-up | Stage | No. participants | Breast cancer deaths | |||
---|---|---|---|---|---|---|---|
Study | Current | Never | Current | Never | |||
smokers | smokers | smokers | smokers | ||||
Tominaga et al. [15] | Japan | 1986 to 1995 | I to IV | 68 | 325 | - | - |
Manjer et al. [12] | Sweden | 1977 to 1996 | 0 to IV | 216 | 491 | 48 | 81 |
Fentiman et al. [11] | UK | 1984 to 2004 | I to II | 40 | 67 | - | - |
Sagiv et al. [16] | USA | 1996 to 2002 | Invasive | 252 | 568 | 28 | 52 |
Holmes et al. [9] | USA | 1978 to 2002 | I to III | 1,018 | 2,112 | 216 | 357 |
Dal Maso et al. [8] | Italy | 1991 to 2006 | I to IV | 290 | 934 | 80 | 248 |
Hellmann et al. [6] | Denmark | 1976 to 2007 | Loc/reg/met | 212 | 120 | 96 | 48 |
Braithwaite et al. [5] | USA | 1997 to 2012 | I to III | 173 | 1194 | 25 | 111 |
Warren et al. [4] | USA | 1982 to 2010 | Loc/reg/met | 143 | 480 | - | - |
Bérubé et al. | Canada | 1987 to 2008 | Loc/reg/met | 1,079 | 3,510 | 185 | 583 |