Fumes from meat cooking and lung cancer risk in Chinese women

Chinese women are recognized to have a high incidence of lung cancer despit e a low smoking prevalence. Several studies have implicated domestic exposu re to cooking fumes as a possible risk factor, although the exact carcinoge ns have yet to be identified. Heterocyclic amines are known carcinogens, wh ich have been identified in cooked meat, and also in fumes generated during frying or griping of meats. We conducted a case-control study of 303 Chine se women with pathologically confirmed, primary carcinomas of the lung and 765 controls to examine the association between exposure to meat cooking an d lung cancer risk. Data on demographic background, smoking status, and dom estic cooking exposure, including stir-frying of meat, were obtained by in- person interview while in hospital. The response rates among eligible cases and controls were 95.0 and 96.9,%, respectively. The proportion of smokers (current or ex-smokers) among cases and controls was 41.7 and 13.1,%, resp ectively. Adenocarcinomas comprised 31.5% of cancers among smokers and 71.6 % among nonsmokers. When cases were compared with controls, the odds ratio (OR) for lung cancer tall subtypes) among ex-smokers was 4.3 [95% confidenc e interval (CI) 2.7-6.8] and that among current smokers was 5.0 (95% CI, 3. 4-7.3), Among smokers, women who reported that they stir-fried daily in the past had a significantly increased risk of lung cancer (adjusted OR, 2.0; 95% CI, 1.0-3.8) and among these women, risk was enhanced for those who sti r-fried meat daily (OR, 2.7; 95% CI, 1.3-5.5), Women who stir-fried daily b ut cooked meat less often than daily did not show an elevated risk (OR, 1.0 , 95% CI, 0.5-2.4), Risk was further increased among women stir-frying meat daily who reported that their kitchen was fined with oily fumes during coo king (OR, 3.7; 95% CI, 1.8-7.5), These cooking practices on their own did n ot increase risk among nonsmokers in our study population. Our results sugg est that inhalation of carcinogens, such as heterocyclic amines generated d uring frying of meat, may increase the risk of lung cancer among smokers. F urther studies in different settings are warranted to examine this possibil ity, which may also help to explain the higher risk observed among women sm okers compared with men.