Effects of intensity-modulated radiotherapy combined with chemotherapy and prognostic factors in patients with locally advanced oesophageal cancer.

PURPOSE: We explored the efficacy and influencing factors of chemoradiotherapy and radiotherapy alone in patients with locally advanced oesophageal squamous cell carcinoma. METHODS: We retrospectively analysed 226 locally advanced oesophageal squamous cell carcinoma patients who underwent chemoradiotherapy and radiotherapy alone. Univariate and multivariate Cox regression analyses were used to analyse the impact of relevant factors. The endpoint was overall survival and progression-free survival. RESULTS: Compared with the radiotherapy group, the chemoradiotherapy group had a significant difference in the overall survival rate and the progression-free survival rate between 3 and 5 years (both p â€‹< â€‹0.05). The incidences of radiation pneumonitis and radiation oesophagitis were analysed, and the differences were not significant (all p â€‹> â€‹0.05). The incidence of haematological toxicity in the chemoradiotherapy group was significantly higher than that in the radiotherapy group (p â€‹= â€‹0.001). There was a significant difference in the incidence of haematological toxicity between the ≤65 and the >65 age groups (p â€‹< â€‹0.05). Tumour location, T stage, tumour length, tumour target volume, and short-term curative effect were the main factors affecting the prognosis (all p â€‹< â€‹0.05). T stage, gross tumour volume, and short-term curative effect were all independent factors affecting the prognosis (all p â€‹< â€‹0.05). CONCLUSIONS: Patients with locally advanced oesophageal cancer who received intensity-modulated radiotherapy (IMRT) combined with chemotherapy had significant survival benefits compared with radiotherapy alone. Haematological toxicity was the main adverse reaction. T-stage, gross tumour volume and short-term curative effect were independent factors influencing the prognosis.

Analyzing lung cancer risks in patients with impaired pulmonary function through characterization of gut microbiome and metabolites.

BACKGROUND: Lung cancer (LC) is one of the most devastating diseases worldwide, there is growing studies confirm the role of impaired lung function in LC susceptibility. Moreover, gut microbiota dysbiosis is associated with LC severity. Whether alterations in gut microbiota and metabolites are associated with long-term lung dysfunction in LC patients remain unclear. Our study aimed to analyze the risk factors in LC patients with impaired pulmonary function based on the characteristics of the gut microbiome and metabolites. METHODS: Fecal samples from 55 LC patients and 28 benign pulmonary nodules patients were collected. Pulmonary ventilation function was graded according to the American Thoracic Society/ European Respiratory Society (ATS/ERS) method. LC patients were divided into 3 groups, including 20 patients with normal lung ventilation, 23 patients with mild pulmonary ventilation dysfunction and 12 patients with moderate or above pulmonary ventilation dysfunction. The fecal samples were analyzed using 16 S rRNA gene amplicon sequencing and metabolomics. RESULTS: The gut microbiome composition between LC patients and benign pulmonary nodules patients presented clearly differences based on Partial Least Squares Discriminant Analysis (PLS-DA). Pulmonary ventilation function was positively correlated with LC tumor stage, the richness and diversity of the gut microbiota in LC patients with moderate or above pulmonary ventilation dysfunction increased significantly, characterized by increased abundance of Subdoligranulum and Romboutsia. The metabolomics analysis revealed 69 differential metabolites, which were mainly enriched in beta-Alanine metabolism, styrene degradation and pyrimidine metabolism pathway. The area under the curve (AUC) combining the gut microbiome and metabolites was 90% (95% CI: 79-100%), indicating that the two species and four metabolites might regarded as biomarkers to assess the prediction of LC patients with impaired pulmonary function. CONCLUSIONS: Our results showed that microbiome and metabolomics analyses provide important candidate to be used as clinically diagnostic biomarkers and therapeutic targets related to lung cancer with impaired pulmonary function.

Characterizing microbiota and metabolomics analysis to identify candidate biomarkers in lung cancer.

Background: Lung cancer is the leading malignant disease and cause of cancer-related death worldwide. Most patients with lung cancer had insignificant early symptoms so that most of them were diagnosed at an advanced stage. In addition to factors such as smoking, pollution, lung microbiome and its metabolites play vital roles in the development of lung cancer. However, the interaction between lung microbiota and carcinogenesis is lack of systematically characterized and controversial. Therefore, the purpose of this study was to excavate the features of the lung microbiota and metabolites in patients and verify potential biomarkers for lung cancer diagnosis. Methods: Lung tissue flushing solutions and bronchoalveolar lavage fluid samples came from patients with lung cancer and non-lung cancer. The composition and variations of the microbiota and metabolites in samples were explored using muti-omics technologies including 16S rRNA amplicon sequencing, metagenomics and metabolomics. Results: The metabolomics analysis indicated that 40 different metabolites, such as 9,10-DHOME, sphingosine, and cysteinyl-valine, were statistically significant between two groups (VIP > 1 and P < 0.05). These metabolites were significantly enriched into 11 signal pathways including sphingolipid, autophagy and apoptosis signaling pathway (P < 0.05). The analysis of lung microbiota showed that significant changes reflected the decrease of microbial diversity, changes of distribution of microbial taxa, and variability of the correlation networks of lung microbiota in lung cancer patients. In particular, we found that oral commensal microbiota and multiple probiotics might be connected with the occurrence and progression of lung cancer. Moreover, our study found 3 metabolites and 9 species with significantly differences, which might be regarded as the potential clinical diagnostic markers associated with lung cancer. Conclusions: Lung microbiota and metabolites might play important roles in the pathogenesis of lung cancer, and the altered metabolites and microbiota might have the potential to be clinical diagnostic markers and therapeutic targets associated with lung cancer.

Prognostic Factors for Cardiovascular Events in Elderly Patients with Community Acquired Pneumonia: Results from the CAP-China Network.

Background: Limited data were available about the burden of cardiovascular events (CVEs) during hospitalization in elderly patients with community-acquired pneumonia (CAP). The aim was to assess the incidence, characteristics, predictive factors and outcomes of CVEs in elderly patients with CAP during hospitalization. Methods: This study was a multicenter, retrospective research on hospitalized elderly patients with CAP from the CAP-China network. Predictive factors for the occurrence of CVEs and 30-day mortality were identified by multivariable logistic regression analysis. Results: Of 2941 hospitalized elderly patients, 402 (13.7%) developed CVEs during hospitalization with the median age of 81 years old. Compared with non-CVEs patients, patients with CVEs were older, more comorbidities, and higher disease severity; use of glucocorticoids, leukocytosis, azotemia, hyponatremia, multilobe infiltration and pleural effusion were more common; the rate of clinical failure (CF), in-hospital mortality and 30-day mortality were higher, which significantly increased with age and the number of CVEs (p < 0.001). Multivariable logistic regression showed previous history of congestive heart failure (odds ratio [OR], 6.16; 95% CI, 4.14-9.18), CF (OR, 4.69; 95% CI, 3.392-6.48), previous history of ischemic heart disease (OR, 2.22; 95% CI, 1.61-3.07), use of glucocorticoids (OR, 2.0; 95% CI, 1.39-2.89), aspiration (OR, 1.88; 95% CI, 1.26-2.81), pleural effusion (OR, 1.66; 95% CI, 1.25-2.20), multilobe infiltration (OR, 1.50; 95% CI, 1.15-1.96), age (OR, 1.05; 95% CI, 1.04-1.07), and blood urea nitrogen (OR, 1.03; 95% CI, 1.01-1.06) were independent predictors for the occurrence of CVEs, while level of blood sodium (OR, 0.98; 95% CI, 0.97-0.99) was protective factor. Renal failure (OR, 9.46; 95% CI, 4.17-21.48), respiratory failure (OR, 9.32; 95% CI, 5.91-14.71), sepsis/septic shock (OR, 7.87; 95% CI, 3.58-17.31), new cerebrovascular diseases (OR, 5.94; 95% CI, 1.78-19.87), new heart failure (OR, 4.04; 95% CI, 1.15-14.14), new arrhythmia (OR, 2.38; 95% CI, 1.11-5.14), aspiration (OR, 1.95; 95% CI, 1.09-3.50), CURB-65 (OR, 1.57; 95% CI, 1.21-2.02), and white blood cell count (OR, 1.05; 95% CI, 1.02-1.09) were independent predictors for 30-day mortality in elderly patients with CAP, while lymphocyte count (OR, 0.63; 95% CI, 0.46-0.87) was protective factor. Conclusion: Patients with CVEs had heavier disease burden and worse prognosis. Early recognition of risk factors is meaningful to strengthen the management in elderly patients with CAP.

Myelitis: A Common Complication of Tuberculous Meningitis Predicting Poor Outcome.

Background: Myelitis is an important complication in patients with tuberculous meningitis (TBM). However, a paucity of publications exists on the spectrum of neurological and MRI findings of TBM-related myelitis. The risk factors and prognosis of myelitis in patients with TBM are not fully understood. Therefore, this study aims to identify the risk factors, clinicoradiological features, and prognostic impact of myelitis for patients with TBM. Methods: We conducted a retrospective study in our institution. Patients with TBM who were consecutively admitted during the period of August 2015 to December 2019 were included. We reviewed the demographic characteristics, clinical, laboratory and MRI findings, and clinical outcomes of all of the included patients. The diagnosis of myelitis was identified by a hyperintensity on T2-weighted images that were associated with cord edema, enlargement, and marginal or no enhancement on contrast-enhanced images. Results: A total of 114 patients were included. Myelitis occurred in 19 (16.7%) patients, five of whom paradoxically developed myelitis. The common clinical signs of myelitis were paraparesis (738.9%), quadriparesis (844.4%), urinary retention or constipation (1,477.8%), and paresthesias in the lower limbs (1,052.6%). In the MRI findings, the hyperintensities on T2-weighted images involved more than 3 spinal cord segments. Myelitis was often combined with other forms of spinal cord injury, including 10 patients (52.6%) with spinal meningeal enhancement, 7 patients (36.8%) with enlargement of the central canal of the spinal cord, 6 patients (31.6%) with tuberculoma, and 4 patients (21.1%) with arachnoiditis and 1 patient (5.3%) with cerebrospinal fluid (CSF) loculations. None of the 5 patients with paradoxical myelitis were complicated with spinal meningeal enhancement and arachnoiditis, while 4 patients were complicated with enlargements of the central canal of the spinal cord. In multivariable analysis, a grade III disease severity on admission [p = 0.003, odds ratio (OR) = 8.131, 95% CI: 2.080-31.779] and high CSF protein (p = 0.033, OR = 1.698, 95% CI: 1.043-2.763) were independent risk factors for myelitis. After the 6 months follow-up, myelitis (p = 0.030, OR = 13.297, 95% CI: 1.283-137.812) and disturbance of consciousness (p = 0.042, OR = 12.625, 95% CI: 1.092-145.903) were independent risk factors for poor outcomes. Conclusion: Myelitis was a common complication of TBM and independently predicted a poor outcome. A grade III disease severity and high CSF protein on admission were independent risk factors for myelitis. Paradoxical myelitis was rarely complicated with spinal meningeal enhancements and arachnoiditis, indicating that the immune reaction may play a dominant role.

Concurrent pigeon paramyxovirus-1 and Acinetobacter baumannii infection in a fatal case of pneumonia.

Pigeon paramyxovirus type 1 (PPMV-1), an antigenic variant of avian paramyxovirus type 1 (APMV-1), mainly infects pigeons. PPMV-1 genotype VI is the dominant genotype infecting pigeons in China. Human infection of avian paramyxovirus was rarely reported, and usually developed mild symptoms, such as conjunctivitis. We detected PPMV-1 in the lower respiratory sample from a fatal case with severe pneumonia; this patient aged 64 years presented cough, fever, and haemoptysis for 8 days and was admitted to hospital on Dec 26, 2020. He developed acute respiratory distress syndrome and sepsis in the following days and died of multiple organ failure on Jan 7, 2021. Sputum and blood culture reported multidrug-resistant Acinetobacter baumannii (ABA) for samples collected on days 22 and 19 post-illness, respectively. However, clinical metagenomic sequencing further reported PPMV-1 besides ABA in the bronchoalveolar lavage fluid. The PPMV-1 genome showed 99.21% identity with a Chinese strain and belonged to VI genotype by BLAST analysis. Multiple basic amino acids were observed at the cleavage site of F protein (113RKKRF117), which indicated high virulence of this PPMV-1 strain to poultry. The patient had close contact with pigeons before his illness, and PPMV-1 nucleic acid was detected from the pigeon feather. PPMV antibody was also detected in the patient serum 20 days after illness. In conclusion, concurrent PPMV-1 genotype VI.2.1.1.2.2 and ABA infection were identified in a fatal pneumonia case, and cross-species transmission of PPMV-1 may occur between infected pigeons and the human being.

Sirolimus combined with oseltamivir and corticosteroid treatment for a puerpera with severe pneumonia caused by 2009 pandemic H1N1: A case report.

Severe pneumonia in patients infected with the 2009 pandemic H1N1 (pH1N1) virus was partially attributed to excessive immune response. Anti-virus treatment for these patients was insufficient. Here we reported the therapy effect of sirolimus, an immunosuppressor, combined with oseltamivir and corticosteroid for a puerpera with severe pneumonia caused by pH1N1 virus. This patient has infected with the pH1N1 virus in late pregnancy, and antiviral therapy was not implemented timely. She developed severe pneumonia and ARDS rapidly and need receive a cesarean section on the 39th week after pregnancy. After giving birth to a healthy baby, she received a combination of oseltamivir, sirolimus and corticosteroid, and improved in the following days. Moreover, the cytokines in serum and viral loads in BALF decreased significantly. She recovered without infectious symptoms and was discharged. Sirolimus combined with oseltamivir and corticosteroid is likely responsible for lowering the viral loads, reducing the patient's cytokine level, and further improving her clinical outcomes. It provides evidence that adjuvant treatment was beneficial to patients with severe pneumonia induced by the pH1N1 virus.

Cost Effectiveness of Different Initial Antimicrobial Regimens for Elderly Community-Acquired Pneumonia Patients in General Ward.

PURPOSE: The cost-effectiveness of different guideline-concordant antimicrobial regimens for elderly patients with community-acquired pneumonia (CAP) was rarely discussed. This study attempts to explore the most appropriate cost-effectiveness of guideline-concordant antimicrobial regimen for elderly patients with CAP in general wards. PATIENTS AND METHODS: This was a multicenter, retrospective, 4:2:1 matched study enrolling 511 elderly patients with CAP hospitalized in general wards. Two hundred ninety-two patients prescribed with ß-lactam monotherapy (group A), 146 patients prescribed with fluoroquinolone monotherapy (group B) and 73 patients prescribed with ß-lactam/macrolide combination therapy (group C). Clinical outcomes and medical costs were analyzed by χ 2 test for categorical variables or Kruskal-Wallis H-test for continuous variables. RESULTS: There were no statistical differences in imaging features, etiology and complications during hospitalization among these three groups. The rates of clinical failure occurrence, in-hospital mortality, 30-day mortality and 60-day mortality also had no significant differences among group A, B and C patients; however, the median length of stay (LOS) in group A patients was 12.0 days, which was significantly higher than that in group B and C patients (both 10.0 days, p<0.02). The median total, drug, and antibiotic costs for one elderly CAP episode in group B patients were RMB 10368.4, RMB 3874.8, and RMB 1796.3, respectively, which were significantly lower than those in group A and C patients (p<0.01). CONCLUSION: Non-inferiority of clinical failure occurrence and short-term mortality was observed in different guideline-concordant antimicrobial regimens for elderly patients with CAP in general wards; however, the median LOS and hospitalization-associated costs for one elderly CAP episode with fluoroquinolone monotherapy were significantly lowest, and this strategy was considered to be the most cost-effective strategy in general wards.

Pulmonary benign metastasizing leiomyoma: a case report and literature review.

Benign metastasizing leiomyoma (BML) is a rare condition that occurs mainly in premenopausal women and is characterized most commonly by pulmonary metastases. Here, we report the case of a 45-year-old woman who presented with multiple bilateral pulmonary nodules on chest examination during a health checkup 13 years after myomectomy. This patient has a normal menstrual cycle, moderate anemia, and no obvious respiratory symptoms. Serum concentrations of cancer markers such as carcinoembryonic antigen, neuron specific enolase, cytokeratin 19 fragments, and pro-gastrin-releasing peptide were within normal limits. Color doppler ultrasound was also performed, several hypoechoic regions were found in uterine bodies and cavity. The computed tomography (CT)-guided lung biopsy was used for histopathological examination. Immunohistochemical staining revealed BML which were positive for smooth muscle antibody, desmin, vimentin, estrogen and progesterone receptors, and Ki-67 positive rate of about 1%. Hysterectomy and bilateral adnexectomy were performed as a part of treatment. The lung nodules were meticulously monitored at follow-up. Three months later, the repeat CT scan showed that the nodules had reduced in size, and no new nodules had appeared, 1 year later, CT scan showed no obvious changes in lung nodules. This study is of great significance as the results will be helpful in diagnosing and treating future pulmonary benign metastasizing leiomyoma (PBML) cases.

Disease burden and prognostic factors for clinical failure in elderly community acquired pneumonia patients.

BACKGROUND: The study was to evaluate initial antimicrobial regimen and clinical outcomes and to explore risk factors for clinical failure (CF) in elderly patients with community-acquired pneumonia (CAP). METHODS: 3011 hospitalized elderly patients were enrolled from 13 national teaching hospitals between January 1, 2014 and December 31, 2014 initiated by the CAP-China network. Risk factors for CF were screened by multivariable logistic regression analysis. RESULTS: The incidence of CF in elderly CAP patients was 13.1%. CF patients were older, longer hospital stays and higher treatment costs than clinical success (CS) patients. The CF patients were more prone to present hyperglycemia, hyponatremia, hypoproteinemia, pleural effusion, respiratory failure and cardiovascular events. Inappropriate initial antimicrobial regimens in CF group were significantly higher than CS group. Undertreatment, CURB-65, PH < 7.3, PaO2/FiO2 < 200 mmHg, sodium < 130 mmol/L, healthcare-associated pneumonia, white blood cells > 10,000/mm3, pleural effusion and congestive heart failure were independent risk factors for CF in multivariable logistic regression analysis. Male and bronchiectasis were protective factors. CONCLUSIONS: Discordant therapy was a cause of CF. Early accurate detection and management of prevention to potential causes is likely to improve clinical outcomes in elderly patients CAP. TRIAL REGISTRATION: A Retrospective Study on Hospitalized Patients With Community-acquired Pneumonia in China (CAP-China) (RSCAP-China), NCT02489578. Registered 16 March 2015, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0005E5S&selectaction=Edit&uid=U0000GWC&ts=2&cx=1bnotb.

Effects of age, comorbidity and adherence to current antimicrobial guidelines on mortality in hospitalized elderly patients with community-acquired pneumonia.

BACKGROUND: Limited information exists on the clinical characteristics predictive of mortality in patients aged ≥65 years in many countries. The impact of adherence to current antimicrobial guidelines on the mortality of hospitalized elderly patients with community-acquired pneumonia (CAP) has never been assessed. METHODS: A total of 3131 patients aged ≥65 years were enrolled from a multi-center, retrospective, observational study initiated by the CAP-China network. Risk factors for death were screened with multivariable logistic regression analysis, with emphasis on the evaluation of age, comorbidities and antimicrobial treatment regimen with regard to the current Chinese CAP guidelines. RESULTS: The mean age of the study population was 77.4 ± 7.4 years. Overall in-hospital and 60-day mortality were 5.7% and 7.6%, respectively; these rates were three-fold higher in those aged ≥85 years than in the 65-74 group (11.9% versus 3.2% for in-hospital mortality and 14.1% versus 4.7% for 60-day mortality, respectively). The mortality was significantly higher among patients with comorbidities compared with those who were otherwise healthy. According to the 2016 Chinese CAP guidelines, 62.1% of patients (1907/3073) received non-adherent treatment. For general-ward patients without risk factors for Pseudomonas aeruginosa (PA) infection (n = 2258), 52.3% (1094/2090) were over-treated, characterized by monotherapy with an anti-pseudomonal ß-lactam or combination with fluoroquinolone + ß-lactam; while 71.4% of intensive care unit (ICU) patients (120/168) were undertreated, without coverage of atypical bacteria. Among patients with risk factors for PA infection (n = 815), 22.9% (165/722) of those in the general ward and 74.2% of those in the ICU (69/93) were undertreated, using regimens without anti-pseudomonal activity. The independent predictors of 60-day mortality were age, long-term bedridden status, congestive heart failure, CURB-65, glucose, heart rate, arterial oxygen saturation (SaO2) and albumin levels. CONCLUSIONS: Overtreatment in general-ward patients and undertreatment in ICU patients were critical problems. Compliance with Chinese guidelines will require fundamental changes in standard-of-care treatment patterns. The data included herein may facilitate early identification of patients at increased risk of mortality. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov ( NCT02489578 ).

Disease characteristics and management of hospitalised adolescents and adults with community-acquired pneumonia in China: a retrospective multicentre survey.

OBJECTIVES: To describe the clinical characteristics and management of patients hospitalised with community-acquired pneumonia (CAP) in China. DESIGN: This was a multicentre, retrospective, observational study. SETTING: 13 teaching hospitals in northern, central and southern China from 1 January 2014 to 31 December 2014 PARTICIPANTS: Information on hospitalised patients aged ≥14 years with radiographically confirmed pneumonia with illness onset in the community was collected using standard case report forms. PRIMARY AND SECONDARY OUTCOME MEASURES: Resource use for CAP management. RESULTS: Of 14 793 patients screened, 5828 with radiographically confirmed CAP were included in the final analysis. Low mortality risk patients with a CURB-65 score 0-1 and Pneumonia Severity Index risk class I-II accounted for 81.2% (4434/5594) and 56.4% (2034/3609) patients, respectively. 21.7% (1111/5130) patients had already achieved clinical stability on admission. A definite or probable pathogen was identified only in 12.7% (738/5828) patients. 40.9% (1575/3852) patients without pseudomonal infection risk factors received antimicrobial overtreatment regimens. The median duration between clinical stability to discharge was 5.0 days with 30-day mortality of 4.2%. CONCLUSIONS: These data demonstrated the overuse of health resources in CAP management, indicating that there is potential for improvement and substantial savings to healthcare systems in China. TRIAL REGISTRATION NUMBER: NCT02489578; Results.

CYP1A1 Ile462Val polymorphism contributes to lung cancer susceptibility among lung squamous carcinoma and smokers: a meta-analysis.

Many studies have examined the association between the CYP1A1 Ile462Val gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. Ultimately, 43 case-control studies, comprising 19,228 subjects were included. A significantly elevated lung cancer risk was associated with 2 Ile462Val genotype variants (for Val/Val vs Ile/Ile: OR = 1.22, 95% CI = 1.08-1.40; for (Ile/Val +Val/Val) vs Ile/Ile: OR = 1.15, 95% CI = 1.07-1.23) in overall population. In the stratified analysis, a significant association was found in Asians, Caucasians and lung SCC, not lung AC and lung SCLC. Additionally, a significant association was found in smoker population and not found in non-smoker populations. This meta-analysis suggests that the Ile462Val polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility in Asian and Caucasian populations and there is an interaction with smoking status, but these associations vary in different histological types of lung caner.

CYP1A1 MspI polymorphisms and lung cancer risk: an updated meta-analysis involving 20,209 subjects.

Published data describing the association between CYP1A1 MspI gene polymorphism and lung cancer risk are inconclusive. To determine a more conclusive relationship, we performed an updated meta-analysis of all eligible studies and conducted the subgroup analysis by stratification according to the ethnicity source, histological types of lung cancer, gender and smoking status of case and control populations. A total of 51 studies comprising 20,209 subjects were included in the analysis. A significantly elevated lung cancer risk was associated with two variant genotypes (for TT vs CC: OR=1.24, 95% CI=1.11-1.40; for CT and TT combined vs CC: OR=1.19, 95% CI=1.12-1.27) in the overall population. In the stratified analysis, significantly higher risks associated with lung cancer were found in Asians, Caucasians, lung SCC, lung AC and the male population. In contrast, negligible risks were found in the mixed population, lung SCLC and the female population. Additionally, a significant association was found in the smoker population, whereas no association was found in non-smoker populations. This meta-analysis suggests that the MspI polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility, and that there is an interaction between the CYP1A1 polymorphism and smoking. However, the associations vary in different ethnic populations, histological types of lung cancer and the gender of case and control populations.

Chlamydia pneumoniae infection and lung cancer risk: a meta-analysis.

Chlamydia pneumoniae (C. pneumoniae) is a common cause of acute respiratory infection and has been hypothesised to cause several chronic diseases, including lung cancer. Numbers studies were conducted to analyse the association between C. pneumoniae infection and risk of lung cancer, but no clear consensus had been found. To assess this relationship more precisely, a meta-analysis was performed. The electronic databases PubMed, Embase, Web of Science and CNKI were searched; Data were extracted and analysed independently by two investigators. Ultimately, 12 studies, involving 2595 lung cancer cases and 2585 controls from four prospective studies and eight retrospective studies were included. Overall, people exposed to C. pneumoniae infection had an odds ratio (OR) of 1.48 (95% confidence interval (CI), 1.32-1.67) for lung cancer risk, relative to those not exposed. C. pneumoniae infection was clearly identified as a risk factor for lung cancer in both prospective studies (OR, 1.16; 95% CI, 1.00-1.36) and retrospective studies (OR, 2.17; 95% CI, 1.79-2.63) and in both IgA ≥ 16 cutoff group (OR, 1.22; 95% CI, 1.06-1.41) and the IgA ≥ 64 cutoff group (OR, 2.35; 95% CI, 1.88-2.93). In conclusion, C. pneumoniae infection is associated with an increased risk for lung cancer, higher titre may be a better predictor of lung cancer risk.