History of lung disease and risk of lung cancer in a population with high household fuel combustion exposures in rural China

Pulmonary Tuberculosis and Risk of Lung Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

Lung cancer is a leading cause of cancer-related deaths worldwide, with rising incidence in resource-limited settings. Research suggests an increased risk of lung cancer in individuals with a history of pulmonary tuberculosis (TB), but the association needs further clarification. This systematic review aims to provide a more comprehensive understanding of this relationship.

METHODS

We systematically searched the PubMed/Medline, EMBASE, and Scopus databases for relevant studies up to March 15, 2024. The quality of the included studies was assessed using the Joanna Briggs Institute (JBI) critical appraisal checklist. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using either random-effects or fixed-effects models, depending on the level of heterogeneity. All statistical analyses were performed using Comprehensive Meta-Analysis Software, version 3.0.

RESULTS

A total of 37 studies were included (9 cohort and 28 case-control). A significant association between prior pulmonary TB and lung cancer was found in both cohort (OR: 2.3; 95% CI, 1.4-3.8) and case-control (OR: 1.9; 95% CI, 1.4-2.5) studies. Subgroup analyses revealed a stronger association in East Asia (OR: 2.4; 95% CI, 1.3-4.1).

CONCLUSION

Our study provides strong evidence of an increased risk of lung cancer following pulmonary TB. The findings emphasize the need for comprehensive public health strategies, including targeted screening, early detection, and smoking cessation. Future studies should investigate the mechanisms linking TB and lung cancer, as well as the effectiveness of integrated prevention programs, particularly in high-burden regions.

Increased Lung Cancer Risk and Associated Risk Factors in Tuberculosis Survivors: A Korean Population-Based Study

BACKGROUND

Few studies have comprehensively evaluated the risk of lung cancer in tuberculosis survivors with consideration of smoking status and chronic obstructive pulmonary disease (COPD). Furthermore, little is known about lung cancer risk factors in tuberculosis survivors.

METHODS

This population-based cohort study enrolled tuberculosis survivors (n = 75 467) between 2010 and 2017 and 1:1 age- and sex-matched controls. Subjects were followed up for 1 year from the date of tuberculosis diagnosis to the date of the incident lung cancer, death, or December 2018, whichever came first. The risk of lung cancer was evaluated according to smoking and COPD status. We also evaluated the risk factors for lung cancer and developed an individualized lung cancer prediction model for tuberculosis survivors.

RESULTS

During a median follow-up duration of 4.8 years, the incident lung cancer risk was 1.72-fold higher in tuberculosis survivors than in the controls. Among tuberculosis survivors, those who were current smokers with ≥20 pack-years showed the highest risk of lung cancer (adjusted hazard ratio, 6.78) compared with never-smoker, non-tuberculosis-infected controls. tuberculosis survivors with COPD had a higher risk (2.43) than non-COPD, non-tuberculosis-infected controls. Risk factors for lung cancer in tuberculosis survivors were pulmonary tuberculosis, age >60 years, smoking, and the presence of COPD or asthma. The individualized lung cancer risk model showed good discrimination (concordance statistic = 0.827).

CONCLUSIONS

Previous tuberculosis infection is an independent risk factor regardless of smoking status or amount and COPD. Closer monitoring of tuberculosis survivors, especially heavy smokers or those with COPD, is needed for early lung cancer diagnosis.

Lung cancer occurrence after an episode of tuberculosis: a systematic review and meta-analysis

INTRODUCTION

People with tuberculosis experience long-term health effects beyond cure, including chronic respiratory diseases. We investigated whether tuberculosis is a risk factor for subsequent lung cancer.

METHODS

We searched PubMed, Scopus, Cochrane, Latin American and Caribbean Health Sciences Literature and the Scientific Electronic Library Online for cohort and case-control studies providing effect estimates for the association between tuberculosis and subsequent lung cancer. We pooled estimates through random-effects meta-analysis. The study was registered in PROSPERO (CDR42020178362).

RESULTS

Out of 6240 records, we included 29 cohort and 44 case-control studies. Pooled estimates adjusted for age and smoking (assessed quantitatively) were hazard ratio (HR) 1.51 (95% CI 1.30-1.76, I²=81%; five studies) and OR 1.74 (95% CI 1.42-2.13, I²=59%; 19 studies). The occurrence of lung cancer was increased for 2 years after tuberculosis diagnosis (HR 5.01, 95% CI 3.64-6.89; two studies), but decreased thereafter. Most studies were retrospective, had moderate to high risk of bias, and did not control for passive smoking, environmental exposure and socioeconomic status. Heterogeneity was high.

CONCLUSION

We document an association between tuberculosis and lung cancer occurrence, particularly in, but not limited to, the first 2 years after tuberculosis diagnosis. Some cancer cases may have been present at the time of tuberculosis diagnosis and therefore causality cannot be ascertained. Prospective studies controlling for key confounding factors are needed to identify which tuberculosis patients are at the highest risk, as well as cost-effective approaches to mitigate such risk.

Pulmonary Tuberculosis and Risk of Lung Cancer: A Systematic Review and Meta-Analysis

Pulmonary tuberculosis (TB) is a known risk factor for lung cancer. However, a detailed analysis of lung cancer type, age, sex, smoking, and TB burden associated with geographic and socioeconomic status has not been performed previously. We systematically appraised relevant observational studies reporting an association between pulmonary TB and lung cancer. All studies were included in the primary analysis, and studies that used robust TB diagnostic methods, such as validated medical diagnostic codes, were included in the secondary analysis. Thirty-two articles were included. The association between the history of pulmonary TB and diagnosis of lung cancer was statistically significant (OR 2.09, 95% CI: 1.62–2.69, p < 0.001). There was a high heterogeneity (I² = 95%), without any publication bias. The analysis indicated a high association in advanced articles describing stringent pulmonary TB diagnosis (OR 2.26, 95% CI: 1.29–3.94, p = 0.004). The subgroup analyses suggested a significant association in countries with medium or high TB burdens, from East Asia and the Pacific region, and upper-middle income countries. Heterogeneity within the subgroups remained high in a majority of the subgroup analyses. A meta-regression analysis revealed that younger patients showed a significantly higher association between TB and lung cancer (regression coefficient = 0.949, p < 0.001). The history of pulmonary TB is an independent risk factor for lung cancer, especially in younger patients diagnosed with pulmonary TB. Clinicians should be aware of this association while treating young patients with a history of pulmonary TB.

Approval Research for Carcinogen Humic-Like Substances (HULIS) Emitted from Residential Coal Combustion in High Lung Cancer Incidence Areas of China

The incidence and mortality rate of lung cancer is the highest in Xuanwei County, Yunnan Province, China. The mechanisms of the high lung incidence remain unclear, necessitating further study. However, the particle size distribution characteristics of HULIS emitted from residential coal combustion (RCC) have not been studied in Xuanwei. In this study, six kinds of residential coal were collected. Size-resolved particles emitted from the coal were sampled by using a burning system, which was simulated according to RCC made in our laboratory. Organic carbon (OC), elemental carbon (EC), water-soluble inorganic ion, water-soluble potentially toxic metals (WSPTMs), water-soluble organic carbon (WSOC), and HULIS-C (referred to as HULIS containing carbon contents) in the different size-segregated particulate matter (PM) samples were determined for health risk assessments by inhalation of PM. In our study, the ratio of HULIS-Cx to WSOCx values in RCC particles were 32.73–63.76% (average 53.85 ± 12.12%) for PM2.0 and 33.91–82.67% (average 57.06 ± 17.32%) for PM2.0~7.0, respectively. The carcinogenic risks of WSPTMs for both children and adults exceeded the acceptable level (1 × 10−6, indicating that we should pay more attention to these WSPTMs). Exploring the HULIS content and particle size distribution of the particulate matter produced by household coal combustion provides a new perspective and evidence for revealing the high incidence of lung cancer in Xuanwei, China.

Particle-induced oxidative damage by indoor size-segregated particulate matter from coal-burning homes in the Xuanwei lung cancer epidemic area, Yunnan Province, China

Size-segregated samples of airborne particulate matter were collected at the coal-burning homes of the Hutou high lung cancer epidemic village and a comparison site Xize village of the Xuanwei County, Yuanan Province, by an Anderson Cascade Impact Sampler in winter and spring to study the toxicological characteristics of different-sized particles. The DNA damage caused by the water-soluble fractions of these size-segregated particles was analyzed by the plasmid scission assay, and the trace element compositions were determined by Inductively Coupled Plasma Mass Spectrometry. The DNA damage rate from the airborne particles in the high lung cancer incidence area was higher than that in Xize village. The different-sized particles have highly varying DNA damage rates, with the values being greater in the small size range than in the large size range. The particle-induced DNA damage rates had a significantly positive correlation with total water-soluble trace elements. Further analysis of the individual elements indicated that the water-soluble heavy metals Zn, Cu, Cd, Rb, Cs, and Sb had a positive correlation with the particle-induced DNA damage, implying that these water-soluble heavy metals played an important role in the DNA damage. The Sr had a negative correlation with the particle-induced DNA damage, suggesting that the water-soluble Sr might counter DNA damage. The mass concentrations of the total and individual water-soluble trace elements were mostly enriched in the small particle size ranges, thus implying the indoor airborne particles in the small size ranges would have a higher health risk.

Daily cooking duration and its joint effects with genetic polymorphisms on lung cancer incidence: Results from a Chinese prospective cohort study

OBJECTIVES

In this study, we conducted a prospective cohort study to investigate the joint effects of daily cooking duration with single nucleotide polymorphisms (SNPs) on lung cancer incidence.

MATERIALS AND METHODS

A total of 33,868 individuals recruited in 2013 from Dongfeng-Tongji cohort study were included in our research, in which 5178 participants were genotyped. Daily cooking duration was accessed by questionnaire, and the incident lung cancer cases were confirmed. Fifteen lung cancer related SNPs were selected according to the previous reports. We used the multiple Cox regression models to evaluate the separate and joint effects of daily cooking duration and SNPs on lung cancer incidence.

RESULTS

Each 1-h increase in daily cooking duration was associated with a 17% elevated risk of lung cancer incidence [hazard ratio (HR) (95%CI) = 1.17(1.03, 1.33)]. Specifically, subjects with daily cooking duration >2 h/day had a 2.05-fold increased incident risk of lung cancer than those without cooking [HR(95%CI) = 2.05(1.20, 3.53)] (P_trend = 0.011). The rs2395185 and rs3817963, both located at 6p21.32, were significantly associated with lung cancer incidence. Compared with no cooking subjects with rs2395185GG or rs3817963TT genotype, subjects with daily cooking >2 h/day and carrying rs2395185GT + TT genotypes had a 2.48-fold increased risk of lung cancer [HR(95%CI) = 2.48(1.03, 5.97)], and there were significant joint effects of rs3817963TC + CC with daily cooking 1-2 and >2 h/day [HR(95%CI) = 2.23(1.07, 4.64) and 2.22(1.05, 4.68), respectively].

CONCLUSIONS

Longer daily cooking duration, especially daily cooking >2 h/day, was associated with increased risk of lung cancer. There were significant joint effects of rs2395185 and rs3817963 with daily cooking duration on lung cancer incidence. This study offered a new indicator of cooking related pollution exposure and added new evidence for the joint effects of environment and genetic factors on lung cancer incidence.

Assessment of natural radioactivity in coals and coal combustion residues from a coal-based thermoelectric plant in Bangladesh: implications for radiological health hazards

To study the level of radioactivity concentrations from a coal-based power plant (Barapukuria, Bangladesh) and to estimate the associated radiological hazards, coal and associated combustion residuals from the power plant were analyzed by gamma-ray spectrometry with high-purity germanium (HPGe) detector. The results reveal that the mean radioactivity (Bq kg^-1) concentrations in feed coal samples are 66.5 ± 24.2, 41.7 ± 18.2, 62.5 ± 26.3, and 232.4 ± 227.2 for U-238, Ra-226, Th-232, and K-40, respectively, while in coal combustion residuals (CCRs), they are 206.3 ± 72.4, 140.5 ± 28.4, 201.7 ± 44.7, and 232.5 ± 43.8, respectively. With the exception of K-40, all the determined natural radionuclides are considerably higher in the investigated feed coal and associated combustion residues as compared with the world soil and world coal mean activities. On the average, CCRs contains 3.10-3.37 times more natural radionuclides than the feed coal, except for K-40. The radioactivity of fly ash and bottom ash is fractionated, and ratio ranges from 1.40 to 1.57. The mean values of the radiological hazard indices in the coal and their associated residuals are 153.1 and 446.8 Bq kg^-1 for radium equivalent activity, 0.41 and 1.21 for the external hazard index, 70 and 200.1 nGy h^-1 for the absorbed gamma dose rate, 0.09 and 0.25 mSv year^-1 for the annual effective dose rate, and 3.0 × 10^-4 and 8.6 × 10^-4 Sv^-1 for the excess lifetime cancer risk, respectively, most of which exceed the UNSCEAR-recommended respective threshold limits. The outcome of this study suggests a potential radiological threat to the environment as well as to the health of occupational workers and nearby inhabitants from the examined samples.

The Overlooked Occurrence of Environmentally Persistent Free Radicals in an Area with Low-Rank Coal Burning, Xuanwei, China

The mining and burning of low-rank coal in Xuanwei, China have attracted a great deal of research attention because of the generated polyaromatic hydrocarbons (PAHs) and the high incidence of lung cancer in this region. Given the abundant transition metals in the allitic soil, we hypothesized that environmentally persistent free radicals (EPFRs) are formed in this region and the potential risk had not been addressed. Strong electron paramagnetic resonance (EPR) signals of 3.20 × 10¹⁷ - 3.10 × 10¹⁹ spins/g were detected in environmental samples, including chimney soot, coal, soil and total suspended particles (TSP). These EPR signals did not significantly change after 18-months storage and had g-values in the range of 2.0039-2.0046, suggesting typical organic free radicals. Similar strong EPR signals were observed in PAH (anthracene and pyrene as model compounds) degradation on simulated soil particles and lasted over one month even when the applied PAHs were 100% degraded. Based on g-value and bond width, we propose that EPR signals detected in TSP and soot originated from both coal combustion and PAH photodegradation. Further research is thus urgently required to investigate EPFR generation, exposure and risk in Xuanwei to better understand the cause of high lung cancer incidence.

Life expectancy impacts due to heating energy utilization in China: Distribution, relations, and policy implications

The relation between life expectancy and energy utilization is of particular concern. Different viewpoints concerned the health impacts of heating policy in China. However, it is still obscure that what kind of heating energy or what pattern of heating methods is the most related with the difference of life expectancies in China. The aim of this paper is to comprehensively investigate the spatial relations between life expectancy at birth (LEB) and different heating energy utilization in China by using spatial autocorrelation models including global spatial autocorrelation, local spatial autocorrelation and hot spot analysis. The results showed that: (1) Most of heating energy exhibit a distinct north-south difference, such as central heating supply, stalks and domestic coal. Whereas spatial distribution of domestic natural gas and electricity exhibited west-east differences. (2) Consumption of central heating, stalks and domestic coal show obvious spatial dependence. Whereas firewood, natural gas and electricity did not show significant spatial autocorrelation. It exhibited an extinct south-north difference of heat supply, stalks and domestic coal which were identified to show significant positive spatial autocorrelation. (3) Central heating, residential boilers and natural gas did not show any significant correlations with LEB. While, the utilization of domestic coal and biomass showed significant negative correlations with LEB, and household electricity shows positive correlations. The utilization of domestic coal in China showed a negative effect on LEB, rather than central heating. To improve the solid fuel stoves and control consumption of domestic coal consumption and other low quality solid fuel is imperative to improve the public health level in China in the future.

Spatial Analysis of Regional Factors and Lung Cancer Mortality in China, 1973-2013

Background: China's lung cancer crude death rate has increased 6.9-fold from 1973 to 2014. During this time, the country experienced extremely rapid economic growth and social change. It is important to understand the effects of risk factors on lung cancer mortality (LCM) for better allocation of limited resources of cancer prevention and control in China.Methods: Using three nationwide mortality surveys from 1973 to 2005, Global Health Data Exchange data in 2013, three nationwide smoking surveys from 1984 to 2013, four population censuses from 1964 to 2000, and other datasets, we have compiled datasets and developed spatial random effect models to assess the association of various area-level-contributing factors on LCM. Spatial scan statistics are used to detect high-risk clusters of LCM.Results: LCM is higher in urban and more industrialized areas (RR = 1.17) compared with those in rural areas. The level of industrial development's effect is higher for men, which accounts for about 70% of all LCM. Smoking is positively associated with regional variation of LCM rates, and the effect is higher for women than for men.Conclusions: The geographic pattern of high LCM in China is different from that of Western countries. LCM is positively associated with higher socioeconomic status, with more urbanized areas at a higher level of industrial development.Impact: There is a need to further explore additional risk in the high-risk clusters. The study is about China, but this situation may happen in other countries experiencing rapid industrialization and other developing countries. Cancer Epidemiol Biomarkers Prev; 26(4); 569-77. ©2017 AACRSee all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences."

Emission of volatile organic compounds from domestic coal stove with the actual alternation of flaming and smoldering combustion processes

Volatile organic compounds (VOCs) emissions from the chimney of a prevailing domestic stove fuelled with raw bituminous coal were measured under flaming and smoldering combustion processes in a farmer's house. The results indicated that the concentrations of VOCs quickly increased after the coal loading and achieved their peak values in a few minutes. The peak concentrations of the VOCs under the smoldering combustion process were significantly higher than those under the flaming combustion process. Alkanes accounted for the largest proportion (43.05%) under the smoldering combustion, followed by aromatics (28.86%), alkenes (21.91%), carbonyls (5.81%) and acetylene (0.37%). The emission factors of the total VOCs under the smoldering combustion processes (5402.9 ± 2031.8 mg kg^-1) were nearly one order of magnitude greater than those under the flaming combustion processes (559.2 ± 385.9 mg kg^-1). Based on the VOCs emission factors obtained in this study and the regional domestic coal consumption, the total VOCs emissions from domestic coal stoves was roughly estimated to be 1.25 × 10⁸ kg a^-1 in the Beijing-Tianjin-Hebei region.

Modification of association between prior lung disease and lung cancer by inhaled arsenic: A prospective occupational-based cohort study in Yunnan, China

Arsenic and prior lung diseases have been shown to increase lung cancer risk; however, little is known about their joint effects. The aim of our study was to analyze the joint effects of inhaled arsenic and prior lung diseases on lung cancer risk within a occupational cohort. The interactions of prior lung diseases and inhaled arsenic were analyzed based on multiplicative and additive scales in the Cox proportional hazards model. Compared with low arsenic exposure and no history of asthma, the hazard ratios (HRs) of high arsenic exposure with asthma, high arsenic exposure without asthma and low arsenic exposure with asthma were 2.61 (95% CI: 1.71-4.00), 2.60 (95% CI: 1.93-3.51) and 2.49 (95% CI: 1.53-4.06), respectively. Based on the multiplicative scale in the Cox proportional hazards model, the HR of the interaction of asthma and arsenic on lung cancer risk was 0.45 (95% CI: 0.25-0.80). Based on the additive scale, the relative excess risk due to interaction between asthma and arsenic was -1.41 (95% CI: -2.81 to -0.02). Our study provides strong evidence that arsenic exposure is associated with lung cancer risk. A significant negative interaction between asthma and arsenic on lung cancer risk is observed.

Evaluation of Pulmonary Nodules: Clinical Practice Consensus Guidelines for Asia

BACKGROUND

American College of Chest Physicians (CHEST) clinical practice guidelines on the evaluation of pulmonary nodules may have low adoption among clinicians in Asian countries. Unique patient characteristics of Asian patients affect the diagnostic evaluation of pulmonary nodules. The objective of these clinical practice guidelines was to adapt those of CHEST to provide consensus-based recommendations relevant to practitioners in Asia.

METHODS

A modified ADAPTE process was used by a multidisciplinary group of pulmonologists and thoracic surgeons in Asia. An initial panel meeting analyzed all CHEST recommendations to achieve consensus on recommendations and identify areas that required further investigation before consensus could be achieved. Revised recommendations were circulated to panel members for iterative review and redrafting to develop the final guidelines.

RESULTS

Evaluation of pulmonary nodules in Asia broadly follows those of the CHEST guidelines with important caveats. Practitioners should be aware of the risk of lung cancer caused by high levels of indoor and outdoor air pollution, as well as the high incidence of adenocarcinoma in female nonsmokers. Furthermore, the high prevalence of granulomatous disease and other infectious causes of pulmonary nodules need to be considered. Therefore, diagnostic risk calculators developed in non-Asian patients may not be applicable. Overall, longer surveillance of nodules than those recommended by CHEST should be considered.

CONCLUSIONS

TB in Asia favors lesser reliance on PET scanning and greater use of nonsurgical biopsy over surgical diagnosis or surveillance. Practitioners in Asia are encouraged to use these adapted consensus guidelines to facilitate consistent evaluation of pulmonary nodules.

The mortality patterns of lung cancer between 1990 and 2013 in Xuanwei, China

OBJECTIVES

To explore the variations in the mortality trends, especially death due to lung cancer, from 1990 to 2013 in Xuanwei City.

MATERIALS AND METHODS

Mortality data were collected in Xuanwei during the 2nd and 3rd National Retrospective Sampling Survey on Mortality and Routine Death Registration System (DRS) during 2011-2013. According to the result of the survey on under-reported deaths, mortality data from DRS during 2011-2013 were adjusted. Disease specific mortality rate, age-standardized mortality rate (ASMR) and 45Q15 were calculated in Xuanwei and compared with those in rural areas of China.

RESULTS

During three periods, 1990-1992, 2004-2005 and 2011-2013, lung cancer contributed to 56.86%, 58.45% and 63.03% of deaths from all cancers respectively with a much higher proportion than rural areas nationally. The ASMR of lung cancer for males surged from 41.43/10(5) to 88.17/10(5) during 1990-2005 and it surged from 37.70/10(5) to 74.45/10(5) for females. Although they declined slightly during 2011-2013 (82.53/10(5) and 62.62/10(5) for males and females respectively), the ASMR of lung cancer among males in Xuanwei was three times of that in rural areas in China, and it was six times higher among females. The 45Q15 of lung cancer for males in Xuanwei was 3-5 times of that in rural areas of China and for females it was 7-9 times. The high-mortality areas of lung cancer were still located in Laibin, Longchang, Wanshui and Shuanglong Communities. High-mortality areas of lung cancer expanded to their surrounding areas and those in southeast.

CONCLUSIONS

Although indoor air pollution caused by smoky coal has been fairly well controlled, patterns of death due to lung cancer have not obviously changed. The mortality rate of lung cancer among females was similar to that among males. Therefore, further studies should be conducted to comprehensively explore the risk factors of lung cancer in Xuanwei.

Household Solid Fuel Use and Cardiovascular Disease in Rural Areas in Shanxi, China

BACKGROUND

More than 80 percent of the China's population is located in the rural areas, 95 percent of which use coal, wood etc for cooking and heating. Limited by data availability, the association between household solid fuels and cardiovascular diseases (CVDs) in China's rural areas is ignored in prior studies.

METHODS

This cross sectional study was conducted from 2010-2012 and carried out on rural population aging 20-80 yr, comprised of 13877 participants from eighteen villages. Self-report questionnaire data were collected. Each outcome represents whether the participant has a kind of CVDs or not and it is reported in participants' questionnaire. Then the collected data is analyzed by logistic regression models with odds ratios (OR) and 95 percent confidence interval.

RESULTS

After adjusting for potential confounders, the use of household solid fuels was significantly associated with an increased risk for hypertension (OR 1.751), CHD (OR 2.251), stroke (OR 1.642), diabetes (OR 1.975) and dyslipidemia (OR 1.185). Residents with the highest tertile of the duration of household solid fuel exposure had an increased odd of hypertension (OR 1.651), stroke (OR 1.812), diabetes (OR 2.891) and dyslipidemia (OR 1.756) compared with those in the lowest tertile of the duration of solid fuel exposure.

CONCLUSION

Indoor pollution exposure from household solid fuels combustion may be a positive risk factor for CVDs in the perspectives of China's rural population. Our findings should be corroborated in longitudinal studies.

Lung cancer molecular epidemiology in China: recent trends

Lung cancer is both the most common diagnosed cancer and the leading cause of cancer related deaths in China. During the past three decades, the incidence and mortality of lung cancer in China are increasing rapidly. According to data from National Central Cancer Registry (NCCR) in 2010, the crude incidence of lung cancer in China was 46.08 per 100,000 population (61.86 per 100,000 men and 29.54 per 100,000 women), with an estimated over 600,000 new diagnosed lung cancer patients (416,333 males and 189,613 females). Meanwhile, the crude mortality of lung cancer in China was 37.00 per 100,000 population (50.04 per 100,000 men and 23.33 per 100,000 women). Consistent with the change in developed countries, adenocarcinoma has become the most predominant histological subtype of lung cancer in China. For the majority advanced non-small-cell lung cancer (NSCLC) patients, especially patients with adenocarcinoma, targeted therapy became increasing important in the treatment. Chinese researcher have done a lot work in terms of lung cancer molecular epidemiology, therefore, in this review, we further summarized the epidemiology of driver genes in NSCLC, hoping to help clinicians to better screen certain driver genes in China for treatment decisions.

The potential role of lung microbiota in lung cancer attributed to household coal burning exposures

Bacteria influence site-specific disease etiology and the host's ability to metabolize xenobiotics, such as polycyclic aromatic hydrocarbons (PAHs). Lung cancer in Xuanwei, China has been attributed to PAH-rich household air pollution from burning coal. This study seeks to explore the role of lung microbiota in lung cancer among never smoking Xuanwei women and how coal burning may influence these associations. DNA from sputum and buccal samples of never smoking lung cancer cases (n = 8, in duplicate) and controls (n = 8, in duplicate) in two Xuanwei villages was extracted using a multi-step enzymatic and physical lysis, followed by a standardized clean-up. V1-V2 regions of 16S rRNA genes were PCR-amplified. Purified amplicons were sequenced by 454 FLX Titanium pyrosequencing and high-quality sequences were evaluated for diversity and taxonomic membership. Bacterial diversity among cases and controls was similar in buccal samples (P = 0.46), but significantly different in sputum samples (P = 0.038). In sputum, Granulicatella (6.1 vs. 2.0%; P = 0.0016), Abiotrophia (1.5 vs. 0.085%; P = 0.0036), and Streptococcus (40.1 vs. 19.8%; P = 0.0142) were enriched in cases compared with controls. Sputum samples had on average 488.25 species-level OTUs in the flora of cases who used smoky coal (PAH-rich) compared with 352.5 OTUs among cases who used smokeless coal (PAH-poor; P = 0.047). These differences were explained by the Bacilli species (Streptococcus infantis and Streptococcus anginosus). Our small study suggests that never smoking lung cancer cases have differing sputum microbiota than controls. Further, bacteria found in sputum may be influenced by environmental exposures associated with the type of coal burned in the home.