[Exploration and validation of optimal cut-off values for tPSA and fPSA/tPSA screening of prostate cancer at different ages]

Objective: To determine the total and age-specific cut-off values of total prostate specific antigen (tPSA) and the ratio of free PSA divided total PSA (fPSA/tPSA) for screening prostate cancer in China. Methods: Based on the Chinese Colorectal, Breast, Lung, Liver, and Stomach cancer Screening Trial (C-BLAST) and the Tianjin Common Cancer Case Cohort (TJ4C), males who were not diagnosed with any cancers at baseline since 2017 and received both tPSA and fPSA testes were selected. Based on Cox regression, the overall and age-specific (＜60, 60-＜70, and ≥70 years) accuracy and optimal cut-off values of tPSA and fPSA/tPSA ratio for screening prostate cancer were evaluated with time-dependent receiver operating characteristic curve (tdROC) and area under curve (AUC). Bootstrap resampling was used to internally validate the stability of the optimal cut-off value, and the PLCO study was used to externally validate the accuracy under different cut-off values. Results: A total of 5 180 participants were included in the study, and after a median follow-up of 1.48 years, a total of 332 prostate cancer patients were included. In the total population, the tdAUC of tPSA and fPSA/tPSA screening for prostate cancer were 0.852 and 0.748, respectively, with the optimal cut-off values of 5.08 ng/ml and 0.173, respectively. After age stratification, the age specific cut-off values of tPSA in the <60, 60-<70, and ≥70 age groups were 3.13, 4.82, and 11.54 ng/ml, respectively, while the age-specific cut-off values of fPSA/tPSA were 0.153, 0.135, and 0.130, respectively. Under the age-specific cut-off values, the sensitivities of tPSA screening for prostate cancer in males <60, 60-70, and ≥70 years old were 92.3%, 82.0%, and 77.6%, respectively, while the specificities were 84.7%, 81.3%, and 75.4%, respectively. The age-specific sensitivities of fPSA/tPSA for screening prostate cancer were 74.4%, 53.3%, and 55.9%, respectively, while the specificities were 83.8%, 83.7%, and 83.7%, respectively. Both bootstrap's internal validation and PLCO external validation provided similar results. The combination of tPSA and fPSA/tPSA could further improve the accuracy of screening. Conclusion: To improve the screening effects, it is recommended that age-specific cut-off values of tPSA and fPSA/tPSA should be used to screen for prostate cancer in the general risk population.

Daptomycin production enhancement by ARTP mutagenesis and fermentation optimization in Streptomyces roseosporus

AIMS

We evaluated whether the randomness of mutation breeding can be regulated through a double-reporter system. We hope that by establishing a new precursor feeding strategy, the production capacity of industrial microorganisms after pilot scale-up can be further improved.

METHODS AND RESULTS

In this study, the industrial strain Streptomyces roseosporus L2796 was used as the starter strain for daptomycin production, and a double-reporter system with the kanamycin resistance gene Neo and the chromogenic gene gusA was constructed to screen for high-yield strain L2201 through atmospheric and room temperature plasma (ARTP). Furthermore, the composition of the culture medium and the parameters of precursor replenishment were optimized, resulting in a significant enhancement of the daptomycin yield of the mutant strain L2201(752.67 mg/l).

CONCLUSIONS

This study successfully screened a high-yield strain of daptomycin through a double-reporter system combined with ARTP mutation. The expression level of two reporter genes can evaluate the strength of dptEp promoter, which can stimulate the expression level of dptE in the biosynthesis of daptomycin, thus producing more daptomycin. The developed multi-stage feeding rate strategy provides a novel way to increase daptomycin in industrial fermentation.

Identification and Characterization of a New Regulator, TagR, for Environmental Stress Resistance Based on the DNA Methylome of Streptomyces roseosporus

DNA methylation is a defense that microorganisms use against extreme environmental stress, and improving resistance against environmental stress is essential for industrial actinomycetes. However, research on strain optimization utilizing DNA methylation for breakthroughs is rare. Based on DNA methylome analysis and KEGG pathway assignment in Streptomyces roseosporus, we discovered an environmental stress resistance regulator, TagR. A series of in vivo and in vitro experiments identified TagR as a negative regulator, and it is the first reported regulator of the wall teichoic acid (WTA) ABC transport system. Further study showed that TagR had a positive self-regulatory loop and m4C methylation in the promoter improved its expression. The ΔtagR mutant exhibited better hyperosmotic resistance and higher decanoic acid tolerance than the wild type, which led to a 100% increase in the yield of daptomycin. Moreover, enhancing the expression of the WTA transporter resulted in better osmotic stress resistance in Streptomyces lividans TK24, indicating the potential for wide application of the TagR-WTA transporter regulatory pathway. This research confirmed the feasibility and effectiveness of mining regulators of environmental stress resistance based on the DNA methylome, characterized the mechanism of TagR, and improved the resistance and daptomycin yield of strains. Furthermore, this research provides a new perspective on the optimization of industrial actinomycetes. IMPORTANCE This study established a novel strategy for screening regulators of environmental stress resistance based on the DNA methylome and discovered a new regulator, TagR. The TagR-WTA transporter regulatory pathway improved the resistance and antibiotic yield of strains and has the potential for wide application. Our research provides a new perspective on the optimization and reconstruction of industrial actinomycetes.

Improving the Yield and Quality of Daptomycin in Streptomyces roseosporus by Multilevel Metabolic Engineering

Daptomycin is a cyclic lipopeptide antibiotic with a significant antibacterial action against antibiotic-resistant Gram-positive bacteria. Despite numerous attempts to enhance daptomycin yield throughout the years, the production remains unsatisfactory. This study reports the application of multilevel metabolic engineering strategies in Streptomyces roseosporus to reconstruct high-quality daptomycin overproducing strain L2797-VHb, including precursor engineering (i.e., refactoring kynurenine pathway), regulatory pathway reconstruction (i.e., knocking out negative regulatory genes arpA and phaR), byproduct engineering (i.e., removing pigment), multicopy biosynthetic gene cluster (BGC), and fermentation process engineering (i.e., enhancing O₂ supply). The daptomycin titer of L2797-VHb arrived at 113 mg/l with 565% higher comparing the starting strain L2790 (17 mg/l) in shake flasks and was further increased to 786 mg/l in 15 L fermenter. This multilevel metabolic engineering method not only effectively increases daptomycin production, but can also be applied to enhance antibiotic production in other industrial strains.

[Potential pleiotropism of cancer-related single nucleotide polymorphisms among Chinese population]

Objective: To investigate the potential pleiotropism of cancer-related single nucleotide polymorphisms (SNPs) among Chinese population. Methods: Based on the catalogue of GWAS jointly constructed by the National Human Genome Research Institute and the European Institute of Bioinformatics, according to population origin (Chinese population and non-Chinese population) and disease traits (cancer and non-cancer traits). All SNPs found by GWAS before August 2020 were divided into four categories: cancer in Chinese population, non-cancer in Chinese population, cancer in non-Chinese population and non-cancer in non-Chinese population. The number, correlation and linkage of the four categories of SNPs were described. Results: By August 2020, a total of 196 813 SNPs from 4 096 GWAS were included in the GWAS directory. The information that SNPs refer to unknown or were not related to the disease was excluded, and 117 441 independent SNPs were finally included. There were 619 SNPs related to cancer and 9 569 SNPs related to non-cancer disease in Chinese population, respectively. There were 4 624 SNPs related to cancer and 106 448 SNPs related to non-cancer disease (trait) in non-Chinese population, respectively. Three SNPs, rs2736100, rs6983267 and rs401681, were associated with two or more types of cancer in both Chinese and non-Chinese populations. Seven SNPs, rs7705526, rs2736100, rs10993994, rs2735839, rs4430796, rs174537 and rs9271588, were associated with cancer and non-cancer diseases in both Chinese and non-Chinese populations, respectively. Conclusion: There is a potential pleiotropism of cancer-related SNPs in Chinese population.

[Diagnostic performance of quantitative fecal immunochemical test in detection of advanced colorectal neoplasia]

Objective: To evaluate the diagnostic performance of quantitative fecal immunochemical testing (FIT) and to provide reference for designing effective colorectal cancer (CRC) screening strategy in China. Methods: Based on an ongoing randomized controlled trial comparing the colorectal cancer screening strategies, this current study involved 3 407 participants aged 50-74 years who had undergone colonoscopies. All the feces samples were collected from the participants prior to receiving the colonoscopy. Fecal hemoglobin (Hb) was tested by FIT following a standardized operation process. Diagnosis-related indicators of FIT were calculated using the colonoscopy results as the gold standard. Results: Among the 3 407 participants, the mean age (SD) as 60.5 (6.3) years and 1 753 (51.5%) were males. The participants involved 28 (0.8%) CRCs, 255 (7.5%) advanced adenomas, 677 (19.9%) nonadvanced adenomas, and 2 447 (71.8%) benign or negative findings. With an overall positivity rate of 2.8% (96/3 407) at the recommended cutoff value of 20 μg Hb/g, the sensitivities of FIT for both CRC and advanced adenoma were 57.1% (95%CI: 37.2%-75.5%) and 11.0% (95%CI: 7.4%-15.5%), respectively, with the corresponding specificity as 98.4% (95%CI: 97.8%-98.8%). At a decreased cut-off value of 5 μg Hb/g, the sensitivities for detecting CRC and advanced adenoma increased to 64.3% (95%CI: 44.1%-81.4%) and 16.5% (95%CI: 12.1%-21.6%), respectively, but the specificity reduced to 95.2% (95%CI: 94.4%-95.9%). The areas under the ROC curve for CRC and advanced adenoma were 0.908 (95%CI: 0.842-0.973) and 0.657 (95%CI: 0.621-0.692), respectively. Of the diagnostic performance, there were no significant differences noticed by different sex and age groups. Conclusions: In our study, the quantitative FIT showed modest sensitivity in detecting CRC but limited sensitivity in detecting advanced adenoma. In population-based CRC screening programs, the quantitative FIT had the advantage of adjusting the positive threshold based on the targeted detection rate and available resource load of colonoscopy.

[Total cholesterol and the risk of primary liver cancer in Chinese males: a prospective cohort study]

Objective: To investigate the association between total cholesterol (TC) and primary liver cancer in Chinese males. Methods: Since May 2006, all the male workers, including the employees and the retirees in Kailuan Group were recruited in the Kailuan male dynamic cohort study. Information about demographics, medical history and TC levels was collected at the baseline interview, as well as information on newly-diagnosed primary liver cancer cases during the follow-up period. A total of 110 612 males were recruited in the cohort by 31 December 2015. TC levels were divided into four categories by quartile (<4.27, 4.27-4.90, 4.90-5.56 and ≥5.56 mmol/L), with the first quartile group serving as the referent category. Cox proportional hazards regression model was used to evaluate the association between TC levels and primary liver cancer risk. Results: By December 31, 2015, a follow-up of 861 711.45 person-years was made with a median follow-up period of 8.83 years. During the follow-up, 355 primary liver cancer cases were identified. Compared with the first quartile, the HR of incident primary liver cancer among participants with the second, third and highest quartile TC levels were 0.76 (95%CI: 0.58-1.01), 0.59 (95%CI: 0.43-0.79), and 0.36 (95%CI: 0.25-0.52), respectively after adjusting for age, educational level, income level, smoking status, drinking status, body mass index, and HBsAg status (P_{for trend}<0.001). Subgroup analyses found that the association between TC levels and primary liver cancer was robust (all P_{for trend}<0.05). The results didn't change significantly after exclusion of newly-diagnosed cases within the first 2 years, males with history of cirrhosis or subjects who took antihyperlipidemic drugs, participants with higher TC levels had a lower risk of primary liver cancer (all P_{for trend}<0.05) and HR(95%CI) of incident primary liver cancer among participants with the highest quartile TC levels were 0.41 (0.28-0.61), 0.36 (0.25-0.53) and 0.38 (0.26-0.54), respectively. Conslusion: In this large prospective study, we found that baseline TC levels were inversely associated with primary liver cancer risk, and low TC level might increase the risk of primary liver cancer.

[The development and validation of risk prediction model for lung cancer: a systematic review]

Objective: To systematically understand the global research progress in the construction and validation of lung cancer risk prediction models. Methods: "lung neoplasms" , "lung cancer" , "lung carcinoma" , "lung tumor" , "risk" , "malignancy" , "carcinogenesis" , "prediction" , "assessment" , "model" , "tool" , "score" , "paradigm" , and "algorithm" were used as search keywords. Original articles were systematically searched from Chinese databases (CNKI, and Wanfang) and English databases (PubMed, Embase, Cochrane, and Web of Science) published prior to December 2018. The language of studies was restricted to Chinese and English. The inclusion criteria were human oriented studies with complete information for model development, validation and evaluation. The exclusion criteria were informal publications such as conference abstracts, Chinese dissertation papers, and research materials such as reviews, letters, and news reports. A total of 33 papers involving 27 models were included. The population characteristics of all included studies, study design, predicting factors and the performance of models were analyzed and compared. Results: Among 27 models, the number of American-based, European-based and Asian-based model studies was 12, 6 and 9, respectively. In addition, there were 6 Chinese-based model studies. According to the factors fitted into the models, these studies could be divided into traditional epidemiological models (11 studies), clinical index models (6 studies), and genetic index models (10 studies). 15 models were not validated after construction or were cross-validated only in the internal population, and the extrapolation effect of models was not effectively evaluated; 8 models were validated in single external population; only 4 models were verified in multiple external populations (3-7); the area under the curve (AUC) of models ranged from 0.57 to 0.90. Conclusion: Research on risk prediction models for lung cancer is in development stage. In addition to the lack of external validation of existing models, the exploration of potential clinical indicators was also limited.

[Progress in epidemiologic research of association between anthropometric indicators and risk for gastric cancer]

Gastric cancer is one of the most common cancer. Studies have been conducted to evaluate the association between anthropometric indicators and gastric cancer, but the results were inconsistent. Therefore, a literature retrieval was conducted by using PubMed and Wanfang databases to summarize the latest research progress in the cohort study of the association between anthropometric indicators and the risk for gastric cancer. It was found that both general obesity and abdominal obesity might increase the risk for gastric cancer, while the association between underweight and gastric cancer needs further study. This paper summarizes the progress in the cohort study of association between anthropometric indicators for the risk for gastric cancer in order to provide evidence for the prevention and control of gastric cancer.

[Progress in construction and verification of colorectal cancer risk prediction models: a systematic review]

Objective: To systematically review available risk prediction models evidence on construction and verification of colorectal cancer risk prediction models. Methods: "Colorectal neoplasms", "risk assessment", "colorectal cancer", "colorectal tumor", "colon cancer", "colon tumor", "rectal cancer", "rectal tumor", "anal cancer", "anal tumor", "risk prediction", "malignancy", "carcinogenesis", "model" were used as search keywords. Journal papers and grey literature were searched from Chinese electronic databases (CNKI and Wanfang) and English electronic databases (PubMed and Embase) from their inception to 30 Apr 2018. The language of literature was restricted to Chinese and English. The inclusion criteria were human-oriented researches with complete information for model construction,verification and evaluation. The exclusion criteria were informal publications such as conference abstracts, Chinese disertation papers, and non-primary research materials such as reviews,letters,and news reports. Descriptive characteristics,targeted population, study design, model construction method and prediction results were extracted. A total of 36 papers involving 27 models were included. The population characteristics of all included studies,the type of research, the method of model construction and the prediction results of the model were analyzed. Results: As for model construction,there were 13 European and American population based model studies,14 Asian population based model studies,including 7 Chinese mainland based model studies. According to the factors selected into the model, these models can be divided into traditional epidemiological models (17 models), clinical index combined models (4 models),and genetic susceptibility index combined models (6 models). As for model verification,only 9 models were cross-verified in the internal population after model construction, and the extrapolation of model prediction effect was not effectively evaluated; 17 models were verified in an external population; there was only one model verified in two external populations in terms of risk prediction effect; the area under the curve of 27 models was 0.56-0.85. Conclusion: The risk prediction model of colorectal cancer is in the development stage. The external evaluation of model prediction effect is less and the prediction ability is not good, and the existing models have limited exploration of clinical indicators.

[The relationship between inflammatory markers and the risk of lung cancer: a prospective cohort study]

Objective: To investigate whether elevated levels of C-reactive protein (CRP) and neutrophil (NE) in the blood is associated with an increased risk of lung cancer incidence. Methods: From 2006 to 2007, all employees and retirees from Kailuan (Group) Limited liability Corporation were included in this Kailuan Cohort study. The last follow-up date was December 2015. Data on new cases of lung cancer were collected, and multivariable Cox proportional hazards regression models were used to the relationship between baseline CRP and NE at baseline and risk of lung cancer. Results: A total of 92 735 participants were enrolled in this study. During the follow-up, 850 new cases of lung cancer were identified. All subjects were divided into four groups according to the combination level of CRP and NE at baseline: CRP≤3 mg/L and NE≤4×10(9)/L(Group A), CRP≤3 mg/L and NE>4×10(9)/L(Group B), CRP>3 mg/L and NE≤4×10(9)/L(Group C), CRP>3 mg/L and NE>4×10(9)/L(Group D). The cumulative incidence of lung cancer were 950/100 000, 1 030/100 000, 1 081/100 000 and 1 596/100 000 in these four groups, respectively (P<0.001). Multivariate Cox proportional risk model showed that participants from Group D had an significantly increased 72% risks of lung cancer when compared to Group A (95% CI: 1.40~2.12, P<0.001). Stratified analyses gender showed that males in Group D had higher risk of lung cancer when compared with participants in Group A (HR=1.73, 95% CI: 1.40~2.15, P<0.001). Conclusion: Elevated levels of CRP and NE might increase the risk of lung cancer.

[Systematic review of the methodology quality and reporting quality in colorectal cancer screening guidelines]

Objective: To systematically review the quality and reporting quality of colorectal cancer screening guidelines, and to provide reference for the update of colorectal cancer screening guidelines and colorectal cancer screening in China. Methods: "Colorectal cancer", "colorectal tumor", "screening", "screening", "guide", "consensus", "Colorectal cancer", "Colorectal neoplasms", "Screening", "Early Detection of Cancer", "Guideline" and "recommendation" were used as search keywords. The literature retrieval for all the Chinese and English guidelines published before April 2018 was conducted by using PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Data, China Biology Medicine disc (CBMdisc), Cochrane Library, Guideline International Network, China Guidelines Clearinghouse (CGC) and the official website of the US Preventive Services Task Force (USPSTF), the American Cancer Society (ACS), International Agency for Research on Cancer (IARC), Australia Cancer Council (ACC) and Association of Coloproctology of Great Britain & Ireland (ACPGBI). The inclusion criteria were independent guidance documents for colorectal cancer screening. The language is limited to Chinese and English. The exclusion criteria were literature on interpretation, evaluation, introduction, etc., as well as the translated version of the guide and old guides. The quality and reporting norms of colorectal cancer screening guidelines were compared and evaluated using the European Guideline Research and Assessment Tool (AGREE Ⅱ) and the Practice Guideline Reporting Standard (RIGHT). Results: A total of 15 guides were included. The results of the AGREE Ⅱ quality evaluation showed that the overall quality of 15 guides was high. Among them, there were 9 guides with an overall score of 50 or more, 10 with a recommendation level of "A", and 2 with a rating of "B". There were 3 guides for "C"; each guide scores higher in scope and purpose, and clarity, and scores vary greatly in the areas of participants, rigor, applicability, and independence. The results of the RIGHT evaluation showed that 15 guides were insufficient in six areas except for background information, evidence, recommendations, reviews and quality assurance, funding and conflict of interest statements and management, and other aspects. Conclusion: The overall quality of included guidelines for colorectal cancer screening is high, but the normative nature needs to be strengthened.

[Association between total cholesterol and risk of lung cancer incidence in men: a prospective cohort study]

Objective: To assess the association and intensity of baseline TC level with the incidence of lung cancer in men in China. Methods: Since May 2006, all the male workers, including the employees and the retirees in Kailuan Group were recruited in the Kailuan male dynamic cohort study. Information about demographics, medical history, anthropometry and TC level were collected at the baseline interview, as well as the information of newly-diagnosed lung cancer cases during the follow-up period. According to guidelines for blood lipids in Chinese adults and the distribution in the population, TC level was classified into five groups as followed: <160, 160-, 180-, 200- and ≥240 mg/dl, with the second quintile group (160- mg/dl) serving as the referent category. Cox proportional hazards regression model and restricted cubic spline (RCS) model were used to evaluate the association and the nonlinear association between baseline TC level and the risk of lung cancer in the men. Results: By December 31, 2014, for the 109 884 men, a follow up of 763 819.25 person-years was made with a median follow-up period of 7.88 years. During the follow up, 808 lung cancer cases were identified. After adjustment for age, education level, income level, smoking status, alcohol consumption level, history of dust exposure, FPG level and BMI, HR (95%CI) of lung cancer for men with lower TC level (<160 mg/dl) and higher TC level (≥240 mg/dl) were 1.34 (1.04- 1.72) and 1.45 (1.09-1.92), respectively, compared with men with normal TC level (160- mg/dl). The results didn't change significantly after exclusion of newly diagnosed cancer cases within 2 years of follow up and subjects with the history of hyperlipidemia. Conclusion: Our results showed that TC might be associated with higher risk of lung cancer. Men with lower TC level or higher TC level had higher risk for lung cancer. Keep moderate TC level might be one of the effective precaution for the prevention of lung cancer.

[Alcohol consumption and the risk of lung cancer in males: a prospective cohort study]

Objective: To investigate the association between alcohol consumption and lung cancer risk in Chinese males. Methods: Information on alcohol consumption and outcomes were collected on a biennial basis among males in Kailuan Cohort (2006-2015). In addition, electronic databases of hospitals affiliated to Kailuan Community, Insurance Systems of Kailuan Community and Tangshan were also used for supplementary information retrieval. Cox proportional hazards regression models were used to evaluate the hazard ratio (HR) and 95%CI of baseline frequency and type of alcohol consumption associated with lung cancer risk in males. Non-drinkers were used as control group. Results: A total of 101 751 males were included and 913 new lung cancer cases were identified in the Kailuan male cohort study, with a total follow-up time of 808 146.56 person-years and a median follow-up time of 8.88 years by 31 December 2015. After adjusting for potential confounding factors, the HR of former drinkers, occasional drinkers (<1/day) and drinkers (≥1/day) were 1.30 (95%CI: 0.90-1.88), 0.80 (95%CI: 0.64-1.01) and 1.04 (95%CI: 0.85-1.27), respectively, compared with non-drinkers. In addition, drinking beer/red wine (HR=0.91, 95%CI: 0.69-1.20) and white wine (HR=0.99, 95%CI: 0.83-1.19) showed no significant association with lung cancer. The results were similar when stratified analysis were conducted. Conclusion: Our study results don't support the hypothesis that alcohol consumption is significantly associated with the risk of lung cancer in males.

[Relation between waist circumference and risk of male lung cancer incidence: a prospective cohort study]

Objective: To investigate the association between waist circumference and risk of male lung cancer incidence. Methods: Since May 1, 2006, all the male employees including the retirees in Kailuan Group had been recruited into a Chinese Kailuan Male Cohort study. Information on anthropometries including body weight, height and waist circumference were collected at the baseline investigation, as well as information on newly-diagnosed lung cancer cases during the follow-up period. Waist circumference was grouped by quintiles of the population waist circumference distribution and categorized into the following five groups: <80, 80-, 85-, 90- and ≥95 cm, with the relevant normal group, the second quintile group (80-cm), serving as the referent category. Multivariable Cox proportional hazards regression models were used to evaluate the association between levels of waist circumference and risk of lung cancer. Results: A total of 105 386 males were recruited in the study, with 739 651.13 person-years of follow-up and an average follow-up period of 7.00 years. By the end of 2014, a total of 707 lung cancer cases were identified in the cohort study. Compared with males having the 80-cm of waist circumference, the hazard ratio (HR) and 95% confidence intervals (CI) of lung cancer were 1.17(0.90-1.52), 0.96(0.74-1.23), 0.94(0.72-1.21) and 0.80(0.63-1.03) for the <80, 85-, 90- and ≥95 cm of waist circumference, after adjustment for potential confounding factors including age, education level, smoking status and pack-year amount, alcohol consumption, physical activities, environment for working place and the prevalence on diabetes. The inverse association existed in smokers (≥95 cm compared to 80-cm of waist circumference: HR=0.69, 95%CI: 0.48-0.99) and alcohol drinkers (≥95 cm compared to 80-cm of waist circumference: HR=0.65, 95%CI: 0.45-0.94) when analysis was conducted in subgroups stratified by smoking or alcohol drinking status. Conclusion: Waist circumference might be inversely associated with male lung cancer risk.

[A prospective follow-up study on the association between serum level of C-reactive protein and risk of digestive system cancers in Chinese women]

Objective: It has been reported by some prospective studies that C-reactive protein (CRP) is associated with cancer risk. However, the correlation between CRP and digestive system cancers has not been evaluated in Chinese females. We conducted a large population-based cohort study to investigate whether elevated level of CRP in serum is associated with an increased risk of digestive system cancers in Chinese women. Methods: From the Chinese Kailuan Female Cohort, 19, 437 women were enrolled in this study in July 2006, and all of the subjects were followed up through 2014. At the baseline investigation, the serum levels of high-sensitivity CRP (hsCRP) were tested for all subjects, and demographic information and risk factor data were collected. Multivariable Cox proportional hazards regression model was used to calculate the hazard ratios (HR) and 95% confidence intervals (95% CI) for the baseline levels of hsCRP after adjusting for age, marital status, smoking, drinking, body mass index (BMI), diabetes and physical activity, and risk of digestive system tumors (including colorectal cancer, stomach cancer, pancreas cancer, liver and gallbladder cancer, and other cancers). Results: By Dec 31, 2014, a total of 100 incident cancer cases were observed, including 47 colorectal cancers, 17 stomach cancers, and altogether 29 pancreas, liver and gallbladder cancers. All the subjects investigated were divided into three groups according to the level of hsCRP (<1 mg/L, 1-3 mg/L and >3 mg/L). The 8-year cumulative incidence of digestive system cancers were 405/100 000, 520/100 000 and 787/100 000 in these 3 groups, respectively (Log rank test χ² = 8.37, P=0.015). Compared to those with lower hsCRP levels (<1 mg/L), the women with higher hsCRP (>3 mg/L) had a significantly increased risk of pancreas, liver and gallbladder cancers (HR = 2.70, 95% CI = 1.06-6.91; P_trend = 0.036). Conclusions: Elevated levels of hsCRP at baseline may be associated with increased risk of certain digestive system cancers.

[Association between body mass index and risk of lung cancer in non-smoking males: a prospective cohort study]

Objective: To assess the association between baseline body mass index (BMI) and risk of lung cancer in non-smoking males. Methods: A dynamic non-smoking male cohort was established on May, 2006. Baseline information on demography, lifestyle, such as smoking status and alcohol consumption, anthropometry, such as body height and weight, were collected during the baseline interview, and the information of newly-diagnosed lung cancer cases were also collected during the follow-up period. Multivariable Cox proportional-hazards regression model was used to analyze the association between baseline BMI and lung cancer in non-smoking males. Results: By December 31, 2011, a total of 48 799 male non-smokers had been assessed in the study and there were 214 620.18 person-years of follow-up and 4.40 years of average follow-up period. During follow-up, 198 lung cancer cases were identified among the 48 799 non-smoking males. Compared with those with normal BMI (kg/m²) (18.5≤BMI<24.0), the hazard ratio (95%CI) of lung cancer were 1.14(0.53-2.45), 0.57(0.41-0.78) and 0.61(0.38-0.97) for underweight (BMI<18.5), overweight (24.0≤BMI<28.0) and obese males (≥28.0), respectively, after adjustment for potential confounding factors, including age, education level, alcohol consumption, physical activity, history of diabetes and work environment. Baseline BMI was negatively associated with the risk of lung cancer in non-smoking males and the risk would be reduced by 22% (HR=0.78, 95% CI: 0.64-0.95) for per 5 kg/m² BMI increase. The negative association between BMI and risk of lung cancer was significant among non-smoking males who aged ≥50 years, and in those who had physical exercise <4 times/week, never drunk and worked above the coal mine, and for per 5 kg/m² BMI increase, the risk of lung cancer would be reduced by 26%(HR=0.74, 95%CI: 0.60-0.92), 24%(HR=0.76, 95%CI: 0.62-0.95), 20% (HR=0.80, 95%CI: 0.65-1.00) and 23% (HR=0.77, 95%CI: 0.61-0.97), respectively. The result was similar after excluding the cancer patients newly diagnose within 1-year and their contribution person years. Conclusion: Baseline BMI might be negatively associated with risk of lung cancer in non-smoking males.

[Body mass index and the risk of lung cancer incidence in smokers: a prospective cohort study]

OBJECTIVE

To investigate the effect of baseline body mass index (BMI) on the risk of lung cancer incidence in male smokers.

METHODS

All the male employees and retirees of the Kailuan Group were recruited in the Chinese Kailuan Male Cohort Study, and they had been experienced routine physical examinations every two years since May, 2006. Up to 31st December 2011, a total of 3 rounds physical examinations had been completed. A total of 42 718 male smokers candidates from the Chinese Kailuan Male Cohort Study were enrolled in the present study. The date of entering this study was defined as that of taking first check-up, and the date of end-of-observation was defined as that of cancer diagnosis, death or end of follow-up (31 December 2011). Information on demographics, lifestyle such as smoking, alcohol consumption, anthropometries such as height and weight, as well as the information of newly-diagnosed cancer cases, were collected at the baseline investigation. Multivariable Cox proportional hazards regression models were used to investigate the association between levels of the baseline BMI and risk of lung cancer.

RESULTS

Of the 42 718 male smokers, there were 181 998.09 person-years of follow-up, taking 4.26 years of average follow-up period. During follow-up, 234 new lung cancer cases were identified among the 42 718 male smokers and the crude incidence density was 128.57/100 000. After the factors adjustment for age, education level, alcohol consumption, physical activity, work environment and cumulative smoking levels (pack-years), compared with subjects of normal BMI group, hazard ratio and 95% confidence intervals of lung cancer for subjects of underweight, overweight, and obesity were 1.63 (0.79-3.37), 0.79 (0.57-1.09) and 0.50 (0.27-0.91), respectively. After the facotors adjustment for age, education level, alcohol consumption, physical activity, work environment and cumulative smoking levels (pack-years), compared with subjects of normal BMI, hazard ratio and 95% confidence intervals of lung cancer for subjects of obesity among subjects who aged 50 years or above, smoked more than 20 pack-years, and exercised less than 4 times per week were 0.33 (0.15-0.71), 0.27 (0.10-0.75), and 0.44 (0.20-0.96), respectively. Obesity subjects who worked above the well had decreased risk of lung cancer (HR=0.38, 95% CI: 0.15-0.96) compared with normal BMI ones who worked above the well.

CONCLUSION

BMI was negatively correlated with the risk of lung cancer in male smokers. As for male smokers, one of the most effective approaches to prevent and control the lung cancer has been shown to quit smoking and keep fit.