Evaluation of breast cancer risk associated with tea consumption by menopausal and estrogen receptor status among Chinese women in Hong Kong.

PURPOSE: Experimental studies implicate tea and tea polyphenols may be preventive against breast cancer, but evidence from epidemiological studies has been inconsistent. We conducted a hospital-based case-control study to evaluate the role of tea especially green tea in breast cancer etiology. METHODS: We consecutively recruited 756 incident breast cancer cases and 789 hospital controls who had completed information on tea consumption. We calculated odds ratios (ORs) for tea consumption using unconditional multivariable logistic regression. We further conducted stratified analyses to assess whether the effect of tea consumption varied by menopausal status and estrogen receptor (ER). RESULTS: Overall, 439 (58.1%) breast cancer cases and 434 (55.0%) controls reported habits of regular tea drinking, showing an adjusted OR of 1.01 (95%CI: 0.78-1.31) and 1.20 (95%CI: 0.80-1.78) for any tea and green tea drinking, respectively. Regular tea drinking was significantly associated with a lower risk for breast cancer in pre-menopausal women (OR=0.62, 95%CI: 0.40-0.97) but an increased risk in post-menopausal women (OR=1.40, 95%CI: 1.00-1.96). The positive association among postmenopausal women was strongest among ER-negative green tea drinkers (OR=2.99, 95% CI: 1.26-7.11). CONCLUSIONS: Tea or green tea drinking was not associated with overall breast cancer risk, which may be masked by the differential effect in pre- and post-menopausal women.

Joint effects of environmental exposures and familial susceptibility to lung cancer in Chinese never smoking men and women.

OBJECTIVES: Previous epidemiological studies had limited power to investigate the joint effects of individual environmental risk factors and familial susceptibility to lung cancer. This study aimed to address this shortcoming. METHODS: We recruited 345 never smoking lung cancer cases and 828 community referents. We developed a collective environmental exposure index by assigning a value of 1 to subjects at high risks regarding environmental risk factors and 0 otherwise, and then summed over using weights equivalent to the excess odds ratio. Potential additive and multiplicative interactions between environmental exposure index and family cancer history were examined. RESULTS: Compared with "low environmental exposure and without family cancer history", the odds ratio was 6.80 (95% confidence interval = 3.31-13.98) for males who had high environmental exposures but without family cancer history, whereas it increased to 30.61 (95% confidence interval = 9.38-99.87) if they also had a positive family history. The corresponding associations became weaker in never smoking females. No multiplicative interaction was observed for both genders and an additive interaction was restricted among males. CONCLUSIONS: This study developed a novel environmental exposure index that offers sufficient interest deserving further studies on the interactions between environmental exposures and familial susceptibility to lung cancer risk.

Lead powder use for skin care and elevated blood lead level among children in a Chinese rural area.

To investigate the association between lead powder use, as folk skin care, and blood lead level (BLL) in children, we studied 222 children up to 14-years old living in a Chinese rural area and administered a face to face interview with their parents to collect information on lead powder use and other potential exposure. We measured children's BLL at baseline and 2 years later after an intervention. The children were divided into three categories according to their use of lead powder: regular use, irregular use and never use. We applied multivariate linear regression to determine the association between lead powder use and elevated BLL. The average BLL of all children was 18 µg/dl; 56% of them had BLL of 10 µg/dl or higher. Lead powder use was significantly associated with elevated BLL. After adjusting for potential confounders the BLL of regular and irregular users was higher than non-users by 3.11 µg/dl and 1.47 µg/dl, respectively. Duration of lead powder use was positively associated with BLL, but the time since last use was inversely associated. A significant BLL reduction was observed 2 years later, and the greatest reduction (21 µg/dl) was seen in the youngest group of regular users. This study showed that traditional use of lead powder for a skin care purpose was a major contributor to elevated BLL in these children.

Residual beneficial effects after a 3-year integrated intervention on stroke in China: a 10-year prospective follow-up.

OBJECTIVES: To evaluate whether an intervention program designed to reduce stroke incidence would have long-term residual effects on reducing all-cause and cause-specific mortalities, including cancer 10 years after the intervention was completed. METHODS: This is a posttrial analysis. We prospectively observed the mortality of a community-based trial of primary prevention of stroke in China performed between July 1987 and June 1990 by extending the follow-up to 30 June 2000. At the baseline, 26,607 adults aged 35 years or above and free from stroke were recruited from five cites of mainland China; 13,212 and 13,395 were assigned into intervention and control group, respectively. Participants in intervention group received a regularly integrated intervention including lifestyle intervention and hypertensive drug treatment. The controls did not receive intervention provided by the investigators. RESULTS: During the 10-year posttrial follow-up period, we observed a significant reduction on overall deaths [hazard ratio 0.91; 95% confidence interval (CI) 0.83, 0.99] and stroke mortality (hazard ratio 0.79; 95% CI 0.63, 1.00). An insignificant late trial beneficial effect was observed for hypertensive disease (hazard ratio 0.69; 95% CI 0.30, 1.58), ischemic heart disease (hazard ratio 0.87; 95% CI 0.64, 1.17), other nonmalignant diseases, and most cancer sites. CONCLUSION: This study demonstrates that a 3-year integrated intervention program successful for stroke prevention had long-term residual beneficial effects on reducing overall disease burdens among urban Chinese population, especially for the deaths from stroke. However, whether the integrated intervention also leads to reduced mortality of cardiovascular diseases and cancer would have to be confirmed by future larger studies.

Association of occupational stress and social support with health-related behaviors among chinese offshore oil workers.

To explore the relationship of occupational stress and social support with health-related behaviors of smoking, alcohol usage and physical inactivity, a cross-sectional survey was conducted among 561 offshore oil installation workers of a Chinese state-owned oil company. They were investigated with a self-administered questionnaire about socio-demographic characteristics, occupational stress, social support and health-related behaviors. Logistic regression analysis was used to study the association between occupational stress, social support and health-related behaviors and adjusted for age, educational level, marital status, duration of offshore work and job title. Of 561 workers, 218 (38.9%) were current smokers, 124 (22.1%) current drinkers, and 354 (63.1%) physically inactive in their leisure time. Further multivariate logistic regression analysis indicated that: (1) Current smoking was significantly negatively related with perceived stress from "Safety" (OR=0.74; 95% CI=0.58-0.94) and lack of supervisors' instrumental support (OR=0.34; 95% CI=0.18-0.65); (2) Current drinking was significantly positively related to perceived stress from "Interface between job and family/social life" (OR=1.32; 95% CI=1.02-1.70) and "Organizational structure" (OR=1.35; 95% CI=1.06-1.74), but was significantly negatively related to poor emotional support from friends (OR=0.54; 95% CI=0.62-0.96); (3) Physical inactivity after work was significantly positively associated with perceived stress from "Safety" (OR=1.44; 95% CI=1.16-1.79) and lack of instrumental support from both supervisors (OR=1.74; 95% CI=1.16-2.65) and friends (OR=1.68; 95% CI=1.06-2.42). The findings suggest that psychosocial factors of occupational stress and social support at offshore oil work might affect workers' health-related behaviors in different ways.