Occupational exposure to endotoxins and small cell lung cancer: a systematic review with meta-analysis.

The relationship of occupational exposure to endotoxins with different histologic subtypes of lung cancer has not been established. Our objective was to conduct a systematic review with meta-analysis to assess the effect of exposure to endotoxins on the development of small cell lung cancer (SCLC). A bibliographic search was conducted using MEDLINE, Embase, CENTRAL, and Web of Science databases until December 2022, including all cohort and/or case-control studies that examined occupational exposure to endotoxins and SCLC. Risk of bias was assessed using the U.S. Office of Health Assessment and Translation tool. A random effects model was applied, publication bias were assessed, and a sensitivity analysis was conducted. Four papers were selected for meta-analysis purposes. A total of 144 incident cases of SCLC and 897 population or hospital controls were included. Occupational exposure to endotoxins was considered for textile/leather industry and agricultural sector workers exposed to endotoxins originating from wool, cotton, or leather dust. Except for one study, all investigations were classified as having a low probability of risk of biases. The results of the meta-analysis were not statistically significant (pooled OR: 0.86; 95% CI:0.69-1.08). In addition, neither between-study heterogeneity (I2=0%;p=0.92) nor publication bias was observed (p=0.49). The results of the sensitivity analysis, after including five studies that assessed the risk of SCLC among textile industry and crop/livestock farm workers (not specifically exposed to endotoxins), showed a negative statistically non-significant association and low between-study heterogeneity (pooled OR: 0.90; 95% CI:0.79-1.02; I2=22%;p=0.23). Subjects exposed to occupational exposure to endotoxins seem to exhibit a negative association with the development of SCLC, although the results are not conclusive.

Asbestos exposure and small cell lung cancer: Systematic review and meta-analysis.

Asbestos is a mineral that is carcinogenic to humans. Its use has been banned in many occidental countries yet it is still produced in the United States, and materials that contain asbestos remain in many occupational settings and indoor environments. Even though asbestos carcinogenicity is well known, there is scant literature on its specific effects regarding small cell lung cancer (SCLC). We therefore conducted a systematic review and meta-analysis to determine SCLC risk among workers exposed to asbestos. A systematic search of the literature was conducted to identify studies which reported occupational exposure to asbestos and SCLC-related deaths and/or incidence. We identified seven case-control studies that included 3,231 SCLC cases; four studies reported smoking-adjusted risks. A significantly increased risk of SCLC (pooled OR 1.89; 95% CI, 1.25-2.86) was observed on pooling studies on men (six studies) that displayed moderate heterogeneity (I2 = 46.0%). Overall, our synthesis suggests that occupational exposure to asbestos significantly increases the risk of SCLC on men.

Small cell lung cancer patients treated with immune checkpoint inhibitor: a systematic literature review of treatment efficacy, safety and quality of life.

BACKGROUND: This systematic literature review examines the current immune checkpoint inhibitors treatment paradigms, treatment gaps and unmet needs for treating SCLC with respect to efficacy, safety, health related quality of life (HRQoL) and cost-effectiveness. METHODS: A search strategy was developed and executed using the National Library of Medicine bibliographic database (PubMed), Cochrane Library, Embase and Google Scholar. Data regarding efficacy, safety, cost-effectiveness and HRQoL were extracted and entered in a data extraction sheet created a priori. RESULTS: A total of 4961 patients were comprised in all the 12 studies combined. All the studies focus on extensive stage SCLC (ES-SCLC) and not limited stage SCLC (LS-SCLC). All studies used an ICI as the intervention arm and chemotherapy as the control arm. A statistically significant increase in overall survival (OS) and progression free survival (PFS) was observed when ICIs were added to chemotherapy, especially atezolizumab and durvalumab. ICIs in SCLC resulted in immune-related toxicities that have been well-documented in prior immunotherapy trials; their addition to cytotoxic chemotherapy did not worsen chemotherapy-related toxicities. Out of 12 studies, only 3 (25%) included measures to assess the impact of immunotherapy on SCLC patients' HRQoL. Although domain level scores were limited, the addition of ICIs did not seem to worsen symptoms. Two studies conducted a cost-effectiveness analysis of the combination of atezolizumab plus chemotherapy vs. chemotherapy. The addition of atezolizumab to chemotherapy was not found to be cost-effective in either study. CONCLUSION: Combining ICIs with chemotherapy enhanced OS and PFS as well as not worsening HRQoL. Among all ICIs, PD-L1 inhibitors showed better effectiveness. Future studies should focus on real-world settings and more clinical trials using ICIs for not only ES-SCLC but also LS-SCLC.

Budget impact analysis of trilaciclib for decreasing the incidence of chemotherapy-induced myelosuppression in patients with extensive-stage small cell lung cancer in the United States.

BACKGROUND: Chemotherapy-induced myelosuppression, which commonly manifests as neutropenia, anemia, and/or thrombocytopenia, is a frequent and severe complication of standard treatment regimens for patients with extensive-stage small cell lung cancer (ES-SCLC). Trilaciclib is a first-in-class myeloprotective therapy indicated to decrease the incidence of chemotherapy-induced myelosuppression when administered prior to a platinum-/etoposide-containing regimen or topotecan-containing regimen for ES-SCLC. OBJECTIVE: To estimate the budget impact of administering trilaciclib prior to chemotherapy to manage chemotherapy-induced myelosuppression in adults with ES-SCLC from a US payer perspective. METHODS: A budget impact model was developed to assess the impact of introducing trilaciclib to a hypothetical 1 million-member health insurance plan. The model compared 2 market scenarios: a current scenario of standard treatments for ES-SCLC without trilaciclib, and an alternative scenario of standard treatment plus trilaciclib. Population, clinical, and cost inputs were derived from published literature and trilaciclib clinical trial data. Model outcomes included the number of myelosuppressive adverse events (AEs), costs of treatment, costs of AE management, total cost, and per-member per-month (PMPM) costs. The budget impact of trilaciclib was calculated as the difference in cost (2021 US dollars) between the 2 scenarios over a 1- to 5-year time horizon. Scenario and deterministic sensitivity analyses were conducted to assess uncertainty around key model inputs. RESULTS: An estimated total of 301 patients were eligible for treatment with trilaciclib over a 5-year period. The use of trilaciclib was estimated to reduce the number of myelosuppressive AEs over a 5-year period (events avoided included 108 for neutropenia, 7 for febrile neutropenia, 23 for anemia, and 46 for thrombocytopenia) compared with the scenario without trilaciclib. The adoption of trilaciclib was associated with a cost saving of $801,254 ($0.013 PMPM) over 5 years. The acquisition cost for trilaciclib ($3,704,199) was offset by the reduction in AE management cost ($4,282,748) and reduction in prophylactic granulocyte colony-stimulating factor use ($222,704). The cost savings associated with trilaciclib began in year 1 (total $34,388; $0.003 PMPM) and accrued over time. CONCLUSIONS: The acquisition cost of trilaciclib is projected to be offset by a reduction in the costs of managing AEs related to myelosuppression when added to standard chemotherapy regimens for ES-SCLC. The net budget impact of trilaciclib is estimated to be a cost saving. DISCLOSURES: This research was funded by G1 Therapeutics, Inc., and implemented by ZS Associates, an independent consultancy that collated the model inputs and performed the budget impact analysis. The study sponsor was involved in the study design; collection, analysis, and interpretation of data; writing of the report; and the decision to submit the report for publication. The journal open access fee was funded by G1 Therapeutics, Inc. Moran, Chioda, and Huang are employed by G1 Therapeutics, Inc. Chioda and Huang report stocks and stock options for G1 Therapeutics, Inc. Goyal and Deniz are employed by ZS Associates. Goyal reports consulting fees from G1 Therapeutics, Inc. Abraham reports consulting fees from Coherus, G1 Therapeutics, Inc. (unrelated to this study and manuscript), Mylan/Viatris, and Sandoz and participation on a data safety monitoring board or advisory board for G1 Therapeutics, Inc. MacDonald reports consulting fees from Coherus, G1 Therapeutics, Inc. (unrelated to this study and manuscript), Mylan/Viatris, and Sandoz. Deniz reports no disclosures. A synopsis of the current study was presented in poster format at the Virtual AMCP Annual Meeting, April 12-16, 2021.

Metabolic Disposition of Lurbinectedin, a Potent Selective Inhibitor of Active Transcription of Protein-Coding Genes, in Nonclinical Species and Patients.

Lurbinectedin is a novel and potent selective inhibitor of active transcription of protein-coding genes, triggering apoptosis of cancerous cells. It has been approved for the treatment of patients with metastatic small-cell lung cancer with disease progression on or after platinum-based chemotherapy. Studies exploring the disposition and metabolism of lurbinectedin were performed in vitro and in vivo (by intravenous administration of lurbinectedin). Low blood cell partitioning for lurbinectedin in rats, nonhuman primates (NHP), and humans was determined as 23.4%, 29.8%, and 9.8%, respectively. Protein binding was very high (>95%) in total plasma (rat, NHP, and human), albumin, and α-1-acid glycoprotein (both human). In vitro, lurbinectedin underwent intense liver microsome-mediated metabolism-in 10 minutes, 80% of the compound is metabolized in human-with CYP3A4 being the isoform involved in that metabolism. Results also showed NHPs being the nonclinical species which, metabolically, most closely resembles humans. Mass balance studies performed in rats (both genders), NHPs (male only), and patients (both genders) demonstrated that the principal route of excretion of 14C-lurbinectedin-related radioactivity was through the feces (88.7% ± 10.1% in patients), with only a minor fraction recovered from the urine (5.6% ± 2.0% in patients). In plasma samples, the majority of lurbinectedin-related radioactivity was attributed to unchanged compound (95% ± 3.1% and 70.2% ± 10.9% in NHPs and humans, respectively). Plasma metabolic profiling demonstrated the major (% compared with unchanged compound) circulating metabolites were N-Desmethyl-lurbinectedin (0.4% ± 0.2% and 10.4% ± 2.2% in NHPs and patients, respectively) and 1',3'-Desmethylene-lurbinectedin (0.9% ± 0.7% and 14.3% ± 10.4% in NHP and patients, respectively). SIGNIFICANCE STATEMENT: Lurbinectedin is a novel and potent selective inhibitor of active transcription of protein-coding genes, triggering apoptosis of cancerous cells, and was recently approved for the treatment of patients with metastatic small-cell lung cancer with disease progression on or after platinum-based chemotherapy. The present study provides a complete set of information on the pharmacokinetics, biotransformation, and elimination of 14C-lurbinectedin and its metabolites, following a single intravenous administration to nonclinical species (rats and nonhuman primates) and patients.

Carrelizumab combined with anlotinib in the treatment of extensive-stage small cell lung cancer: A case report.

RATIONALE: The emergence of immune checkpoint inhibitors has brought new breakthroughs in the treatment of small cell lung cancer (SCLC). Programmed cell death-ligand 1 inhibitors combined with chemotherapy have been approved for the first-line treatment of extensive-stage small cell lung cancer (ES-SCLC). However, programmed death 1 inhibitors have limited efficacy in the treatment of SCLC. The reason may be related to the abnormal vascular state in the tumor microenvironment. PATIENT CONCERNS: A 55-year-old male patient, presenting cough and sputum for 1 month. DIAGNOSES: The patient was clinically diagnosed with SCLC and staged as ES-SCLC. INTERVENTIONS: Etoposide combined with lobaplatin treatment every 3 weeks for 4 cycles, evaluate as progressive disease. On the basis of the original plan, combined with camrelizumab for 2 cycles, evaluation as progressive disease. Then, the patient was treated with intravenous infusion of camrelizumab plus oral anlotinib. After 4 cycles, evaluation as partial response. Then we continued to use camrelizumab combined with anlotinib treatment for the patient. At the end of 26 cycles, the chest computed tomography examination revealed that the patient had achieved complete remission. OUTCOMES: After treated with carrelizumab combined with anlotinib for 26 cycles, the curative effect was evaluated as complete remission, progression-free survival was 24 months and there was no immune-related adverse reaction during treatment period. Besides, the patient developed complicated hand-foot syndrome, but this symptom was significantly relieved after reducing the dosage of anlotinib. LESSONS: In this case, antiangiogenesis combined with programmed death 1 inhibitors significantly inhibited tumor progression. It also indicated that anlotinib concurrent carrelizumab may be a superior choice for ES-SCLC. Further clinical trials required to confifirm its effificacy and safety.

Small cell transformation of non-small cell lung cancer on immune checkpoint inhibitors: uncommon or under-recognized?

BACKGROUND: Histological transformation of oncogene-driven lung adenocarcinoma to small cell lung cancer (SCLC) following treatment with tyrosine kinase inhibitors (TKIs) is a well-described phenomenon. Whether a similar transformation may drive acquired resistance to immune checkpoint inhibitors (ICPIs) in non-SCLC (NSCLC) is uncertain. Hence, tissue biopsies are not universally recommended at progression of NSCLC on ICPIs, unlike TKIs. CASE PRESENTATION: We report a case of a woman in her mid-60s with a 35 pack-years tobacco history and stage IV squamous cell lung carcinoma with no targetable genomic alterations, whose disease progressed within 4 months of first line carboplatin/gemcitabine therapy. Her treatment was switched to second line nivolumab monotherapy which resulted in sustained partial response lasting 21 months. She subsequently developed rapid, bulky progression of mediastinal disease. Biopsy showed transformation to SCLC. Comparison of genomic profiling results from the initial NSCLC diagnosis and SCLC transformation revealed near-identical tumor profiles. Her disease responded to next line carboplatin/etoposide, though lasting for only 10 months. She died 14 months after detection of neuroendocrine transformation of her NSCLC. SYSTEMATIC REVIEW: We performed a systematic review of the literature to identify similar cases of NSCLC-to-small cell transformation on ICPIs. Nine patients, including our index case, were identified, with seven (77.8%) on nivolumab and two (22.2%) on pembrolizumab monotherapy. Median survival time since small cell transformation was 13.0 months (95% CI 2.0 to 16.0). Using our patient case as a framework, we further discuss the lack of consensus criteria to distinguish small cell transformation from de novo metachronous SCLC. CONCLUSIONS: Histological transformation to SCLC is a potential mechanism of acquired resistance to ICPIs in NSCLC. Repeat tissue biopsies should be considered at the time of progression, similar to oncogene-directed therapies. Prospective larger studies are warranted to further characterize NSCLC-to-small cell transformation on ICPIs using molecular fingerprinting with paired tumor genomic profiles, evaluation of neuroendocrine features at baseline and consideration of initial response.

Primary ovarian small cell carcinoma of pulmonary type with coexisting endometrial carcinoma in a breast cancer patient receiving tamoxifen: A case report and literature review.

RATIONALE: Small cell carcinoma of the ovary (SCCO) is a rare and aggressive extra-pulmonary variant of small cell tumors of uncertain histogenesis. The pathogenesis and optimal treatment of SCCO is unclear. We present a very rare case of a synchronous primary ovarian small cell carcinoma and endometrioid adenocarcinoma of the uterus in a patient after 2 years of tamoxifen treatment for breast cancer. This is the first such report in the English literature. PATIENT CONCERNS: A 46-year-old woman had a history of left breast cancer that was treated with a simple mastectomy and sentinel lymph node biopsy in 2013. The post-operative pathology was invasive ductal carcinoma of the left breast. she had been taking tamoxifen for 2 years. The patient underwent an exploratory laparotomy to reduce the tumor burden, improve bowel compression symptoms, and promote defecation in 2015. The post-operative pathology revealed a rare, simultaneous occurrence of two tumors (endometrial adenocarcinoma and SCCO [pulmonary type]). DIAGNOSES: Primary ovarian small cell carcinoma of pulmonary type with coexisting endometrial carcinoma in a breast cancer patient. INTERVENTIONS: The patient received 3 courses of chemotherapy after operation. The effect was not apparent and the general health status was poor. OUTCOMES: The patient died of progressive disease 7 months post-operatively. LESSONS: The present case suggests that tamoxifen use might be among many etiologic factors in SCCO development. Despite its rarity, SCCO requires a high degree of attention in clinical work because it is an aggressive tumor that has a poor prognosis.

Mechanisms of acquired resistance to first- and second-generation EGFR tyrosine kinase inhibitors.

Patients with non-small-cell lung cancer (NSCLC) whose tumours harbour activating mutations within the epidermal growth factor receptor (EGFR) frequently derive significant clinical and radiographic benefits from treatment with EGFR tyrosine kinase inhibitors (TKIs). As such, prospective identification of EGFR mutations is now the standard of care worldwide. However, acquired therapeutic resistance to these agents invariably develops. Over the past 10 years, great strides have been made in defining the molecular mechanisms of EGFR TKI resistance in an effort to design rational strategies to overcome this acquired drug resistance. Approximately 60% of patients with acquired resistance to the EGFR TKIs (erlotinib, gefitinib, and afatinib) develop a new mutation within the drug target. This mutation-T790M-has been shown to alter drug binding and enzymatic activity of the mutant EGF receptor. Less common mechanisms of acquired resistance include MET amplification, ERBB2 amplification, transformation to small-cell lung cancer, and others. Here, we present a condensed overview of the literature on EGFR-mutant NSCLC, paying particular attention to mechanisms of drug resistance, recent clinical trial results, and novel strategies for identifying and confronting drug resistance, while also striving to identify gaps in current knowledge. These advances are rapidly altering the treatment landscape for EGFR-mutant NSCLC, expanding the armamentarium of available therapies to maximize patient benefit.

[Hyponatremia in a 58-year-old female patient with EGFR-positive lung adenocarcinoma]. / Hyponatriämie bei einer 58-jährigen Patientin mit einem EGFR-positiven pulmonalen Adenokarzinom.

The case of a 58-year old female patient with epidermal growth factor-positive pulmonary adenocarcinoma treated with the tyrosine kinase inhibitor afatinib is reported. After several months of first-line therapy the patient developed severe hyponatremia and tumor reassessment revealed a progressive course of the lung cancer. Rebiopsy showed transformation of the tumor into small-cell lung cancer. Therapy with afatinib was stopped immediately and platin-based chemotherapy was started. This case shows that tumor transformation under tyrosine kinase inhibitor therapy from non-small-cell into small-cell lung cancer can occur in rare cases.

Long-term exposure to fine particulate matter air pollution and the risk of lung cancer among participants of the Canadian National Breast Screening Study.

Recently, air pollution has been classified as a carcinogen largely on the evidence of epidemiological studies of lung cancer. However, there have been few prospective studies that have evaluated associations between fine particulate matter (PM2.5 ) and cancer at lower concentrations. We conducted a prospective analysis of 89,234 women enrolled in the Canadian National Breast Screening Study between 1980 and 1985, and for whom residential measures of PM2.5 could be assigned. The cohort was linked to the Canadian Cancer Registry to identify incident lung cancers through 2004. Surface PM2.5 concentrations were estimated using satellite data. Cox proportional hazards models were used to characterize associations between PM2.5 and lung cancer. Hazard ratios (HRs) and 95% confidence intervals (CIs) computed from these models were adjusted for several individual-level characteristics, including smoking. The cohort was composed predominantly of Canadian-born (82%), married (80%) women with a median PM2.5 exposure of 9.1 µg/m(3) . In total, 932 participants developed lung cancer. In fully adjusted models, a 10 µg/m(3) increase in PM2.5 was associated with an elevated risk of lung cancer (HR: 1.34; 95% CI = 1.10, 1.65). The strongest associations were observed with small cell carcinoma (HR: 1.53; 95% CI = 0.93, 2.53) and adenocarcinoma (HR: 1.44; 95% CI = 1.06, 1.97). Stratified analyses suggested increased PM2.5 risks were limited to those who smoked cigarettes. Our findings are consistent with previous epidemiological investigations of long-term exposure to PM2.5 and lung cancer. Importantly, they suggest associations persist at lower concentrations such as those currently found in Canadian cities.

Transformation to SCLC after Treatment with the ALK Inhibitor Alectinib.

We report an anaplastic lymphoma receptor tyrosine kinase gene (ALK)-positive patient who showed a paradoxical response to the ALK inhibitor alectinib; the primary lesion increased in size, whereas other metastatic lesions decreased markedly. A biopsy of the primary lesion confirmed an ALK rearrangement; however, the tumor had transformed histologically into small cell lung cancer. The lack of reports of small cell lung cancer transformation in ALK-positive patients implies that this outcome was unusual; this patient was treated with alectinib, which is more selective and has a greater inhibitory effect than crizotinib. This case may reveal resistance mechanisms that differ according to the agent used for treatment.

The Association Between Alcohol Consumption and Lung Carcinoma by Histological Subtype.

Alcohol is a carcinogen suspected of increasing lung cancer risk. Therefore, we prospectively evaluated the relationship between alcohol consumption and lung carcinoma in 492,902 persons from the National Institutes of Health-AARP Diet and Health Study. We used Cox models to calculate hazard ratios and 95% confidence intervals, adjusting for tobacco smoking and other potential confounders. Between 1995/1996 and December 31, 2006, there were 10,227 incident cases of lung carcinoma, classified as adenocarcinoma (n = 4,036), squamous cell carcinoma (n = 1,998), small cell carcinoma (n = 1,524), undifferentiated carcinoma (n = 559), and other (n = 2,110). Compared with nondrinking, alcohol consumption was associated with a modest nonlinear reduction in total lung carcinoma risk at lower levels of consumption (for 0.5-<1 drink/day, HR = 0.89, 95% confidence interval: 0.82, 0.96) but a modest increase in risk in the highest category (for ≥7 drinks/day, HR = 1.11, 95% confidence interval: 1.00, 1.24). Regarding histological type, alcohol was associated with a nonlinear reduction in squamous cell carcinoma that became attenuated as consumption increased and a modest increase in adenocarcinoma among heavier drinkers. Cubic spline models confirmed these findings. Our data suggest that the relationship between alcohol consumption and lung carcinoma differs by histological subtype.

NOTCH1, HIF1A and other cancer-related proteins in lung tissue from uranium miners--variation by occupational exposure and subtype of lung cancer.

BACKGROUND: Radon and arsenic are established pulmonary carcinogens. We investigated the association of cumulative exposure to these carcinogens with NOTCH1, HIF1A and other cancer-specific proteins in lung tissue from uranium miners. METHODOLOGY/PRINCIPAL FINDINGS: Paraffin-embedded tissue of 147 miners was randomly selected from an autopsy repository by type of lung tissue, comprising adenocarcinoma (AdCa), squamous cell carcinoma (SqCC), small cell lung cancer (SCLC), and cancer-free tissue. Within each stratum, we additionally stratified by low or high level of exposure to radon or arsenic. Lifetime exposure to radon and arsenic was estimated using a quantitative job-exposure matrix developed for uranium mining. For 22 cancer-related proteins, immunohistochemical scores were calculated from the intensity and percentage of stained cells. We explored the associations of these scores with cumulative exposure to radon and arsenic with Spearman rank correlation coefficients (r(s)). Occupational exposure was associated with an up-regulation of NOTCH1 (radon r(s) = 0.18, 95% CI 0.02-0.33; arsenic: r(s) = 0.23, 95% CI 0.07-0.38). Moreover, we investigated whether these cancer-related proteins can classify lung cancer using supervised and unsupervised classification. MUC1 classified lung cancer from cancer-free tissue with a failure rate of 2.1%. A two-protein signature discriminated SCLC (HIF1A low), AdCa (NKX2-1 high), and SqCC (NKX2-1 low) with a failure rate of 8.4%. CONCLUSIONS/SIGNIFICANCE: These results suggest that the radiation-sensitive protein NOTCH1 can be up-regulated in lung tissue from uranium miners by level of exposure to pulmonary carcinogens. We evaluated a three-protein signature consisting of a physiological protein (MUC1), a cancer-specific protein (HIF1A), and a lineage-specific protein (NKX2-1) that could discriminate lung cancer and its major subtypes with a low failure rate.

Lung cancer decreased sharply in first 5 years after smoking cessation in Chinese men.

BACKGROUND: The rate of decline in lung cancer risk after smoking cessation among male population and the importance of the magnitude of the early decline were not sufficiently defined in the earlier studies. We evaluated the detailed duration-response relationship between years since smoking cessation and lung cancer risk across major histological types in a population-based case-referent study. METHODS: We recruited 1208 consecutive incident cases of primary lung cancer among Chinese males from the largest oncology center in Hong Kong during 2004-2006, and 1069 male community referents frequency-matched in 5-year age groups. We performed unconditional multiple logistic regression and generalized additive model incorporating smoothing spline to model the potential nonlinear effect of years since cessation on lung cancer. RESULTS: All histological types of lung cancer were strongly associated with current smoking. We observed a rapidly decreasing odds ratio of lung cancer (>50%) across all major histological types of lung cancer (except for the large cell type) within the first 5 years of quitting; the odds ratio continued to decrease but at a slower rate in the subsequent years. CONCLUSION: The substantial benefits obtainable within a short period of 5 years' abstinence should convey an encouraging message to chronic smokers, clinicians, and public health workers.

Exposure to beryllium and occurrence of lung cancer: findings from a cox proportional hazards analysis of data from a retrospective cohort mortality study.

OBJECTIVE: The objective was to assess highly confounded patterns in a standardized mortality ratio (SMR) analysis of lung cancer in beryllium worker cohorts. METHODS: We used Cox proportional hazards single- and multi-variate models to assess confounding and the SMR patterns. RESULTS: We confirmed the lack of association of lung cancer with time worked. We could not confirm the original study's finding of lung cancer highly associated with earlier plants and or with workers hired in the 1940s compared to the 1950s. The pattern of higher rates of lung cancer with increasing latency was attenuated when covariates were added to the model. We could not exclude that the lower SMR and hazard ratios for workers hired in the 1960s might be related to assumed lower beryllium exposures. CONCLUSION: The patterns observed provide little support for an association of lung cancer with beryllium work factors. This result is likely due to the absence in the original study of a significant overall excess of lung cancer after smoking adjustment.

Lung cancer in a U.S. population with low to moderate arsenic exposure.

BACKGROUND: Little is known about the carcinogenic potential of arsenic in areas with low to moderate concentrations of arsenic (< 100 microg/L) in drinking water. OBJECTIVES: We examined associations between arsenic and lung cancer. METHODS: A population-based case-control study of primary incident lung cancer was conducted in 10 counties in two U.S. states, New Hampshire and Vermont. The study included 223 lung cancer cases and 238 controls, each of whom provided toenail clippings for arsenic exposure measurement by inductively coupled-plasma mass spectrometry. We estimated odds ratios (ORs) of the association between arsenic exposure and lung cancer using unconditional logistic regression with adjustment for potential confounders (age, sex, race/ethnicity, smoking pack-years, education, body mass index, fish servings per week, and toenail selenium level). RESULTS: Arsenic exposure was associated with small-cell and squamous-cell carcinoma of the lung [OR = 2.75; 95% confidence interval (CI), 1.00-7.57] for toenail arsenic concentration > or = 0.114 microg/g, versus < 0.05 microg/g. A history of lung disease (bronchitis, chronic obstructive pulmonary disease, or fibrosis) was positively associated with lung cancer (OR = 2.86; 95% CI, 1.39-5.91). We also observed an elevated risk of lung cancer among participants with a history of lung disease and toenail arsenic > or = 0.05 microg/g (OR = 4.78; 95% CI, 1.87-12.2) than among individuals with low toenail arsenic and no history of lung disease. CONCLUSION: Although this study supports the possibility of an increased risk of specific lung cancer histologic types at lower levels of arsenic exposure, we recommend large-scale population-based studies.

Exposure to iron and welding fumes and the risk of lung cancer.

OBJECTIVES: Exposure to iron fumes and dust and welding fumes is widespread and may increase the risk of lung cancer. The aim of this study was to identify associations between exposure to iron and welding fumes and the incidence of lung cancer among Finnish men. METHODS: The cohort of all economically active Finnish men, born in 1906-1945, who participated in the national census in 1970 was followed through the Finnish Cancer Registry for lung cancer cases (N=30,137) during 1971-1995. Their census occupations in 1970 were converted to estimates of cumulative exposure to iron and welding fumes with the Finnish job-exposure matrix on the basis of likelihood, average level, and estimated duration of exposure. Relative risk estimates for categorized cumulative exposure were defined by a Poisson regression, adjusted for smoking, socioeconomic status, and exposure to asbestos and silica dust. RESULTS: The relative risks for lung cancer increased as the cumulative exposure to iron and welding fumes increased. Relative risks in the highest exposure category was 1.35 [95% confidence interval (95% CI) 1.05-1.73] for iron and 1.15 (95% CI 0.90-1.46) for welding fumes. The respective relative risks estimated for squamous-cell carcinoma of the lungs were 1.94 (95% CI 1.35-2.78) and 1.55 (95% CI 1.08-2.24). There was no excess risk of small-cell carcinoma in any exposure category. CONCLUSIONS: Occupational exposure to iron and welding fumes was associated with an increase in lung cancer risk, mainly that of squamous-cell carcinoma. The simultaneous exposure to both of these agents and other potential work-related carcinogens complicates the interpretation of the independent roles of the risk factors.