Abstract
B124
Background: Shanxi Province in north central China has among the highest esophageal cancer rates in the world. Although smoking is an important risk factor for esophageal cancer in the Western world, it explains little of the risk in China where over half of all the cases in the world occur. Other sources of exposure to polycyclic aromatic hydrocarbons (PAH), such as cooking and heating practices, might be involved in upper gastrointestinal (UGI) cancers in China. >Methods: 600 esophageal squamous cell carcinoma (ESCC) cases, 600 gastric cardia cancer (GCC) cases, and 313 gastric noncardia cancer (GNCC) cases from the Shanxi Cancer Hospital and 1500 age- and gender-matched neighborhood controls were recruited for this study. A standardized questionnaire obtained demographic characteristics and exposures to potential sources of PAHs, including tobacco, cooking, and heating practices. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) stratified by gender and cancer site and adjusted for matching factors and potential confounders. >Results: 85% of males reported tobacco use, but only 10% of females smoked. In males, ever smoking was not significantly associated with ESCC, GCC, or GNCC. Total pack-years equivalents was associated with ESCC risk (high/low quantile OR=1.59, p-trend=0.004) but not with GCC or GNCC. Indoor (vs outdoor) location of the kitchen, absence (vs presence) of a stove pipe, and coal/wood (vs gas) cooking fuel did not affect risk; smokiness of the house when cooking, if anything, suggested reduced risk for greater smokiness. Use of coal/wood products (vs gas) for home heating was also not associated with risk. As with cooking, ORs for more smokiness in the house when heating were consistently below 1.0, although none was significant. >Conclusion: Tobacco smoking was only modestly associated with UGI cancer risk. There was no evidence for increased risk from cooking and heating practices associated with increased PAH exposure. New methods of accurately quantitating PAH exposure are needed better define risk in UGI and other cancers.
Sixth AACR International Conference on Frontiers in Cancer Prevention Research-- Dec 5-8, 2007; Philadelphia, PA