More Evidence of Smoking Multiplying the Risks for Lung Cancer Among Persons Exposed to Asbestos
Evidence continues to grow regarding cigarette smoking significantly increasing the risk of contracting lung cancer amont person with "exposure" to asbestos fibers. The evidence should be important due to continuing increases in lawsuits filed against "asbestos defendants" by persons stricken by non-mesothelioma lung cancer. The suits typically, however, do not name tobacco sellers as defendants, despite the certain connection between smoking and lung cancers.
Some of the latest evidence is a newly published case-control study based on analysis for Health Canada. The study reports on analysis of questionnaires completed during the period 1994-1997. The study is online here in a provisional format, and is titled: Occupational exposure to asbestos and lung cancer in men: evidence from a population-based case-control study in eight Canadian provinces, BMC Cancer 2012, 12:595 doi:10.1186/1471-2407-12-595. Set out below is the conclusion regarding the impact of cigarette smoking:
Stratified analyses of highest attained asbestos exposure across cigarette pack years categories are presented in Table 3. There was an approximate two-fold increase in risk among those with ‘medium’ or ‘high’ occupational exposure to asbestos relative to those with no such exposure in each of the three pack-year categories. This is consistent with a multiplicative relationship between the two factors. Those who had at least 40 pack-years of smoking and were exposed to medium or high asbestos levels had the highest risk of lung cancer; relative to those with no asbestos exposure, and less than 10 cigarette pack-years, their risk nearly 38-fold higher (OR=38.59, 95% CI=10.78-138.08) (Table 4). The calculated values of the S and V indices were 2.10 and 0.99 respectively, supporting the notion that the interaction between asbestos and smoking is multiplicative. (emphasis added)