ABSTRACT
Previous studies suggested that smoking and passive smoking could increase the risk of breast cancer, but the results were inconsistent, especially for Chinese females. Thus, we systematically searched cohort and case-control studies investigating the associations of active and passive smoking with breast cancer risk among Chinese females in four English databases (PubMed, Embase, ScienceDirect, and Wiley) and three Chinese databases (CNKI, WanFang, and VIP). Fifty-one articles (3 cohort studies and 48 case-control studies) covering 17 provinces of China were finally included in this systematic review. Among Chinese females, there was significant association between passive smoking and this risk of breast cancer [odds ratio (OR): 1.62; 95% confidence interval (CI): 1.39-1.85; I2 = 75.8%, P < 0.001; n = 26] but no significant association between active smoking and the risk of breast cancer (OR: 1.04; 95% CI: 0.89-1.20; I2 = 13.9%, P = 0.248; n = 31). The OR of exposure to husband's smoking and to smoke in the workplace was 1.27 (95% CI: 1.07-1.50) and 1.66 (95% CI: 1.07-2.59), respectively. The OR of light and heavy passive smoking was 1.11 and 1.41, respectively, for women exposed to their husband's smoke (< 20 and ≥ 20 cigarettes per day), and 1.07 and 1.87, respectively, for those exposed to smoke in the workplace (< 300 and ≥ 300 min of exposure per day). These results imply that passive smoking is associated with an increased risk of breast cancer, and the risk seems to increase as the level of passive exposure to smoke increases among Chinese females. Women with passive exposure to smoke in the workplace have a higher risk of breast cancer than those exposed to their husband's smoking.
Subject(s)
Female , Humans , Breast Neoplasms , China , Cohort Studies , Occupational Exposure , Odds Ratio , Risk Factors , Smoking , Tobacco Smoke PollutionABSTRACT
<p><b>OBJECTIVE</b>To explore the secular trend in incidence and mortality rate of gastric cancer in Tianjin and to provide evidence and reference for making prevention and control strategy for gastric cancer.</p><p><b>METHODS</b>Data derived from Tianjin cancer registry system were analyzed by descriptive epidemiological method and Joinpoint model. A total of 17990 gastric cancer cases reported in Tianjin from 1981 to 2002, including 12755 males and 5235 females were studied.</p><p><b>RESULTS</b>The annual percent change (APC) of crude incidence rate for males and females was -0.92% (Z = -3.85, P = 0.001) and -0.79% (Z = -2.67, P = 0.015), while the APC of standard incidence rate was -3.55% (Z = -13.52, P = 0.000) and -3.47% (Z = -12.85, P = 0.000). There was a descending trend of incidence rate in males and females above 45-years-old, however, in male under 45 years it showed an increased trend and in females it kept stable. The APC of crude mortality rate was -1.66% ( Z = -5.79, P = 0.000) for males and -1.84% (Z = -6.02,P = 0.000) for females, while the APC of standard mortality rate was -4.60% ( Z = -15.79, P = 0.000) for females and -5.36% ( Z = -8.28, P = 0.000) for males during 1989-2002. Mortality and incidence ratio also indicated a downward trend.</p><p><b>CONCLUSION</b>Despite its declining trend in Tianjin, gastric cancer still remains an important public health problem in facing of the aging society and many risk factors.</p>