Table 20.
Meta-analyses for additional lung cancer types (all lung cancer)a
| Lung cancer type | Statisticb | Ever smoking | Current smoking | Ever/current smoking |
|---|---|---|---|---|
| All lung cancerc |
n |
328 |
195 |
342 |
| |
F |
4.22 (4.16-4.28) |
9.29 (9.07-9.52) |
4.25 (4.20-4.31) |
| |
R |
5.50 (5.07-5.96) |
8.43 (7.63-9.31) |
5.48 (5.07-5.93) |
| |
H, PH |
22.84, p < 0.001 |
13.76, p < 0.001 |
22.46, p < 0.001 |
| Squamous cell carcinoma |
n |
74 |
33 |
82 |
| |
F |
10.43 (9.72-11.20) |
12.74 (11.71-13.87) |
9.80 (9.18-10.47) |
| |
R |
11.56 (9.68-13.81) |
16.43 (12.66-21.32) |
11.62 (9.80-13.78) |
| |
H, PH |
4.18, p < 0.001 |
5.70, p < 0.001 |
4.44, p < 0.001 |
| Adenocarcinoma |
n |
87 |
40 |
96 |
| |
F |
3.58 (3.39-3.78) |
4.40 (4.12-4.70) |
3.50 (3.33-3.67) |
| |
R |
2.99 (2.49-3.58) |
4.05 (3.15-5.22) |
3.10 (2.52-3.65) |
| |
H, PH |
9.18, p < 0.001 |
12.28, p < 0.001 |
8.96, p < 0.001 |
| Large cell carcinoma |
n |
26 |
15 |
29 |
| |
F |
6.11 (4.78-7.81) |
8.41 (6.36-11.12) |
5.57 (4.48-6.92) |
| |
R |
5.59 (4.05-7.72) |
8.56 (5.29-13.86) |
5.33 (4.02-7.07) |
| |
H, PH |
1.47, p < 0.1 |
2.13, p < 0.01 |
1.40, p < 0.1 |
| Small cell carcinoma |
n |
54 |
27 |
61 |
| |
F |
9.88 (8.94-10.02) |
15.31 (13.64-17.19) |
9.99 (9.09-10.97) |
| |
R |
10.98 (8.25-14.61) |
18.17 (12.92-25.56) |
11.14 (8.59-14.46) |
| H, PH | 6.08, p < 0.001 | 5.67, p < 0.001 | 5.70, p < 0.001 |
a Within each study, results for the relevant lung cancer type and smoking status are selected in the following preference order, within each sex, for:
smoking product – any, cigarettes (ignoring other products), cigarettes only;
cigarette type – any, manufactured (with or without handrolled), manufactured only;
unexposed group – never any product, never cigarettes, other;
follow-up period – longest available;
race – all or nearest available, otherwise by race;
overlapping studies – principal, subsidiary;
age – whole study, widest available age group;
Results are then selected for:
sex – single sex results, combined sex results;
adjustment for potential confounders – most available.
b n = number of estimates combined, F = fixed-effect meta-analysis RR (95% CI), R = random-effects meta-analysis RR (95% CI), H = heterogeneity chisquared per degree of freedom, PH = probability value for heterogeneity expressed as p < 0.001, p < 0.05, p < 0.1 or NS (p ≥ 0.1), PB = probability value for between levels (see Methods) similarly expressed.
c All or nearest available, must include at least squamous cell carcinoma and adenocarcinoma.