Corrigendum: Evaluation of N95 respirators on fit rate, real-time leakage, and usability among Chinese healthcare workers: study protocol of a randomized crossover trial.

[This corrects the article DOI: 10.3389/fpubh.2023.1266607.].

Evaluation of N95 respirators on fit rate, real-time leakage, and usability among Chinese healthcare workers: study protocol of a randomized crossover trial.

Background: N95 respirators are used to limit the transmission of respiratory viruses in clinical settings. There are two to three major types of N95 available for all healthcare workers in Hong Kong. However, after the coronavirus outbreak and the consequent shortage of many commonly used respirators, several new N95 respirators were adopted temporarily in clinical settings without evaluation. Prior literature indicates that traditional N95 respirators used in hospitals in Hong Kong are not fit for Chinese people and have fit rates ranging from 50 to 60%. This study aims to investigate and compare the fit rate, real-time leakage, and mask usability of traditional and new N95 respirators among Chinese healthcare workers. Methods: This study will employ two sequential phases. Phase 1 has a cross-sectional exploratory design used to investigate the fit rate and mask usability of three types of respirators. Phase 2 will examine the effectiveness of respiratory protection by comparing traditional and new N95 respirators by a randomized crossover trial. Eligible participants will be randomly allocated through a controlled crossover experiment to either a traditional or new respirator group (n = 100 in each arm) for performing standard clinical procedures. The primary outcome (real-time leakage) will be recorded at 30 s intervals during nasopharyngeal suctioning and cardiopulmonary resuscitation. The secondary outcomes are the fit rate and mask usability. After a 2 min suctioning (15 s twice) and 4 min one-person CPR, the fit rate (assessed by standard N95 fit testing) and mask usability (measured by self-reported mask usability scale) will be recorded as data of post-procedure. After 10 min rest, measurement of real-time leakage (i.e., crossover), fit test, and usability will be repeated. Discussion: The result of real-time leakage will be a vital indicator of the respiratory protection of Chinese healthcare workers while performing prevalent clinical procedures, such as resuscitation. The fit rate and usability result will serve as an essential reference for consumable purchase policy in clinical settings.Trial registration: ISRCTN registry: ISRCTN40115047. Retrospectively registered on May 9, 2023. https://www.isrctn.com/ISRCTN40115047.

Risk assessment and prediction for lung cancer among Hong Kong Chinese men.

OBJECTIVE: Most of the previous risk prediction models for lung cancer were developed from smokers, with discriminatory power ranging from 0.57 to 0.72. We constructed an individual risk prediction model for lung cancer among the male general population of Hong Kong. METHODS: Epidemiological data of 1,069 histology confirmed male lung cancer cases and 1,208 community controls were included in this analysis. Residential radon exposure was retrospectively reconstructed based on individual lifetime residential information. Multivariable logistic regression with repeated cross-validation method was used to select optimal risk predictors for each prediction model for different smoking strata. Individual absolute risk for lung cancer was estimated by Gail model. Receiver-operator characteristic curves, area under the curve (AUC) and confusion matrix were evaluated to demonstrate the model performance and ability to differentiate cases from non-cases. RESULTS: Smoking and smoking cessation, education, lung disease history, family history of cancer, residential radon exposure, dietary habits, carcinogens exposure, mask use and dust control in workplace were selected as the risk predictors for lung cancer. The AUC of estimated absolute risk for all lung cancers was 0.735 (95% CI: 0.714-0.756). Using 2.83% as the cutoff point of absolute risk, the predictive accuracy, positive predictive value and negative predictive value were 0.715, 0.818 and 0.674, respectively. CONCLUSION: We developed a risk prediction model with moderate discrimination for lung cancer among Hong Kong males. External validation in other populations is warranted for this model in future studies.

Lung cancer risk in painters: results from the SYNERGY pooled case-control study consortium.

OBJECTIVES: We evaluated the risk of lung cancer associated with ever working as a painter, duration of employment and type of painter by histological subtype as well as joint effects with smoking, within the SYNERGY project. METHODS: Data were pooled from 16 participating case-control studies conducted internationally. Detailed individual occupational and smoking histories were available for 19 369 lung cancer cases (684 ever employed as painters) and 23 674 age-matched and sex-matched controls (532 painters). Multivariable unconditional logistic regression models were adjusted for age, sex, centre, cigarette pack-years, time-since-smoking cessation and lifetime work in other jobs that entailed exposure to lung carcinogens. RESULTS: Ever having worked as a painter was associated with an increased risk of lung cancer in men (OR 1.30; 95% CI 1.13 to 1.50). The association was strongest for construction and repair painters and the risk was elevated for all histological subtypes, although more evident for small cell and squamous cell lung cancer than for adenocarcinoma and large cell carcinoma. There was evidence of interaction on the additive scale between smoking and employment as a painter (relative excess risk due to interaction >0). CONCLUSIONS: Our results by type/industry of painter may aid future identification of causative agents or exposure scenarios to develop evidence-based practices for reducing harmful exposures in painters.

Smoking cessation sharply reduced lung cancer mortality in a historical cohort of 3185 Chinese silicotic workers from 1981 to 2014.

BACKGROUND: Population-based studies showed an over 50% decrease in lung cancer risk after quitting smoking for 5-6 years, but the beneficial effect in silicotics remains unknown. We aimed to rectify this knowledge gap using a large historical cohort of 3185 Chinese silicotics since 1981 and followed-up till 2014. METHODS: Baseline information on workers' socio-demographics, smoking habits, occupational history, and medical history was collected. Smoking status was reassessed during follow-up. Multiple Cox proportional hazards model was performed to evaluate the impact of smoking cessation on lung cancer mortality. RESULTS: Overall, 1942 deaths occurred and 188 lung cancer deaths were identified. Compared with never quitters, silicotics who were new quitters had almost halved their lung cancer risk [hazard ratio (HR) = 0.51, 95%CI: 0.34-0.76], while persistent quitters had a 53% risk reduction (HR = 0.47, 95%CI: 0.33-0.66). Lung cancer mortality approximately halved after quitting smoking for 10 years. While the risk kept decreasing with years since cessation, it did not reverse back to that of never smokers. Persistent quitters with small opacities tended to have higher beneficial effects than those with large opacities. CONCLUSIONS: Smoking cessation for 10 years halved lung cancer mortality among silicotics, while the beneficial effect was prominent for patients with small opacities.

Differential incidence trends of colon and rectal cancers in Hong Kong: an age-period-cohort analysis.

BACKGROUND: Colorectal cancer has been the second most common cancer among men and women in Hong Kong since 2012, but the underlying reasons for this increase remain unclear. We describe the incidence trend for colorectal cancer in Hong Kong to explore its etiology within this population. METHODS: The temporal trends in colorectal cancer incidence between 1983 and 2012 were analyzed with joinpoint regressions by sex, age groups, and anatomic sites among adults using data from the Hong Kong Cancer Registry. An age-period-cohort analysis was used to evaluate the effects of age, calendar periods, and birth cohorts on the observed temporal trends. RESULTS: The incidence of colon cancer among those aged 50 years and older in both sexes increased steadily from 1983 until the mid-1990s and was followed by a slight decrease thereafter, whereas the incidence among those aged 20-49 years decreased steadily from 1983 to 2012. In contrast, the incidence of rectal cancer steadily increased in men and remained stable in women throughout the study period. Significant period and birth cohort effects were observed for colon cancer, whereas period effects on the temporal trends were observed for male rectal cancer. CONCLUSIONS: The incidences of colon and rectal cancers have exhibited divergent patterns between 1983 and 2012 in Hong Kong, indicating heterogeneous etiologies between these two types of cancers. Surveillance of the risk factors related to colon and rectal cancers in the Hong Kong population should be performed, and the increased rectal cancer incidence in males is worthy of extra attention.

History of Asbestos Ban in Hong Kong.

As millions of immigrants moved to Hong Kong (HK) from China in the recent decades, large amount of residential housings were built in the early years and a substantial proportion of those buildings used asbestos-containing materials (ACMs). Since the number of new cases of ARDs diagnosed has increased year by year since 1990's, the remarkable increase of incidences had drawn the attention of the public and most importantly the HK government. It became one of the trigger points leading to asbestos ban in HK history. Comparatively, non-governmental organizations (NGOs), labor unions and patients' self-help organizations demonstrated a more aggressive and proactive attitude than the HK government and have played a key role in the development of asbestos banning policy in HK. After numerous petitions and meetings with the government representatives by those parties in the past decade, the HK government eventually changed its attitude and started to consider terminating the endless threat from asbestos by amending the policy, and the new clause of legislation for banning of all forms of asbestos was enacted on 4 April 2014. Other than the restriction of asbestos use, the compensation system about ARDs has also made some great moves by the effort of those parties as well. Based on the experience we learnt through the years, efforts from different stakeholders including patients' self-help organizations, NGOs, legislative councilors, and media power are absolutely essential to the success of progression and development in today's asbestos banning in HK.

Disparities of time trends and birth cohort effects on invasive breast cancer incidence in Shanghai and Hong Kong pre- and post-menopausal women.

BACKGROUND: Breast cancer is the leading cause of cancer morbidity among Shanghai and Hong Kong women, which contributes to 20-25% of new female cancer incidents. This study aimed to describe the temporal trend of breast cancer and interpret the potential effects on the observed secular trends. METHODS: Cancer incident data were obtained from the cancer registries. Age-standardized incidence rate was computed by the direct method using the World population of 2000. Average annual percentage change (AAPC) in incidence rate was estimated by the Joinpoint regression. Age, period and cohort effects were assessed by using a log-linear model with Poisson regression. RESULTS: During 1976-2009, an increasing trend of breast cancer incidence was observed, with an AAPC of 1.73 [95% confidence interval (CI): 1.54-1.92)] for women in Hong Kong and 2.83 (95% CI, 2.26-3.40) in Shanghai. Greater upward trends were revealed in Shanghai women aged 50 years old or above (AAPC = 3.09; 95% CI, 1.48-4.73). Using age at 50 years old as cut-point, strong birth cohort effects were shown in both pre- and post-menopausal women, though a more remarkable effect was suggested in Shanghai post-menopausal women. No evidence for a period effect was indicated. CONCLUSIONS: Incidence rate of breast cancer has been more speedy in Shanghai post-menopausal women than that of the Hong Kong women over the past 30 years. Decreased birth rate and increasing environmental exposures (e.g., light-at-night) over successive generations may have constituted major impacts on the birth cohort effects, especially for the post-menopausal breast cancer; further analytic studies are warranted.

Nighttime eating and breast cancer among Chinese women in Hong Kong.

BACKGROUND: A novel line of research suggests that eating at nighttime may have several metabolic consequences that are highly relevant to breast cancer. We investigated the association between nighttime eating habits after 10 p.m. and breast cancer in Hong Kong women. METHODS: A hospital-based case-control study was conducted during 2012-2015. A total of 922 patients with incident breast cancer (cases) and 913 hospital controls were recruited and interviewed using a standard questionnaire including information on eating behavior during both daytime and nighttime. We collected the timing, duration, types and frequencies of food intake of eating at nighttime. Odds ratios (ORs) for the risk of breast cancer in relation to nighttime eating-related variables were calculated by unconditional multivariable logistic regression. RESULTS: Eating at night after 10 pm was significantly associated with breast cancer with an adjusted OR of 1.50 (95% confidence interval (CI) 1.06-2.12, P = 0.02), and the associations were stronger in women who had the longest duration of nighttime eating (≥20 years) (adjusted OR = 2.28 (95% CI 1.13-4.61, P = 0.02) and who ate late (midnight to 2 a.m.) (adjusted OR = 2.73, 95% CI 1.01-6.99, P = 0.04). Interestingly, nighttime eating was only associated with breast cancer among women who consumed staple foods (OR = 2.16, 95% CI 1.42-3.29, P < 0.001) but not those who ate vegetables or fruits as nighttime meals. The significant association between nighttime eating and breast cancer was observed among women with body mass index (BMI) <25 (OR = 2.29, 95% CI 1.48-3.52, P < 0.001) but not among women with BMI ≥25. CONCLUSIONS: Results from this study suggest a possible association between nighttime eating behavior and breast cancer. These findings need to be confirmed by independent large studies.

Occupational risk factors for nasopharyngeal carcinoma in Hong Kong Chinese: a case-referent study.

PURPOSE: This study aimed to investigate the occupational risk factors for nasopharyngeal carcinoma (NPC) in Hong Kong Chinese. METHODS: We conducted a case-referent study with 352 incident cases and 410 referents recruited between June 2010 and December 2012. Full occupational histories were obtained via face-to-face interviews. Unconditional logistic regressions were performed to estimate the odds ratios (ORs) for NPC associated with occupational risk factors. RESULTS: Workers of craft related trades and elementary occupations were at elevated NPC risk with the adjusted ORs of 2.09 [95% confidence interval (CI) 1.09, 4.01] and 2.14 (95% CI 1.04, 4.41), respectively, compared with those clerical support workers as the reference group. Occupational exposures to cotton dust, chemical fumes, and welding fumes were significantly associated with increased NPC risk after adjustment for confounders [adjusted ORs (95% CIs) 1.93 (1.13, 3.28), 13.11 (1.53, 112.17), and 9.18 (1.05, 80.35), respectively]. We also observed significant exposure-response relationship for the duration of exposure to cotton dust (P for trend = 0.0175). Those with occupational exposure to cotton dust for 15 years or more were at significantly increased risk of NPC (adjusted OR 2.08, 95% CI 1.01, 4.28). CONCLUSIONS: This study indicates that employment in craft related trades and elementary occupations, as well as occupational exposures to chemical fumes, welding fumes, and cotton dust may be associated with an increased risk of NPC. Further epidemiological studies remain warranted to clarify the roles of specific occupational risk factors on NPC development.

Prognostic value of alcohol consumption and some other dietary habits for survival in a cohort of Chinese men with lung cancer.

BACKGROUND: Alcohol consumption and some other dietary habits are thought to be associated with lung cancer incidence. However, the effects of these habits on lung cancer prognosis have been studied rarely. The purpose of this study was to address these gaps in knowledge. METHODS: We studied a cohort of 1052 Chinese men in Hong Kong who were diagnosed with primary lung cancer. Cox proportional hazards models were used to determine the prognostic values of consumption of alcohol, fresh fruits or vegetables, meat, and fried or preserved food. RESULTS: Compared with never drinkers, men who drank alcohol 1-3 days per week had a more favorable lung cancer prognosis (hazard ratio [HR]: 0.82, 95% confidence interval [CI] 0.68-0.97); however, this survival advantage was not significant in men who drank alcohol more frequently (HR: 0.91, 95% CI 0.73-1.14). Compared with men who consumed preserved or fried food only occasionally, men who consumed these foods frequently had a higher risk of lung cancer mortality (HR: 1.20, 95% CI 1.00-1.42). CONCLUSIONS: Occasional consumption of alcohol was a favorable survival factor for Chinese men with lung cancer. However, this survival benefit did not exist for frequent drinkers of alcohol. Chinese men with lung cancer who were frequent consumers of fried or preserved food had a worse prognosis than those who consumed these foods only occasionally.

Lung Cancer Among Firefighters: Smoking-Adjusted Risk Estimates in a Pooled Analysis of Case-Control Studies.

OBJECTIVES: The aim of this study was to explore lung cancer risk among firefighters, with adjustment for smoking. METHODS: We used pooled information from the SYNERGY project including 14 case-control studies conducted in Europe, Canada, New Zealand, and China, with lifetime work histories and smoking habits for 14,748 cases of lung cancer and 17,543 controls. We estimated odds ratios by unconditional logistic regression with adjustment for smoking and having ever been employed in a job known to present an excess risk of lung cancer. RESULTS: There was no increased lung cancer risk overall or by specific cell type among firefighters (n = 190), neither before nor after smoking adjustment. We observed no significant exposure-response relationship in terms of work duration. CONCLUSIONS: We found no evidence of an excess lung cancer risk related to occupational exposure as a firefighter.

Secondhand Smoke Enhances Lung Cancer Risk in Male Smokers: An Interaction.

INTRODUCTION: Previous studies revealed that some indoor air pollutants and fine particle matter can interact with active smoking, enhancing lung cancer risk in smokers. Secondhand smoke (SHS), with remarkable differences from active smoking, contributes significantly to indoor air pollution and generates a considerable amount of fine particle matter, may cause a similar interaction with active smoking. METHODS: Information on lifetime SHS along with active smoking and other confirmed or suspected risk factors for lung cancer was collected in this case-referent study. Odds ratios and the 95% confidence intervals (95% CIs) of smoking status in different levels of SHS were evaluated. Potential multiplicative and additive interactions were explored. RESULTS: Compared with never-smokers without SHS, current smokers who were exposed to a high level of SHS demonstrated the highest odds ratio (15.13, 95% CI: 8.60, 26.65), almost doubles the effect in the current smokers without SHS. Significant additive interactions between current smoking and high level of SHS were observed for all lung cancers (synergy index = 1.80, 95% CI: 1.02, 3.24) and the squamous carcinoma subgroup. CONCLUSIONS: High level of SHS exposure greatly enhanced lung cancer risk among current smokers, consistent with an additive interaction; while this interaction was predominant for the squamous carcinoma. The results provide new evidence to the rationale of promoting global smoking cessation. IMPLICATIONS: Some indoor air pollutants can interact with active smoking, yielding a synergistic effect on inducing lung cancer. SHS, with noticeable differences from active smoking, is a major source of indoor air pollution. However, little has been known about the effect of SHS in smokers and whether there is a similar interaction between SHS and active smoking. In this study, we evaluated their separate and joint effects and indeed found a more than additive interaction between them. This finding suggests a potential problem of gathering smoking aggravating by venue restriction policies and re-advocates policy efforts on smoking cessation.

Exposure-response estimate for lung cancer and asbestosis in a predominantly chrysotile-exposed Chinese factory cohort.

BACKGROUND: Cumulative fiber exposures, predominantly chrysotile, were estimated in a Chinese asbestos worker cohort and exposure-response relationships with lung cancer mortality and cumulative incidence of asbestosis were determined. METHODS: Individual time-dependent cumulative exposures were estimated for 577 asbestos workers, followed prospectively for 37 years. Occupational history and smoking data were obtained from company records and personal interviews; vital status and causes of death were ascertained from death registries and hospital records. Hazard ratios were generated for disease outcomes, with adjustments for smoking and age. RESULTS: Median cumulative fiber exposure for the cohort was 132.6 fiber-years/ml (IQR 89.3-548.4). Exposure-response relationships were demonstrated for both disease outcomes, with nearly sixfold and threefold increased risks seen at the highest exposure level for lung cancer deaths and asbestosis, respectively. CONCLUSION: Evidence using quantitative exposure estimates was provided for increased risks of lung cancer mortality and development of asbestosis in a predominantly chrysotile-exposed cohort.

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.

Reproducibility and Validity of a Food Frequency Questionnaire for Assessing Dietary Consumption via the Dietary Pattern Method in a Chinese Rural Population.

OBJECTIVE: This study was conducted to assess the reproducibility and validity of a food frequency questionnaire (FFQ) that was developed to assess the overall dietary consumption via dietary pattern method in a rural population in southwest China. METHODS: A total of 179 participants aged between 40 and 70 years old were included in this study. Participants administered FFQ at baseline (FFQ1) and one year later (FFQ2) to assess the reproducibility. Six 3-day 24-hour recalls (24HRs) were completed between the administrations of two FFQs to determine the validity. Dietary patterns from three separate dietary sources were derived by using principle component factor analysis. Comparisons between dietary pattern scores were made by using Pearson or intraclass correlation coefficient, cross-classification analysis, weighted kappa (κ) statistic and Bland-Altman analysis. The de-attenuated method was adopted to correct the monthly and seasonally variation and the partial correlation analysis was used correct the influence by total energy intake. RESULTS: Two major dietary factors, labeled as prudent pattern and processed food pattern, were identified. The prudent pattern was characterized by higher factor loadings of wheat, rice, fresh vegetables, bean products, nuts, red meat, white meat and fresh eggs; and the processed food pattern was characterized by higher factor loadings of pickled vegetables, preserved vegetables and salted meat. Between Two FFQs, intraclass correlation coefficients were 0.57 for prudent pattern and 0.55 for processed food pattern, partial Pearson correlation coefficients were 0.51 for the prudent pattern and 0.56 for the processed food pattern; weighted κ statistic ranged from 0.45 (for the prudent pattern) to 0.56 (for the processed food pattern). Between FFQs and 24HRs, de-attenuated correlation coefficients ranged from 0.54 to 0.78 for the prudent pattern and from 0.55 to 0.61 for the processed food pattern; partial Pearson correlation coefficients ranged from 0.41 to 0.56 for the prudent pattern and from 0.42 to 0.44 for the processed food pattern; weighted κ statistic ranged from 0.42 to 0.46 for prudent pattern and from 0.43 to 0.60 for processed food pattern. The Bland-Altman plots and limits of agreement indicated that the deviation/divergence was not obvious for both of the patterns between FFQ1 and FFQ2 and between FFQs and 24HRs. CONCLUSION: The study suggests that the FFQ is reasonably reproducible and valid to assess the overall dietary consumption via dietary pattern methods in the Chinese rural population.

Prediction models and risk assessment for silicosis using a retrospective cohort study among workers exposed to silica in China.

This study aims to develop a prognostic risk prediction model for the development of silicosis among workers exposed to silica dust in China. The prediction model was performed by using retrospective cohort of 3,492 workers exposed to silica in an iron ore, with 33 years of follow-up. We developed a risk score system using a linear combination of the predictors weighted by the LASSO penalized Cox regression coefficients. The model's predictive accuracy was evaluated using time-dependent ROC curves. Six predictors were selected into the final prediction model (age at entry of the cohort, mean concentration of respirable silica, net years of dust exposure, smoking, illiteracy, and no. of jobs). We classified workers into three risk groups according to the quartile (Q1, Q3) of risk score; 203 (23.28%) incident silicosis cases were derived from the high risk group (risk score ≥ 5.91), whilst only 4 (0.46%) cases were from the low risk group (risk score < 3.97). The score system was regarded as accurate given the range of AUCs (83-96%). This study developed a unique score system with a good internal validity, which provides scientific guidance to the clinicians to identify high-risk workers, thus has important cost efficient implications.

Tobacco smoking, family history, and the risk of nasopharyngeal carcinoma: a case-referent study in Hong Kong Chinese.

PURPOSE: This study aimed to investigate the associations of tobacco smoking and family history of nasopharyngeal carcinoma (NPC) with the risk of NPC in Hong Kong Chinese. METHODS: Between June 2010 and December 2012, we conducted a case-referent study with 352 incident cases and 410 referents in Hong Kong. We collected information on tobacco smoking and family history of NPC via face-to-face interviews. RESULTS: There were 174 (49.4%) and 131 (32.0%) ever-smokers among cases and referents, respectively. The adjusted odds ratio (OR) for NPC related to current smoking was 1.67 [95% confidence interval (CI) 1.06, 2.61]. Exposure-response relationships were observed between years and total pack-years of smoking, and NPC risk (p = 0.001 and p = 0.018, respectively). History of NPC in first-degree relatives was associated with an increased NPC risk (adjusted OR = 4.52, 95% CI 2.39, 8.55). The increased NPC risk associated with sibling history (adjusted OR = 6.80, 95% CI 2.63, 17.56) was higher than that for parental history (adjusted OR = 3.04, 95% CI 1.27, 7.25). The adjusted OR for ever-smokers with family history using never-smokers without family history as the reference was 4.54 (95% CI 1.67, 12.34). CONCLUSIONS: This study verified the important roles of tobacco smoking and family history on NPC risk among Hong Kong Chinese. The provided evidence supported the knowledge that both environmental exposures and inherited susceptibility contributed to the risk of NPC.

Familial risks and estrogen receptor-positive breast cancer in Hong Kong Chinese women.

PURPOSE: The role of family history to the risk of breast cancer was analyzed by incorporating menopausal status in Hong Kong Chinese women, with a particular respect to the estrogen receptor-positive (ER+) type. METHODS: Seven hundred and forty seven breast cancer incident cases and 781 hospital controls who had completed information on family cancer history in first-degree relatives (nature father, mother, and siblings) were recruited. Odds ratio for breast cancer were calculated by unconditional multiple logistic regression, stratified by menopausal status (a surrogate of endogenous female sex hormone level and age) and type of relative affected with the disease. Further subgroup analysis by tumor type according to ER status was investigated. RESULTS: Altogether 52 (6.96%) breast cancer cases and 23 (2.95%) controls was found that the patients' one or more first-degree relatives had a history of breast cancer, showing an adjusted odds ratio (OR) of 2.41 (95%CI: 1.45-4.02). An excess risk of breast cancer was restricted to the ER+ tumor (OR = 2.43, 95% CI: 1.38-4.28), with a relatively higher risk associated with an affected mother (OR = 3.97, 95%CI: 1.46-10.79) than an affected sister (OR = 2.06, 95%CI: 1.07-3.97), while the relative risk was more prominent in the subgroup of pre-menopausal women. Compared with the breast cancer overall, the familial risks to the ER+ tumor increased progressively with the number of affected first-degree relatives. CONCLUSIONS: This study provides new insights on a relationship between family breast cancer history, menopausal status, and the ER+ breast cancer. A separate risk prediction model for ER+ tumor in Asian population is desired.

Lung cancer risk among cooks when accounting for tobacco smoking: a pooled analysis of case-control studies from Europe, Canada, New Zealand, and China.

OBJECTIVES: To investigate the risk of lung cancer among cooks, while controlling for smoking habits. METHODS: We used data from the SYNERGY project including pooled information on lifetime work histories and smoking habits from 16 case-control studies conducted in Europe, Canada, New Zealand, and China. RESULTS: Before adjustment for smoking, we observed an increased risk of lung cancer in male cooks, but not in female cooks. After adjusting, there was no increased risk and no significant exposure-response relationship. Nevertheless, subgroup analyses highlighted some possible excess risks of squamous cell carcinoma and small cell carcinoma in female cooks. CONCLUSIONS: There is evidence that lung cancer risks among cooks may be confounded by smoking. After adjustment, cooks did not experience an increased risk of lung cancer overall. The subgroup analyses showing some excess risks among female cooks require cautious interpretation.