Objective: The association between previous lung diseases (PLD) and lung cancer risk has not been studied extensively. We conducted a registry-based case-control study to examine the relation between previous lung diseases and lung cancer among women in Missouri.
Methods: Incident cases (n = 676) were identified through the Missouri Cancer Registry for the period 1 January 1993 to 31 January 1994. Controls (n = 700) were selected through drivers' license files and Medicare files.
Results: Whether analyzing all respondents or in-person interviews only, elevated effect estimates were noted for several types of PLD. Elevated relative risk estimates were shown for chronic bronchitis (odds ratio [OR] = 1.7; 95% confidence interval [CI] = 1.2-2.3), emphysema (OR = 2.7; 95% CI = 1.8-4.2), pneumonia (OR = 1.6; 95% CI = 1.2-2.0), and for all PLDs combined (OR = 1.5; 95% CI = 1.2-1.9). Analysis of only direct interviews did not show a substantial or consistent pattern of change in relative risk estimates. Because PLDs identified close to the time of cancer diagnosis could conceivably be misdiagnosed, resulting from early lung cancer symptoms, we evaluated the effects on risk estimates of a "latency exclusion" of up to three years. When these exclusions were taken into account, ORs remained statistically significantly elevated only for emphysema.
Conclusion: When earlier epidemiologic findings and underlying biological and genetic factors are taken into account, an association between PLD and lung cancer is plausible.