Summary of case-control studies of C. pneumoniae and lung cancer risk with blood sampled at or after lung cancer diagnosis and at a comparable time in the controls
| First author, year, location | Number of cases/controls | Case population/selection | Control population/selection | Matching factors | Confounders adjusted for |
|---|---|---|---|---|---|
| Jackson, 2000 (26), USA | 148 cases/148 controls | Men in WA state diagnosed with LC between 5/93 and 7/96, identified through the SEER cancer registry. Population based. | Men without LC identified through random digit dialing. | Age (5-y categories) and gender | Smoking status (current or former), pack-years (<40 or ≥40) and education |
| Koyi, 2001 (25), Sweden | 177 cases/C1 = 68, C2 = 111 | Diagnosed with LC at a single hospital between 2/97 and 2/98. Hospital based. | C1: Consecutive blood donors who were former or current smokers presenting at the same hospital during spring 1998 (exclusions: history of MI, medication for hypertension, or other CV diseases). C2: Participants in a study of current and ex-smokers >70 y old | None | None |
| Kocazeybek, 2003 (27), Turkey | 123 cases/123 controls | Smokers admitted to an Istanbul hospital with a diagnosis of LC between 6/98 and 7/2000. Hospital based. | Healthy hospital staff, relatives of the patients, blood donors, or persons with similar age, sex, and smoking habits and not having any medical treatment for a local or systemic disease and not admitted to the hospital in the previous 2 months | Age (5-y age group), sex, living environment (i.e., province), smoking status (former or current), duration (10-y categories), and quantity of cigarettes smoked (4 categories) | In primary analyses, none. |
Abbreviations: WA, Washington; LC, lung cancer; MI, myocardial infarction; CV, cardiovascular; SEER, Surveillance, Epidemiology, and End Results; C1, control group 1; C2, control group 2.