Ie-Bin Lian

Possible association between nickel and chromium and oral cancer: A case–control study in central Taiwan

Oral cancer is one of the most common cancers in Taiwan. Changhua County, in central Taiwan, has an extremely high prevalence of oral cancer, along with a high concentration of metal-related industries and soil metal contamination. The aim of this study was to clarify the possible association between metals and oral cancer within this specific area. This study recruited 101 oral cancer patients and 104 controls from the Changhua Christian Hospital. All subjects completed a questionnaire that asked about demographic information; cigarette, alcohol, and betel quid use; and environmental and occupational exposure history. Blood samples were collected and tested for metal concentrations with inductively coupled plasma mass spectrometry. A multiple logistic regression model illustrated that oral cancer was significantly associated with the blood levels of nickel and chromium (both with P<0.0001) after controlling for potential confounders. This study suggested a potential role of these two metals in the mechanism of oral cancer development.

Progression of precancerous lesions to oral cancer: Results based on the Taiwan National Health Insurance Database

BACKGROUND Oral cancer (OC) is the leading cause of death from cancer in men between the ages of 25 and 44 in Taiwan. The survival rate for the last stage of OC is <20% while that for the earliest stage is >75%, which suggests the importance of the diagnosis of oral precancerous lesions (OPLs) in reducing OC mortality. The aim of this study was to analyze the time to OC event after OPL diagnosis, and to suggest the surveillance period necessary according to OPL type. MATERIALS AND METHODS This was a retrospective cohort study based on 1.0 million people randomly selected from the Taiwan National Health Insurance Database, which provided data on 3058 adult male patients aged ≥20 years who were diagnosed with OPL for the first time between 1996 and 2009. The patient population was divided into two groups according to the type of lesion: oral submucous fibrosis (OSF) or oral leukoplakia (OLE). Age-standardized incidence rate (ASIR) and hazards rate (HR) were then estimated. RESULTS The ASIR for OPL showed an increasing trend over the study period, the main contributor to this being OSF. The OSF group demonstrated a higher OC incidence rate than the OLE group. CONCLUSION Patients with both OLE and OSF carry a higher risk for OC than those with either OLE or OSF alone, and they may also experience malignant transformation at an earlier date (mostly within 5 years). The 5- and 10-year OC rate for both OLE and OSF was found to be 5% and around 10%, respectively. However, 10 years after the diagnosis of OPL, OSF carries a higher risk of developing into OC than OLE.

The incidence of varicella and herpes zoster in Taiwan during a period of increasing varicella vaccine coverage, 2000-2008.

The introduction and the widespread use of the varicella vaccine in Taiwan has led to a 75-80% decrease in the incidence of varicella in children. However the vaccines long-term impact on the incidence of herpes zoster (HZ) has attracted attention. By controlling gender, underlying diseases, and age effects, a Poisson regression was applied on the 2000-2008 chart records of 240 000 randomly selected residents who enrolled in the Universal National Health Insurance. The results show that, as the vaccine coverage in children increases, the incidence of varicella decreases. However, the incidence of HZ increased even before the implementation of the free varicella vaccination programme in 2004, particularly in females. The increase in the incidence of HZ cannot be entirely and directly attributed to the widespread vaccination of children. Continuous monitoring is needed to understand the secular trends in HZ before and after varicella vaccination in Taiwan and in other countries.

Quantification of betel quid chewing and cigarette smoking in oral cancer patients.

BACKGROUND Betel quid chewing and cigarette smoking are two of the risk factors for some dental diseases as well as oral cavity cancer in Taiwan. The aim of the study was to quantify these factors in oral cavity cancer patients and compare the prevalence of these factors in patients and the general population. METHODS A questionnaire was designed to evaluate betel quid chewing, cigarette smoking and alcohol drinking in 254 patients, who had squamous cell carcinoma of the oral cavity, and had received surgical excision at the Changhua Christian Hospital in Taiwan between 2005 and 2008. The results were compared with those of population of Taiwan, based on a nation-wide survey with sample of 26 744 people. RESULTS We found that more than 80% of the male patients were both betel quid chewers and smokers. Few women in the survey practiced betel quid chewing, cigarette smoking or alcohol drinking. Chewers and smokers usually started the habits in their 20s. On average, a chewer patient consumed 12 508 betel quid pieces per year, for 23.3 years before the diagnosis of oral cavity cancer, making the total amount of betel quid consumed nearly 310 000 pieces; and a smoker patient consumed 469 packs per year, for 28.5 years before diagnosis, making the total number of about 14 000 packs. Patients with both habits had the age at diagnosis 4 years earlier than the smoker-only patients, 5 years earlier than the chewer-only patients, and 6 years earlier than those with neither. CONCLUSIONS On average, it took two decades of betel quid chewing and cigarette smoking before oral cavity cancer diagnosis, making the life-time consumption of these substances an astonishing amount. Betel quid chewing and cigarette smoking patients are more likely to be diagnosed with oral cavity cancer at a younger age than those who have just one habit or none. Patients that smoke more are not only more likely to be diagnosed at a younger age, but also at an advanced stage.

Spatiotemporal trends in oral cancer mortality and potential risks associated with heavy metal content in Taiwan soil.

Central and Eastern Taiwan have alarmingly high oral cancer (OC) mortality rates, however, the effect of lifestyle factors such as betel chewing cannot fully explain the observed high-risk. Elevated concentrations of heavy metals in the soil reflect somewhat the levels of exposure to the human body, which may promote cancer development in local residents. This study assesses the space-time distribution of OC mortality in Taiwan, and its association with prime factors leading to soil heavy metal content. The current research obtained OC mortality data from the Atlas of Cancer Mortality in Taiwan, 1972–2001, and derived soil heavy metals content data from a nationwide survey carried out by ROCEPA in 1985. The exploratory data analyses showed that OC mortality rates in both genders had high spatial autocorrelation (Moran’s I = 0.6716 and 0.6318 for males and females). Factor analyses revealed three common factors (CFs) representing the major pattern of soil pollution in Taiwan. The results for Spatial Lag Models (SLM) showed that CF1 (Cr, Cu, Ni, and Zn) was most spatially related to male OC mortality which implicates that some metals in CF1 might play as promoters in OC etiology.

Reduction in arsenic intake from water has different impacts on lung cancer and bladder cancer in an arseniasis endemic area in Taiwan.

BackgroundExcessive arsenic intake has a detrimental effect on human health, as reflected in an increase in cancer incidence. In an area on the southwest coast of Taiwan, arsenic intake from well water since the 1920s had caused an exceptionally high mortality from cancer. Municipal water has become available to people living in the arseniasis endemic area since the early 1970s. This study explored the impacts of reduction in arsenic intake from water on lung cancer and bladder cancer in the arseniasis endemic area in Taiwan.MethodsChart records of 23,013 patients diagnosed with bladder cancer and 93,633 patients with lung cancer from 1979 to 2003 were retrieved from the Taiwan Cancer Registry Center. We used the age-period-cohort model to study the changes in the incidence of lung cancer and bladder cancer in the arseniasis endemic area and the rest of Taiwan.ResultsThree decades after municipal water supply to the arseniasis and black foot disease endemic area (BFDEA), we saw a marked decrease in the incidence of both bladder cancer and lung cancer in the area, especially for those in the later cohorts. The relative risk (RR) of getting a bladder cancer for people living in BFDEA when compared with those in the rest of Taiwan has dropped from 20 for the early cohorts to 5 for the late cohorts. As to lung cancer, the RR has decreased from 8 to between 1.5 and 2.ConclusionReduction in arsenic intake from water has a positive impact on the incidence of both lung and bladder cancer; however, while RR for lung cancer has dropped to below 2, RR for bladder cancer remained at around 5. The difference may be because (1) there are other risk factors beside the well-water intake or (2) bladder cancer may have longer latency period for excessive arsenic exposure than lung cancer. More studies are required to understand the causes behind the difference in RR for these two types of cancer.

Re-assess Vector Indices Threshold as an Early Warning Tool for Predicting Dengue Epidemic in a Dengue Non-endemic Country

Background Despite dengue dynamics being driven by complex interactions between human hosts, mosquito vectors and viruses that are influenced by climate factors, an operational model that will enable health authorities to anticipate the outbreak risk in a dengue non-endemic area has not been developed. The objectives of this study were to evaluate the temporal relationship between meteorological variables, entomological surveillance indices and confirmed dengue cases; and to establish the threshold for entomological surveillance indices including three mosquito larval indices [Breteau (BI), Container (CI) and House indices (HI)] and one adult index (AI) as an early warning tool for dengue epidemic. Methodology/Principal Findings Epidemiological, entomological and meteorological data were analyzed from 2005 to 2012 in Kaohsiung City, Taiwan. The successive waves of dengue outbreaks with different magnitudes were recorded in Kaohsiung City, and involved a dominant serotype during each epidemic. The annual indigenous dengue cases usually started from May to June and reached a peak in October to November. Vector data from 2005–2012 showed that the peak of the adult mosquito population was followed by a peak in the corresponding dengue activity with a lag period of 1–2 months. Therefore, we focused the analysis on the data from May to December and the high risk district, where the inspection of the immature and mature mosquitoes was carried out on a weekly basis and about 97.9% dengue cases occurred. The two-stage model was utilized here to estimate the risk and time-lag effect of annual dengue outbreaks in Taiwan. First, Poisson regression was used to select the optimal subset of variables and time-lags for predicting the number of dengue cases, and the final results of the multivariate analysis were selected based on the smallest AIC value. Next, each vector index models with selected variables were subjected to multiple logistic regression models to examine the accuracy of predicting the occurrence of dengue cases. The results suggested that Model-AI, BI, CI and HI predicted the occurrence of dengue cases with 83.8, 87.8, 88.3 and 88.4% accuracy, respectively. The predicting threshold based on individual Model-AI, BI, CI and HI was 0.97, 1.16, 1.79 and 0.997, respectively. Conclusion/Significance There was little evidence of quantifiable association among vector indices, meteorological factors and dengue transmission that could reliably be used for outbreak prediction. Our study here provided the proof-of-concept of how to search for the optimal model and determine the threshold for dengue epidemics. Since those factors used for prediction varied, depending on the ecology and herd immunity level under different geological areas, different thresholds may be developed for different countries using a similar structure of the two-stage model.

The changing epidemiology of varicella incidence after implementation of the one-dose varicella vaccination policy

The varicella vaccine has been available in the Taiwan market since July 1997. Beginning 1998-1999, Taipei City and Taichung City/County as the early launch areas included the varicella vaccine in their free pediatric vaccination programs. By contrast, the national free vaccination program was not implemented until 2004. We aim to investigate the changing epidemiology of varicella incidence through an analysis of age-period-cohort effects. With the greatest decrease in varicella incidence occurring in children aged below 6, the incidence of varicella shifted to older age groups as reflected in different birth cohorts. The current study provides important implications for the current vaccination policy.

Increased risk of coronary heart disease in male patients with central serous chorioretinopathy: results of a population-based cohort study.

Aims To investigate whether patients with central serous chorioretinopathy (CSCR) have increased risk of coronary heart disease (CHD). Methods Population-based retrospective cohort and case control study. Longitudinal data from the Taiwan National Health Insurance Research Database (2000–2009) were analysed. The study cohort comprised 835 patients with a diagnosis of CSCR and 4175 age and gender matched patients without CSCR. Kaplan–Meier plots and log-rank tests were used to compare differences in the hazard rates of CHD between the CSCR and non-CSCR cohorts. Stratified Cox proportional hazard models were applied to examine the association between CSCR and CHD, adjusting for potential confounding factors. Results The 5-year CHD cumulative incidence for patients with CSCR was nearly twofold that of the non-CSCR cohort (6.12% vs 3.29%, p=0.004) from the log-rank test. The adjusted CHD HR of CSCR versus non-CSCR was 1.61 (95% CI 1.12 to 2.30, p=0.009) from the Cox model. Specifically, the HR for male patients was 1.72 (95% CI 1.14 to 2.59, p=0.010) and for female patients it was 1.34 (95% CI 0.64 to 2.84, p=0.438). Conclusions Male patients with CSCR had a significantly higher CHD rate than those without CSCR, indicating that CSCR may be a potential risk factor for the development of CHD for men.

Epidemiology and clinical characteristics of rhegmatogenous retinal detachment in Taiwan

Purpose To estimate the incidence and clinical characteristics of rhegmatogenous retinal detachment (RRD) in Taiwan. Methods This was a nationwide, population-based retrospective study of patients with RRD. Data from the Taiwan National Health Insurance Research Database (2000–2012), which represents 4% of the total population in Taiwan, were analysed. The incidence of RRD and its associations with age, gender and high myopia were analysed. Results A total of 2359 patients with RRD (1336 men and 1023 women) were identified from 2000–2012. The age-standardised incidence rate of RRD over the 13-year period was 16.40±1.06 per 105 person-years (18.89 and 13.93 for men and women, respectively, p<0.0001) and an average age of 47.76±0.67 years. The incidence in both genders had an obvious peak at 50–69 years of age, and a secondary peak at 20–29 years in women. Concomitant high myopia was noted in 10.51% of the patients, with an average of 39.72±1.95 years. Prior cataract extraction was noted in 11.06% of the patients, including 17.64% in the patients RRD aged ≥50 years and 4.04% in those younger than 50 years. The average age of the patients with pseudophakic or aphakic RRD was 61.85±1.60 years. Conclusions The annual incidence of RRD in Taiwan is comparable to most Western countries, with a relatively younger mean age. The male patients were more susceptible to retinal detachment in almost all age groups. Retinal detachment in patients with high myopia was associated with a younger age at onset.