Table 1.
Characteristics of squamous cell carcinoma cases and controls.
| Variable | Case | Control | p-Value |
|---|---|---|---|
| n | 242 | 336 | |
| Age at lung cancer diagnosis (years, mean ± SD) | 60.3 ± 10.4 | — | |
| Survival after diagnosis [years, median (Q1–Q3)] | 0.6 (0.1–2.3) | — | |
| Age at death (years, mean ± SD) | 62.6 ± 10.6 | 69.2 ± 12.5 | 2.8 × 10–10a |
| Sex (male percent) | 100 | 100 | |
| Ethnicity (non-Hispanic white %) | 100 | 100 | |
| WLM [kWLMs,b median (Q1–Q3)] | 1.0 (0.5–2.1) | 0.8 (0.4–1.5) | 0.001c |
| < 0.895 (%) | 41.1 | 54.0 | 0.055d |
| ≥ 0.895 (%) | 48.6 | 45.4 | |
| Missing (%) | 10.4 | 0.6 | |
| Mid-induction latency [years, median (Q1–Q3)]e | 19 (12.0–26.5) | ||
| WLM, working level month. aStudent’s t-test. bTwenty-seven miners had missing cumulative WLM estimates. WLM, a time-integrated measure, was calculated as the product of time in working months (1 month = 170 hr) and working levels to estimate the cumulative exposure to radon daughter radiation for each miner. cWilcoxon rank-sum test. dChi-square test for differences between cases and controls. The missing group was not included in this test. eSquamous cell carcinoma cases (n = 162) with complete information for latency and genotypes. Mid-induction latency defined as time from midpoint of the period of substantial exposure (an annual accumulative dose of ≥ 50.6 mSv) to squamous cell carcinoma diagnosis (Archer et al. 2004). | |||