Tobacco Documents Online

Wu-Williams, A.H., Dai, X.D., Blot, W., Xu, Z.Y., Sun, X.W., Xiao, H.P., Stone, B.J., Yu, S.F., Feng, Y.P., Ershow, A.G., Sun, J., Fraumeni, J.F., and Henderson, B.E., "Lung Cancer Among Women in North-East China," British Journal of Cancer 62: 982'.-987, 1990. United States and Chinese researchers collaborated on this large case-control study, conducted in two industrialized cities whose lung cancer rates are among the highest in China. Data were collected by personal interview with 964 cases and 959 controls (the authors do not indicate whether any surrogate respondents were used). Histological information was available for only 42% of the cases. A number of potential confounders, including diet, history of lung disease, and use of traditional heating devices, were examined. Although the authors reported no statistically significant case-control differences regarding several indices of ETS exposure, they nevertheless wrote: "Despite the large size of our study, we were unable to clarify the magnitude of risks due to passive smoking, recognised as a cause of lung cancer around the world." An OR of 0.7 (95% CI 0.6-0.9) was reported for spousal smoking among nonsmoking individuals (205 cases, 331 controls); this OR is statistically significantly negative. For nonsmokers reporting ETS exposure in the workplace, the authors reported an~ odds ratio of 1.1 (95% CI 0.9- 1.6). Although the reported OR was not statistically significant, the authors characterized it as "a small excess risk." ORs for mother or father smoking,were presented. However, it appears that these analyses represented adult rather than childhood exposure. Nonetheless, neither was statistically significant. Statistically significantly elevated ORs were reported for the use of indigenous heating devices. For instance, use of "kang,'"' brick beds heated directly by a stove beneath them, for more than 21 years was associated with an OR of 1.5 (95% CI 1.1-2.0). Cooking practices were also associated with statistically significant elevated relative risks. For instance, deep frying more than two times per month had a reported OR of 2.1 (95% CI 1.5-2.8), and experiencing frequent eye irritation while cooking had an OR of 1.8 (95% CI 1.3- 2.6)~. ORs for certain medical history variables were also statistically elevated'. A history of tuberculosis in a household member had an OR of 1.6 (95% CI 1.2-2.1), and a history of pneumonia in the home had an OR of 2.3 ~ 0 W ~ ~ W a 0 Ul

(reportedly statistically significant, but no CI was given) . The authors claim that their data suggested there was no effect of diet on lung cancer risk. This conclusion is not consistent with~ data presented in other studies, which suggest that certain dietary variables may be related to lung cancer risk.