Table 2.
Demographic data of Massachusetts lung cancer case-control study
| Variables | Controls | Cases | P value |
|---|---|---|---|
| N | 1555 | 2538 | |
| Age (mean ± SD) | 58.7(12.4) | 65.2(10.7) | <0.0001a |
| Sex (male, %) | 44.2 | 51.1 | 0.0001b |
| Ethnicity (%) | 0.012 b | ||
| White | 97.7 | 96.2 | |
| Others | 2.3 | 3.8 | |
| Smoking status (%) | <0.0001b | ||
| Never | 35.2 | 8.9 | |
| Ex smoker | 45.7 | 51.8 | |
| Current smoker | 19.2 | 39.2 | |
| Pack-years for ever smokers (median, range) | 20.0 (0.1-218) | 51.0 (0.1-231) | <0.0001c |
| Tumor stage (%) | |||
| I and II | 43.5 | ||
| III and IV | 56.5 | ||
| Histology (%) | |||
| Adenocarcinoma | 41.4 | ||
| Squamous cell carcinoma | 20.0 | ||
| Others d | 38.6 | ||
| Rs61768479 genotype (%) | 0.3646 b | ||
| Wild type (CC) | 87.5 | 88.4 | |
| Heterozygous (CG) | 12.1 | 11.0 | |
| Homozygous (GG) | 0.4 | 0.6 |
a
Two-sided two-sample ttest between cases and controls.
b
χ2 test for differences between cases and controls.
c
Two-sided Wilcoxon rank sum test between cases and controls.
d
Others included large cell lung cancer, poorly differentiated and other non-small cell lung cancer.