Women and lung cancer: Epidemiology, tumor biology, and emerging trends in clinical research

Acute particulate hexavalent chromium exposure induces DNA double-strand breaks and activates homologous recombination repair in rat lung tissue

Hexavalent chromium [Cr(VI)] is an established human lung carcinogen, but the carcinogenesis mechanism is poorly understood. Chromosome instability, a hallmark of lung cancer, is considered a major driver of Cr(VI)-induced lung cancer. Unrepaired DNA double-strand breaks are the underlying cause, and homologous recombination repair is the primary mechanism preventing Cr(VI)-induced DNA breaks from causing chromosome instability. Cell culture studies show acute Cr(VI) exposure causes DNA double-strand breaks and increases homologous recombination repair activity. However, the ability of Cr(VI)-induced DNA breaks and repair impact has only been reported in cell culture studies. Therefore, we investigated whether acute Cr(VI) exposure could induce breaks and homologous recombination repair in rat lungs. Male and female Wistar rats were acutely exposed to either zinc chromate particles in a saline solution or saline alone by oropharyngeal aspiration. This exposure route resulted in increased Cr levels in each lobe of the lung. We found Cr(VI) induced DNA double-strand breaks in a concentration-dependent manner, with females being more susceptible than males, and induced homologous recombination repair at similar levels in both sexes. Thus, these data show this driving mechanism discovered in cell culture indeed translates to lung tissue in vivo.

Evolution of Diagnoses, Survival, and Costs of Oncological Medical Treatment for Non-Small-Cell Lung Cancer over 20 Years in Osona, Catalonia

Non-small-cell lung cancer (NSCLC) has experienced several diagnostic and therapeutic changes over the past two decades. However, there are few studies conducted with real-world data regarding the evolution of the cost of these new drugs and the corresponding changes in the survival of these patients. We collected data on patients diagnosed with NSCLC from the tumor registry of the University Hospital of Vic from 2002 to 2021. We analyzed the epidemiological and pathological characteristics of these patients, the diverse oncological treatments administered, and the survival outcomes extending at least 18 months post-diagnosis. We also collected data on pharmacological costs, aligning them with the treatments received by each patient to determine the cost associated with individualized treatments. Our study included 905 patients diagnosed with NSCLC. We observed a dynamic shift in histopathological subtypes from squamous carcinoma in the initial years to adenocarcinoma. Regarding the treatment approach, the use of chemotherapy declined over time, replaced by immunotherapy, while molecular therapy showed relative stability. An increase in survival at 18 months after diagnosis was observed in patients with advanced stages over the most recent years of this study, along with the advent of immunotherapy. Mean treatment costs per patient ranged from EUR 1413.16 to EUR 22,029.87 and reached a peak of EUR 48,283.80 in 2017 after the advent of immunotherapy. This retrospective study, based on real-world data, documents the evolution of pathological characteristics, survival rates, and medical treatment costs for NSCLC over the last two decades. After the introduction of immunotherapy, patients in advanced stages showed an improvement in survival at 18 months, coupled with an increase in treatment costs.

Sex-specificity in Surgical Stages of Lung Cancer in Young Adults

Background

Young Patients with lung cancer represent a distinct subset of patients with this neoplasm. Young International studies show increased lung cancer rates in females, while the incidence in males continues to decline. There is evidence to suggest that this trend recurs in younger patients. We studied the effects of gender differences on the incidence of surgical stages of lung cancer in young adults and its mortality rate.

Methods

This study is a retrospective review (2010-2020) of young adults (aged under 45 years) with surgical-stage of lung cancer. We calculated female-to-male differences in incidence rate ratios, tumor characteristics, surgical management, and survival. Cumulative survival curves were generated by the Kaplan-Meier method.

Results

We examined 46 men and 24 women, under 45 years. Female patients were diagnosed at earlier stages. The proportion of stage IA disease was significantly higher in women than in men (46% versus 13%, respectively) (p=0.03). Women were more likely never smokers (42% versus 83%, p=0.02). A histologic subtype, females were more likely to have typical carcinoid tumors (13.54% versus 10.21% for males) (p>0.05). The largest histological type in men was adenocarcinoma (25.53% versus 4.16%, p>0.05). All the patients were operated. Three men had neoadjuvant chemotherapy and one was operated on for cerebral oligometastatic before his chest surgery. Adjuvant chemotherapy was given to 7 women and 21 men. Despite the small number of postoperative complications in our study (n= 8, 11.2%), the male sex was significant in predicting this complication (p<0.05). The mortality rate was 1.4%. The 5-year overall survival rates were 84% in men and 87% in women.

Conclusion

Our study identified sex differences in the incidence and mortality rates for surgical lung cancers in young adults, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined.

Opium use and risk of lung cancer: A multicenter case-control study in Iran

Opium use was recently classified as a human carcinogen for lung cancer by the International Agency for Research on Cancer. We conducted a large, multicenter case-control study evaluating the association between opium use and the risk of lung cancer. We recruited 627 cases and 3477 controls from May 2017 to July 2020. We used unconditional logistic regression analyses to estimate the odds ratios (OR) and 95% confidence intervals (CI) and measured the association between opium use and the risk of lung cancer. The ORs were adjusted for the residential place, age, gender, socioeconomic status, cigarettes, and water pipe smoking. We found a 3.6-fold risk of lung cancer for regular opium users compared to never users (95% CI: 2.9, 4.6). There was a strong dose-response association between a cumulative count of opium use and lung cancer risk. The OR for regular opium use was higher for small cell carcinoma than in other histology (8.3, 95% CI: 4.8, 14.4). The OR of developing lung cancer among opium users was higher in females (7.4, 95% CI: 3.8, 14.5) than in males (3.3, 95% CI: 2.6, 4.2). The OR for users of both opium and tobacco was 13.4 (95% CI: 10.2, 17.7) compared to nonusers of anything. The risk of developing lung cancer is higher in regular opium users, and these results strengthen the conclusions on the carcinogenicity of opium. The association is stronger for small cell carcinoma cases than in other histology.

Hexavalent chromium increases the metabolism and genotoxicity of aromatic amine carcinogens 4-aminobiphenyl and β-naphthylamine in immortalized human lung epithelial cells

Humans are exposed to carcinogenic chemicals via occupational and environmental exposures. Common chemicals of concern that can occur in exposures together are aromatic amines (e.g., 4-aminobiphenyl [4-ABP] and β-naphthylamine [BNA]) and hexavalent chromium (Cr[VI]). Arylamine N-acetyltransferases 1 and 2 (NAT1 and NAT2) are key to the metabolism of aromatic amines and their genotoxicity. The effects of Cr(VI) on the metabolism of aromatic amines remains unknown as well as how it may affect their ensuing toxicity. The objective of the research presented here is to investigate the effects of Cr(VI) on the metabolism and genotoxicity of 4-ABP and BNA in immortalized human lung epithelial cells (BEP2D) expressing NAT1 and NAT2. Exposure to Cr(VI) for 48 h increased NAT1 activity (linear regression analysis: P < 0.0001) as measured by N-acetylation of para-aminobenzoic acid (PABA) in BEP2D cells but not NAT2 N-acetylation of sulfamethazine, which are prototypic NAT1 and NAT2 substrates respectively. Cr(VI) also increased the N-acetylation of 4-ABP and BNA. In BEP2D cells the N-acetylation of 4-ABP (1-3 μM) exhibited a dose-dependent increase (linear regression analysis: P < 0.05) following co-incubation with 0-3 μM Cr(VI). In BEP2D cells, incubation with Cr(VI) caused dose-dependent increases (linear regression analysis: P < 0.01) in expression of CYP1A1 protein and catalytic activity. For genotoxicity, BEP2D cells were exposed to 4-ABP or BNA with/without Cr(VI) for 48 h. We observed dose-dependent increases (linear regression analysis: P < 0.01) in phospho-γH2AX protein expression for combined treatment of 4-ABP or BNA with Cr(VI). Further using a CYP1A1 inhibitor (α-naphthoflavone) and NAT1 siRNA, we found that CYP1A1 inhibition did not reduce the increased N-acetylation or genotoxicity of BNA by Cr(VI), while NAT1 inhibition did reduce increases in BNA N-acetylation and genotoxicity by Cr(VI). We conclude that during co-exposure of aromatic amines and Cr(VI) in human lung cells, Cr(VI) increased NAT1 activity contributing to increased 4-ABP and BNA genotoxicity.

New Implications of Patients’ Sex in Today’s Lung Cancer Management

Simple Summary

We aim to raise awareness that sex is an important factor to take into account in modern-day thoracic oncology practice. Summarized, women should be specifically targeted in smoking cessation campaigns and sex-specific barriers should be addressed. Women present more often with adenocarcinoma histology and EGFR/ALK alterations, as lung cancer in never-smokers is more common in women compared to men. Lung cancer in female patients may show a poorer response to immune checkpoint inhibition; therefore, the addition of chemotherapy should be considered. On the other hand, women experience more benefits from targeted therapy against EGFR. In general, prognosis for women is better compared to that in men. Lung cancer screening trials report that women derive more benefit from screening, although they have not been designed for women. Future trial designs should take this into account and encourage participation of women.

Abstract

This paper describes where and how sex matters in today’s management of lung cancer. We consecutively describe the differences between males and females in lung cancer demographics; sex-based differences in the immune system (including the poorer outcomes in women who are treated with immunotherapy but no chemotherapy); the presence of oncogenic drivers and the response to targeted therapies according to sex; the greater benefit women derive from lung cancer screening and why they get screened less; and finally, the barriers to smoking cessation that women experience. We conclude that sex is an important but often overlooked factor in modern-day thoracic oncology practice.

Lung Cancer in Women

BACKGROUND

Lung cancer is the leading cause of cancer-related death for women in the United States. Clinical characteristics, histology, epidemiology, and treatment responses are unique for women with lung cancer.

METHODS

Literature search of MEDLINE publications from 1989 to 2021 was conducted for lung cancer in women. Subsequent narrative review focused on identified differences in risk factors, diagnosis, and treatment of importance to the surgical care of these patients.

RESULTS

Studies investigating lung cancer, in which sex-differences are explored, demonstrated differences in risk factors, histology, and treatment response among women, with a significant post-surgical survival advantage over men (41.8 months vs 26.8 months, p=0.007) and greater clinical benefit from anti-PD1 combined with chemotherapy (HR=0.44, 95% CI: 0.25-0.76) compared with men (HR=0.76, 95% CI: 0.64-0.91). Smoking remains a dominant risk factor and multiple clinical trials suggest lung cancer screening provides greater benefit for women. However, young non-smoking patients with lung cancer are 2-fold more likely to be female, advocating for broader sex-based screening criteria. Potential roles of genetic mutations, estrogen signaling, and infectious elements in sex-based differences in presentation, histology, prognosis and treatment response are explored.

CONCLUSIONS

Overall, much remains unknown regarding how sex influences lung cancer risk, treatment decisions and outcomes. However, evidence of specific differences in presentation, environmental risk, molecular drivers, and mutational burden support the need to better leverage these sex-associated differences to further improve detection, diagnosis, surgical outcomes and systemic regimens in order to advance the overall care strategy for women with lung cancer.

Addressing Gender Disparities in Lung Cancer Screening Eligibility: USPSTF versus PLCOm2012 Criteria

BACKGROUND

Lung cancer is the leading cause of cancer death in women in the United States. Prospective randomized lung screening trials suggest a greater lung cancer mortality benefit from screening women compared to men.

RESEARCH QUESTION

Do the United States Preventative Services Task Force (USPSTF) lung screening guidelines that are based solely on age and smoking history contribute to gender disparities in eligibility, and if so, does the use of the PLCOm2012 risk prediction model that is based on 11 predictors of lung cancer reduce gender disparities?

STUDY DESIGN AND METHODS

This retrospective analysis of 883 lung cancer cases in the Chicago Race Eligibility for Screening Cohort (CREST) determined the sensitivity of USPSTF versus PLCOm2012 eligibility criteria, stratified by gender. For comparisons to the USPSTF 2013and the recently published USPSTF 2021(released March 9^th, 2021) eligibility criteria, the PLCOm2012 model was used with risk thresholds of ≥1.7%/6y and >1.0%/6y, respectively.

RESULTS

The sensitivities for screening by the USPSTF 2013were 46.7% for women and 64.6% for men (p=0.003) and by the USPSTF 2021were 56.8% and 71.8%, respectively (p=0.02). In contrast, the PLCOm2012 ≥1.7%/6y sensitivities were 64.6% and 70.4%, respectively, and the PLCOm2012 ≥1.0%/6y sensitivities were 77.4% and 82.4%, respectively. The PLCOm2012 differences in sensitivity using ≥1.7%/6y and ≥1.0%/6y thresholds between women and men were nonsignificant (both p=0.07). Compared to men, women were more likely to be ineligible by the USPSTF 2021criteria because their smoking exposures were <20 pack-years (22.8% vs 14.8%, OR_{Women vs Men} 1.70, 95% CI 1.19-2.44; p=0.002) and 27% of these ineligible women were eligible by the PLCOm2012 >1.0%/6y criteria.

INTERPRETATION

Although the USPSTF 2021eligibility criteria are more sensitive than the USPSTF 2013guidelines, there remains gender disparities in eligibility. Adding the PLCOm2012 risk prediction model to the USPSTF guidelines would improve sensitivity and attenuate gender disparities.

Risk of lung cancer among women in relation to lifetime history of tobacco smoking: a population-based case-control study in France (the WELCA study)

Background

This study aims to provide new insights on the role of smoking patterns and cigarette dependence in female lung cancer, and to examine differences by histological subtype.

Methods

We conducted a population-based case-control study in the great Paris area among women including 716 incident cases diagnosed between 2014 and 2017 and 757 age-matched controls. Detailed data on smoking history was collected during in-person interviews to assess intensity and duration of tobacco smoking, time since cessation, smoking habits (depth of smoke inhalation, use of filter, type of tobacco, and type of cigarettes) and Fagerström test for cigarette dependence. The comprehensive smoking index (CSI), a score modelling the combined effects of intensity, duration and time since quitting smoking was determined for each subject. Multivariable logistic regression models were fitted to calculate odds ratios (ORs) and their confidence intervals (95%CI) of lung cancer associated with smoking variables.

Results

Lung cancer risk increased linearly with intensity and duration of tobacco smoking while it decreased with time since cessation, to reach the risk in never-smokers after 20 years of abstinence. The combined effect of intensity and duration of tobacco smoking was more than multiplicative (p-interaction 0.012). The OR in the highest vs the lowest quartile of CSI was 12.64 (95%CI 8.50; 18.80) (p-trend < 0.001). The risk of small cell or squamous cell carcinomas increased with the CSI more sharply than the risk of adenocarcinomas. Deep smoke inhalation, dark vs blond tobacco, conventional vs light cigarettes, and unfiltered vs filtered cigarettes, as well as having mixed smoking habits, were found to be independent risk factors. Having high cigarette addiction behaviours also increased the risk after adjusting for CSI.

Conclusion

This study provides additional insights on the effects of tobacco smoking patterns on lung cancer risk among women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08433-z.

ERα-dependent estrogen-TNFα signaling crosstalk increases cisplatin tolerance and migration of lung adenocarcinoma cells

Lung adenocarcinoma is the most common type of lung cancer in women. Our previous studies demonstrated that 17β-estradiol (E2) promoted lung adenocarcinoma cell proliferation and tumor growth through estrogen receptor ERα. Transcriptomic analysis suggested that E2 potentiated TNFα-NFκB signaling in ERα-expressing lung adenocarcinoma cells. This study further demonstrated that E2 increased TNFα receptor expression and TNFα-triggered NFκB activity in ERα-expressing cells. E2-activated ERα had no physical association with NFκB p65/p50 heterodimer but facilitated TNFα-initiated IκBα degradation, NFκB nuclear translocation, and S468/S536 phosphorylation of p65 essential for NFκB activity. While knockdown of ERα prevented E2 from boosting NFκB activity, antiestrogen ICI 182,780 stimulated NFκB activity like E2. Inhibition of GSK3β hampered E2:ERα-promoted NFκB activity and abolished S468 phosphorylation of p65, suggesting that GSK3β played a role in the E2-TNFα signaling crosstalk. In ERα-expressing cells, E2 and TNFα synergistically regulated many genes that were not typically responsive to either E2 or TNFα. Functional analysis of microarray data inferred that E2/TNFα-induced transcriptomic changes improved cell survival and movement. Viability and colony formation assays validated that E2 and TNFα together increased cisplatin tolerance of ERα-expressing cells. Wound healing assays also confirmed that E2/TNFα cotreatment increased cell migration in an ERα-dependent manner. E2/TNFα-induced dysregulation of genes such as cell survival and movement-associated genes, proto-oncogenes, metallothioneins and histone core genes was correlated with poor overall survival in patients. In summary, E2 and TNFα engaged in an ERα-dependent positive crosstalk in lung adenocarcinoma cells, consequently increasing NFκB activation, cisplatin tolerance and cell migration and worsening prognosis.

Effect of antibiotic use on the efficacy of nivolumab in the treatment of advanced/metastatic non-small cell lung cancer: A meta-analysis

This study evaluates the impact of the use of antibiotics on the effectiveness of nivolumab in the treatment of advanced/metastatic non-small cell lung cancer (NSCLC). A literature search was conducted in various electronic databases to identify studies, which evaluated the impact of antibiotic use on the survival of patients with advanced/metastatic NSCLC who have been treated with nivolumab. Six studies, comprising a total of 787 patients with 37.2% females and of age range 30–90 years, were included in the study. A lack of smoking history was reported in 14.4% of the patients. A meta-analysis was conducted in 678 and 713 patients for PFS and OS, respectively. The pooled HR was 1.95 (95% CI: 1.13–3.37, P = 0.016) for PFS and 2.70 (95% CI: 1.81–4.02, P < 0.001) for OS. Among patients exposed to antibiotics, the median PFS and OS were reduced by 1.6 months (95% CI: 1.5–1.7) and 8.8 months (95% CI: 8.5–9.1), respectively. Our study indicates that, among patients with advanced/metastatic NSCLC, the use of antibiotics with nivolumab led to a decrease in the median OS by more than 8 months. Studying the mechanism of the effect of antibiotics on the efficacy of nivolumab in patients with NSCLC should also be prioritized.

Mutation profile of non-small cell lung cancer revealed by next generation sequencing

BACKGROUND

Precision therapy for lung cancer requires comprehensive genomic analyses. Specific effects of targeted therapies have been reported in Asia populations, including Taiwanese, but genomic studies have rarely been performed in these populations.

METHOD

We enrolled 72 patients with non-small cell lung cancer, of whom 61 had adenocarcinoma, 10 had squamous cell carcinoma, and 1 had combined adenocarcinoma and squamous cell carcinoma. Whole-exome or targeted gene sequencing was performed. To identify trunk mutations, we performed whole-exome sequencing in two tumor regions in four patients.

RESULTS

Nineteen known driver mutations in EGFR, PIK3CA, KRAS, CTNNB1, and MET were identified in 34 of the 72 tumors evaluated (47.22%). A comparison with the Cancer Genome Atlas dataset showed that EGFR was mutated at a much higher frequency in our cohort than in Caucasians, whereas KRAS and TP53 mutations were found in only 5.56% and 25% of our Taiwanese patients, respectively. We also identified new mutations in ARID1A, ARID2, CDK12, CHEK2, GNAS, H3F3A, KDM6A, KMT2C, NOTCH1, RB1, RBM10, RUNX1, SETD2, SF3B1, SMARCA4, THRAP3, TP53, and ZMYM2. Moreover, all ClinVar pathogenic variants were trunk mutations present in two regions of a tumor. RNA sequencing revealed that the trunk or branch genes were expressed at similar levels among different tumor regions.

CONCLUSIONS

We identified novel variants potentially associated with lung cancer tumorigenesis. The specific mutation pattern in Taiwanese patients with non-small cell lung cancer may influence targeted therapies.

Hormonal factors in association with lung cancer among Asian women: A pooled analysis from the International Lung Cancer Consortium

Two thousand sixty-four lung cancer cases and 5342 controls were evaluated in this International Lung Cancer Consortium (ILCCO) pooled analysis on estrogen-related hormonal factors and lung cancer in Asian women. Random effect of study site and fixed effect of age, smoking status, comprehensive smoking index and family history of lung cancer were adjusted for in the multivariable logistic regression models. We found that late onset of menarche conferred elevated odds of lung cancer with adjusted odds ratio (OR) of 1.24 (95% confidence interval [CI] = 1.05, 1.45) for 17 years or older, compared to 14 years or younger. Late onset of menopause at 55 years old or older was associated with lung cancer with OR = 1.24 (95% CI = 1.02, 1.51). Nonnatural menopause was associated with an OR of 1.39 (95% CI = 1.13, 1.71). More live births showed reversed association with lung cancer (ORs of 5 or more live births: 0.71 (95% CI = 0.60, 0.84), compared to 0-2 live births (P_trend < 0.001). A later first child delivery seemed associated with an increased susceptibility: OR of 21 to 25 years old: 1.23 (95% CI = 1.06, 1.40), 26 or older: 1.27 (95% CI = 1.06, 1.52), P_trend = .010). The use of oral contraceptives appeared to be protective with an OR of 0.69 (95% CI = 0.57, 0.83). Stronger for adenocarcinoma than squamous cell carcinoma, these relationships were not clearly modified by smoking status, probably because of lower prevalence of smoking. This is a first and largest pooling study of lung cancer among Asian women and the results suggested potential roles of hormone-related pathways in the etiology of this disease.

Comparing cotinine and NNAL verification of self-reported smoking status among lung cancer screening eligible population from the 2007-2014 National Health and Nutrition Examination Survey (NHANES)

Background: Biochemical verification of self-reported smoking status is not common among the population eligible for lung cancer screening (LCS). Methods: We used urinary NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides) and serum cotinine as the gold standard to determine the validity and reliability of self-reported smoking status from the 2007-2014 National Health and Nutrition Examination Survey (NHANES). Results: We found 2.3% (n = 652, equivalent to 5.3 million weighted population) of adults eligible for LCS according to the current United States Preventive Services Task Force guideline. Self-reported current smoking status performed similarly against NNAL and cotinine: sensitivity [89.7% (95%CI: 84.9%-94.5%) vs. 89.5% (95%CI: 84.8%-94.3%)]; specificity [99.7% (95%CI: 99.2%-100.0%) vs. 100% (95%CI:100%-100%)]; positive predictive value (PPV) and negative predictive value (NPV) were 99.8% (95%CI:99.4%-100.0%) versus 100% (95%CI:100%-100%) and 85.3% (95%CI: 79.1%-91.5%) versus 85.1% (95%CI: 79.1%-1.0%), respectively; and Kappa [86.5% (95%CI:80.5%-92.5%) vs. 86.5% (95%CI:80.6%-92.3%)]. Performance measures were better among females than males; worst among the non-Hispanic white and best among other race/ethnicity group. The validity and reliability of self-reported smoking status increased with increasing cutpoint levels of both NNAL and cotinine. Conclusions: Self-reported smoking status among people who are at high risk of lung cancer is reasonably reliable. The difference between using NNAL and cotinine appears to be minimal.

Cancer surveillance among workers in plastics and rubber manufacturing in Ontario, Canada

OBJECTIVE

Occupational exposure to agents in plastics and rubber manufacturing has been associated with elevated risk of certain cancers. We sought to evaluate cancer risk among workers employed in occupations and industries with these exposures as part of an ongoing surveillance programme in Ontario, Canada.

METHODS

The Occupational Disease Surveillance System (ODSS) cohort was established using workers' compensation claims data and includes 2.18 million workers employed from 1983 to 2014. Workers were followed for site-specific cancer diagnoses in the Ontario Cancer Registry through 2016. Cox proportional hazard models were used to estimate adjusted HR and 95% CI.

RESULTS

We identified 81 127 workers employed in plastics and rubber manufacturing industries or materials processing and product fabricating occupations. Compared with all other women in the ODSS, those in materials processing occupations had an elevated rate of lung cancer (HR 1.38, 95% CI 1.20 to 1.58) that was not observed among men. An elevated rate of breast cancer was observed among female labourers (HR 1.36, 95% CI 1.01 to 1.82) and moulders (HR 1.47, 95% CI 0.91 to 2.37) in plastics and rubber product fabricating occupations. Overall, elevated rates were observed for oesophageal, liver, stomach, prostate and kidney cancer in job-specific subgroups, including mixing and blending, bonding and cementing, and labouring. There was little evidence of association for lymphatic or haematopoietic cancers.

CONCLUSIONS

Findings for lung and breast cancer in women are consistent with other studies and warrant further attention in Ontario. Given the relatively young age at end of follow-up, surveillance in these workers should continue as the cohort ages.

Effect of exogenous progesterone administration on cigarette smoking-related symptomology in oral contraceptive users who smoke

Cigarette smoking-related symptomatology (e.g., craving; SRS) is linked to relapse after a quit attempt. SRS varies by menstrual phase, possibly due to variations in sex hormones (e.g., progesterone), though much of the research to-date has relied on observations from the menstrual cycle acting as a proxy for hormone levels. The goal of this study was to examine the effect of exogenous progesterone on SRS during ad libitum smoking and following overnight abstinence. Oral contraceptive users who smoked completed two 9-day crossover testing periods (7 days of ad libitum smoking and 2 days following overnight abstinence) while taking double-blind active/placebo exogenous progesterone. Participants completed questionnaires to measure SRS. The effect of exogenous progesterone and endogenous hormones (progesterone, estradiol, and progesterone-to-estradiol [P/E₂] ratio) on SRS was assessed with paired t-tests and linear mixed effect models. Participants (n = 53) were, on average, 24 years old and smoked 11 cigarettes per day. During ad libitum smoking, a doubling of the P/E₂ ratio was associated with 0.09 points lower anticipated relief from negative affect (95% confidence interval [CI]: 0.03-0.15 points lower; p = 0.008) and 0.11 points lower psychological reward (95% CI: 0.03-0.18 points lower; p = 0.006). After correction for multiple testing, these associations were not statistically significant: anticipated relief from negative effect (p = 0.10) and psychological reward (p = 0.09). No other significant associations were observed. Although substantial previous literature indicates that progesterone influences SRS, exogenous progesterone administration did not alter SRS here. Additional research is needed to elucidate alternative mechanisms involved in menstrual phase effects on SRS.

Lung Cancer in Women: A Modern Epidemic

Lung cancer in women is a modern epidemic and a major health crisis. Cigarette smoking remains the most important risk factor for lung cancer, and unfortunately smoking rates are either stabilized or continue to increase among women. Women may not be more susceptible to the carcinogenic effects of tobacco, but the biology of lung cancer differs between the sexes. This paper summarizes the biological sex differences in lung cancer, including molecular abnormalities, growth factor receptors, hormonal influences, DNA repair capacity, as well as differences in the histology and treatment outcomes of lung cancer in women.

Androgens are effective bronchodilators with anti-inflammatory properties: A potential alternative for asthma therapy

Changes in plasma androgen levels in asthmatic men may be linked to asthma severity, seemingly acting through nongenomic and genomic effects. Nongenomic effects include rapid relaxation of carbachol or antigenic challenge pre-contracted guinea pig airway smooth muscle (ASM) in vitro: testosterone (TES) blocks l-type voltage dependent Ca²⁺ channels, stored operated Ca²⁺ channels, inositol 1,4,5-trisphosphate receptors and promotes prostaglandin E₂ biosynthesis. In ASM at rest, TES lowers basal intracellular Ca²⁺ concentration and tension, maintaining a proper airway patency keeping steady smooth muscle tension and basal intracellular Ca²⁺ concentration at rest. Moreover, the bronchospasm in sensitized guinea-pigs was ablated by dehydroepiandrosterone (DHEA), a precursor of steroids, TES and its metabolites 5α- and 5β-dihydrotestosterone (DHT). On the other hand, genomic effects related to androgens' anti-inflammatory properties in asthma have been recently studied. Briefly, TES negatively regulates type 2 immune response sustained by CD4+ Th2 and group 2 innate lymphoid cells, diminishing allergic airway inflammation in males. Also, novel findings establish that TES decreases interleukin (IL)-17A protein expression produced by CD4+ Th17 cells and therefore neutrophilic airway inflammation. Clearly, DHEA, TES or its 5β-reduced metabolite that possesses minimal androgenic effect, might have potential therapeutic capacities in the treatment of severe asthma via mechanisms distinct from corticosteroid treatment.

The influence of hormone replacement therapy on lung cancer incidence and mortality

OBJECTIVE

Data regarding the effects of hormone replacement therapy (HRT) on non-small cell lung cancer (NSCLC) are mixed. We hypothesized HRT would have a protective benefit with reduced NSCLC incidence among women in a large, prospective cohort.

METHODS

We used data from the multicenter randomized Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (1993-2001). Participants were women aged 50 to 74 years followed prospectively for up to 13 years for cancer screening. The influence of HRT on the primary outcome of NSCLC incidence and secondary outcomes of all-cause and disease-specific mortality were assessed with Kaplan-Meier analysis and Cox proportional hazard models adjusting for covariates.

RESULTS

In the overall cohort of 75,587 women, 1147 women developed NSCLC after a median follow-up of 11.5 years. HRT use was characterized as 49.4% current users, 17.0% former users, and 33.6% never users. Increased age, smoking, comorbidities, and family history were associated with increased risk of NSCLC. On multivariable analysis, current HRT use was associated with reduced risk of NSCLC compared with never users (hazard ratio, 0.80; 95% confidence interval, 0.70-0.93; P = .009). HRT or oral contraception use was not associated with significant differences in all-cause mortality or disease-specific mortality.

CONCLUSIONS

These data represent among the largest prospective cohorts suggesting HRT use may have a protective effect on the development of NSCLC among women; the physiological basis of this effect merits further study; however, the results may influence discussion surrounding HRT use in women.

Tobacco Smoking Modifies the Association between Hormonal Factors and Lung Cancer Occurrence among Post-Menopausal Chinese Women

Inconsistent evidence has been reported on the role of female hormonal factors in the development of lung cancer. This population-based case–control study evaluated the main effect of menstrual/reproductive factors on the risk of lung cancer, and the effect modification by smoking status. Multivariable unconditional logistic regression models were applied adjusted for age, income, education, county of residence, body mass index, smoking status, pack-years of smoking, and family history of lung cancer. Among 680 lung cancer cases and 1,808 controls, later menopause (at >54 vs. <46 years old) was associated with increased risk of lung cancer (SBOR, semi-Bayes adjusted odds ratio = 1.61, 95% PI, posterior interval = 1.10–2.36). More pregnancies (2 or 3 vs. 0 or 1) was associated with decreased risk (SBOR = 0.71, 95% PI = 0.53, 0.95). Ever being a smoker and having two or fewer pregnancies in one's lifetime could jointly increase the odds of lung cancer (RERI, relative excess risk due to interaction = 1.71, 95% CI = 0.03, 3.38). An increased number of ovulatory cycles was associated with increased risk of lung cancer (SBOR for 13 ovulatory cycles = 1.02, 95% CI = 1.00+, 1.04).

Perioperative outcome of lung cancer surgery in women: results from a Spanish nationwide prospective cohort study

Background

To assess possible differences in the perioperative profile between men and women in lung cancer surgery.

Methods

A prospective cohort multicenter study was design, in which consecutive patients undergoing curative intent surgery for lung cancer in 24 Thoracic Services throughout Spain were included. Clinical features, tumor- and surgery-related data, postoperative complications, and mortality were recorded.

Results

There were 2,566 men and 741 women. Women were younger than men [mean (SD) age, 61.8 (10.8) vs. 66.5 (9.1) years, P<0.0001] and showed a more favorable preoperative characteristics, with significantly higher percentages of ECOG grade 0 and lower percentages of active smokers (28.4% vs. 33.9%; pack-years 18.8 vs. 26.9) and comorbidities [chronic obstructive pulmonary disease (COPD), diabetes, hypertension, cardiac disorders]. There were significant differences (P<0.001) in histological types and TNM stages with adenocarcinoma (70.1% vs. 46.4%) and IA stage (41.5% vs. 33.6%) more frequent in women. The use of VATS or thoracotomy was similar. The rate of pneumonectomy was higher in men (10.9%) than in women (5.1%) (P<0.001) but the distributions of other procedures were similar. Postoperative complications (pneumonitis, atelectasis, air leak, hemorrhage, fistula, empyema, wound dehiscence, and need of reintubation) were lower in women. Significant differences (P<0.0001) in the severity of postoperative complications (Clavien-Dindo classification) were also found, with higher percentages of grades I (51.6% vs. 43%) and II (37.5% vs. 33%) and lower percentages of grades III and IV among women. The mean length of hospital stay was 7.8 (7.1) days in men versus 6.3 (5.0) days in women, and the 30-day mortality rate 0.3% in women versus 2.9% in men (P<0.0001). The percentage of readmissions within 30 days after surgery was also higher in men (8.6% vs. 2.8%).

Conclusions

This multicenter nationwide study of lung cancer surgery with curative intent shows that the perioperative profile is better in women than in men.

Regional variation in lung and bronchus cancer survival in the US using mortality-to-incidence ratios

Despite major achievements aimed at reducing smoking over the last 50 years in the U.S., lung cancer remains the leading cause of cancer death. This study used mortality-to-incidence rate ratios (MIR) calculated from 2008 to 2012 National Cancer Institute data to highlight state-level variations in relative lung and bronchus cancer survival. In an ad hoc sensitivity analysis, we calculated a correlation between our state-level MIRs and five-year 1-survival rates for states reporting incident lung and bronchus cancer cases (2004-2008) to the Surveillance, Epidemiology, and End Results (SEER) Program database. Differences were observed in state lung and bronchus cancer MIRs, with the highest MIR values (poor relative survival) in southern states and the lowest MIRs primarily in northeastern states. In our sensitivity analysis, state-level MIRs were highly correlated with 1-survival rates. Examining regional variation in survival using MIRs can be a useful tool for identifying areas of health disparities and conducting surveillance activities.

Expression Analysis of Angiogenesis-Related Genes in Bulgarian Patients with Early-Stage Non-Small Cell Lung Cancer

Aims and background

Angiogenesis is a key process in the early stages of tumor development. In this study we aimed to evaluate the expression of a panel of angiogenesis-related genes in a group of Bulgarian patients with early-stage non-small cell lung cancer (NSCLC).

Methods and study design

We analyzed the expression of 84 genes associated with the angiogenic process in 12 NSCLCs of two histological subtypes: 7 adenocarcinomas and 5 squamous cell carcinomas. Eight peripheral nontumorous tissues were used as controls. We performed real-time PCR on pathway-specific gene arrays (SABiosciences).

Results

Our pilot study identified upregulated genes in early-stage NSCLC including growth factors (TGFA and EFNA3), the adhesion molecule THBS2, cytokines and chemokines (MDK, CXCL9, CXCL10), and the serine protease PLAU. Several genes showed downregulation including one growth factor (FIGF), the receptors for growth factors TEK and S1PR1 as well as adhesion molecules (COL4A3 and CDH5), the cytokine IL6, the matrix protein LEP and the transcription factor NOTCH4. The study demonstrated deregulated genes specific for the two histological subtypes including the transcription factor HAND2, which was overexpressed in squamous cell carcinomas but not adenocarcinomas.

Conclusions

Despite the limited number of patients, our results demonstrated the potential of angiogenesis-related genes as biomarkers in the early stages of NSCLC development. Free full text available at www.tumorionline.it

[Epidemiological Evolution of Lung Cancer in the South of Spain from 1990 to 2010]

Background

Changes in lung cancer has been characterized by the increase of cases among women and the increase in adenocarcinomas among other histological subtypes.

Methods

Descriptive analysis of cases diagnosed with lung cancer in Hospital Virgen de las Nieves (Spain) from 1990 to 2010, based on five variables (age, sex, smoking, histology and pathological anatomy). The study establishes associations between these variables and compares the results with the literature.

Results

2, 026 patients were diagnosed with lung cancer in this period; 1, 838 were males (90.7%) and 188 women (9.3%); 1, 892 patients (93.4%) were smokers or ex-smokers and 134 (6.6%) had never smoked; the most frequent non-small cell histology types were squamous cell carcinoma and adenocarcinoma and it was the most frequent neoplasia in women and were associated with a lower tobacco consumption.

Conclusion

The large majority of lung cancer cases is associated with a history of smoking tobacco and there are histopathological differences according to gender and cumulative tobacco smoke load.

RANK rewires energy homeostasis in lung cancer cells and drives primary lung cancer

Rao et al. report that RANK, the key regulator of osteoclastogenesis, is frequently expressed in primary lung tumors, and clonal genetic inactivation of RANK in mouse lung epithelial cells markedly impairs the progression of KRas^G12D-driven lung cancer. RANK rewires energy homeostasis in human and murine lung cancer cells and promotes expansion of lung cancer stem-like cells.

Lung cancer is the leading cause of cancer deaths. Besides smoking, epidemiological studies have linked female sex hormones to lung cancer in women; however, the underlying mechanisms remain unclear. Here we report that the receptor activator of nuclear factor-kB (RANK), the key regulator of osteoclastogenesis, is frequently expressed in primary lung tumors, an active RANK pathway correlates with decreased survival, and pharmacologic RANK inhibition reduces tumor growth in patient-derived lung cancer xenografts. Clonal genetic inactivation of KRas^G12D in mouse lung epithelial cells markedly impairs the progression of KRas^G12D-driven lung cancer, resulting in a significant survival advantage. Mechanistically, RANK rewires energy homeostasis in human and murine lung cancer cells and promotes expansion of lung cancer stem-like cells, which is blocked by inhibiting mitochondrial respiration. Our data also indicate survival differences in KRas^G12D-driven lung cancer between male and female mice, and we show that female sex hormones can promote lung cancer progression via the RANK pathway. These data uncover a direct role for RANK in lung cancer and may explain why female sex hormones accelerate lung cancer development. Inhibition of RANK using the approved drug denosumab may be a therapeutic drug candidate for primary lung cancer.

Different inhibitory potential of sex hormones on NNK detoxification in vitro: A possible explanation for gender-specific lung cancer risk

Smoking women are probably at a higher risk to develop lung cancer than men. Different explanations exist for these findings, a gender-specific impairment of tobacco carcinogen metabolism being one of them. In this study, we examined the inhibition of NNK reduction to NNAL, the first and most important detoxication step of this tobacco-specific carcinogen. It is mediated by different carbonyl reductases of the SDR (CBR1 and 11βHSD1) and AKR (AKR1B10, AKR1C1, AKR1C2 and AKR1C4) superfamilies. Inhibition constants of NNK reduction were determined with male (testosterone) and female (estradiol, progesterone) sex hormones and the contraceptives ethinylestradiol and drospirenone in A549 cells and with purified enzymes. Female sex hormones turned out to be stronger inhibitors than testosterone. The gestagen progesterone and its synthetic derivative drospirenone are the strongest inhibitors with Ki-values similar to hormone levels in pregnant women or women using hormonal contraceptives. Therefore, pregnancy or hormonal contraception may commit these women as high risk groups. The results of this study support the hypothesis that women bear a higher lung cancer risk when smoking because of female sex hormones acting as inhibitors of NNK detoxication.

Estrogen and cigarette sidestream smoke particulate matter exhibit ERα-dependent tumor-promoting effects in lung adenocarcinoma cells

Estrogen and secondhand smoke are key risk factors for nonsmoking female lung cancer patients who frequently have lung adenocarcinoma and show tumor estrogen receptor α (ERα) expression. We speculated that estrogen and secondhand smoke might cause harmful effects via ERα signaling. Our results showed that 17β-estradiol (E2), the primary form of endogenous estrogen, exacerbated proliferation, migration, and granzyme B resistance of lung adenocarcinoma cells in an ERα-dependent manner. Cigarette sidestream smoke particulate matter (CSSP), the major component of secondhand smoke, could activate ERα activity dose dependently in human lung adenocarcinoma cells. The estrogenic activity of CSSP was abolished by an ERα-selective antagonist. CSSP regulated the nuclear entry, phosphorylation, and turnover of ERα similarly to E2. Furthermore, CSSP enhanced E2-stimulated ERα activity and Ser118 phosphorylation even when ERα became saturated with E2. Activation of ERα by CSSP required GSK3β activity, but not involving polycyclic aromatic hydrocarbons, reactive oxygen species, calcium, epidermal growth factor receptor, and PI3K/Akt. Although CSSP possessed cytotoxicity, ERα-expressing cells grew and migrated faster than nonexpressing cells on recovery from CSSP exposure as observed in E2-pretreated cells. Knockdown of ERα by siRNA diminished E2- and CSSP-stimulated cell migration. Twenty-one genes, including SERPINB9, were identified to be upregulated by both E2 and CSSP via ERα. Increased SERPINB9 expression was accompanied with increased resistance to granzyme B-mediated apoptosis. This study demonstrates that estrogen has ERα-dependent tumor-promoting activity. CSSP acts like estrogen and shows a potential to enhance estrogen-induced ERα action.

Menstrual and reproductive factors and lung cancer risk: A pooled analysis from the international lung cancer consortium

Many clinical features of lung cancer are different in women and men. Sex steroid hormones exert effects in nonreproductive organs, such as the lungs. The association between menstrual and childbearing factors and the risk of lung cancer among women is still debated. We performed a pooled analysis of eight studies contributing to the International Lung Cancer Consortium (4,386 cases and 4,177 controls). Pooled associations between menstrual or reproductive factors and lung cancer were estimated using multivariable unconditional logistic regression. Subgroup analyses were done for menopause status, smoking habits and histology. We found no strong support for an association of age at menarche and at menopause with lung cancer, but peri/postmenopausal women were at higher risk compared to premenopausal (OR 1.47, 95% CI 1.11-1.93). Premenopausal women showed increased risks associated with parity (OR 1.74, 95% CI 1.03-2.93) and number of children (OR 2.88, 95% CI 1.21-6.93 for more than 3 children; p for trend 0.01) and decreased with breastfeeding (OR 0.54, 95% CI 0.30-0.98). In contrast, peri/postmenopausal subjects had ORs around unity for the same exposures. No major effect modification was exerted by smoking status or cancer histology. Menstrual and reproductive factors may play a role in the genesis of lung cancer, yet the mechanisms are unclear, and smoking remains the most important modifiable risk factor. More investigations in large well-designed studies are needed to confirm these findings and to clarify the underlying mechanisms of gender differences in lung cancer risk.

[Clinical Epidemiology and Histological Characteristics of 3,663 Lung Cancer Patients in Sichuan Province from 2008 to 2013]

背景与目的

肺癌作为全球男女性中致死率最高的肿瘤之一，严重威胁着人类的健康。近些年来，各个地区肺癌的发病率及死亡率也有逐年上升的趋势。本研究旨在分析四川地区肺癌患者的临床病理特征与流行趋势，了解肺癌地区与时间分布特点及差异。

方法

收集2008年-2013年四川大学华西医院就诊的四川地区肺癌患者，分析川中、川南、川北、川西的患者临床病理特征及流行趋势。

结果

纳入患者3, 663例（川中2, 378例，川南469例，川北584例，川西232例）。患者平均年龄59.6岁，各个地区患者平均年龄不同（P < 0.001），以川中最大，为61.0岁。患者以男性为主（68.4%），不同地区患者男性构成比存在差异（P=0.014），以川北最高，为73.3%。此外，各个地区的病理类型构成比也存在差异（P=0.014），腺癌和鳞癌都在川西构成比最高，分别为57.8%和30.2%，小细胞癌则在川北构成比最高（19.9%）。2013年腺癌与鳞癌构成比较2008年均有所降低，早期肺癌及淋巴结转移构成比有所上升。此外，不同地区肺癌患者3年生存率不同（P=0.021），以川西最低，仅为13.6%，可能与该地区采用姑息治疗患者比率高相关。

结论

近六年于我院就诊的四川地区肺癌患者以川中为主，男性多见，中老年为甚，腺癌居多，且腺癌和鳞癌的构成比与六年前相比均有下降，早期肺癌及淋巴结转移构成比上升。不同地区肺癌患者的平均年龄、男性构成比、病理类型及3年生存率均有差异。

Epidemiological changes in the histological subtypes of 35,018 non-small-cell lung cancer cases in Brazil

OBJECTIVES

Regarding the fatality rates stemming from various existing forms of cancers worldwide, lung cancer (LC) is ranked as the main cause of death amongst those who suffer from cancer. Although the epidemiological, clinical, and histological profile of patients with this type of cancer is largely unknown, Brazil has made tremendous efforts to generate data for supporting healthcare policies concerning lung cancer. Taking these factors into account, this study aims to analyse the epidemiological, clinical, and histological profiles of patients with non-small-cell lung cancer (NSCLC) in Brazil.

MATERIAL AND METHODS

For this study, a cross-sectional epidemiological study was conducted to nationally analyse patient's data within the cancer hospital registries found in the National Cancer Institute (INCA) and the São Paulo Cancer Foundation (FOSP) between 2000 and 2011.

RESULTS

A total of 35,018 patients diagnosed with NSCLC in Brazil between 2000 and 2011 were analysed. The analysis demonstrated the occurrence of an epidemiological shift, related to the most prevalent histological type of NSCLC in the study population from 2003. The shift resulted in a higher percentage of adenocarcinoma (43.3%) over squamous cell carcinoma (36.5%). Additionally, there was a significant increase in both the number of cases of LC in women and in the rates of patients diagnosed with metastatic disease.

CONCLUSION

The use of filtered cigarettes since the 60's and the increase in the number of LC cases in women, were one of the causes for the switch in the histological profile of NSCLC in Brazil. Consequently, adenocarcinoma is now the predominant type of cancer detected. Late diagnosis is a hallmark sign.

Pre-existing Pulmonary Diseases and Survival in Patients With Stage-dependent Lung Adenocarcinoma: A STROBE-compliant Article

Asthma, chronic obstructive pulmonary disease (COPD), and pulmonary tuberculosis (TB) are common lung diseases associated with lung cancer mortality. This study evaluated sex disparities in pre-existing pulmonary diseases and stage-dependent lung adenocarcinoma survival.Patients newly diagnosed with lung adenocarcinoma between 2003 and 2008 were identified using the National Health Insurance Research Database and Cancer Registry. Cases with lung adenocarcinoma were followed until the end of 2010. Survival curves were estimated by the Kaplan-Meier method. Cox proportional-hazard regression was used to calculate the hazard ratio (HR) of pre-existing asthma, COPD, and/or TB, and to estimate all-cause mortality risk in patients with different stages of lung adenocarcinoma.A total of 14,518 cases were identified with lung adenocarcinoma. Specifically, among men, the HRs for TB were 1.69 (95% confidence interval [CI], 1.10-2.58), 1.48 (95% CI, 1.14-1.93), and 1.27 (95% CI, 1.08-1.49) for individuals with stage I + II, III, and IV diseases, respectively. The HRs for asthma were 1.41 (95% CI, 1.00-1.99) in women with stage I + II and 1.14 (95% CI, 1.04-1.26) in men with stage IV disease. For pulmonary disease combinations in men, the HRs were 1.45 (95% CI, 1.12-1.89) for asthma + COPD + TB, 1.35 (95% CI, 1.12-1.63) for COPD + TB, 1.28 (95% CI, 1.01-1.63) for TB, and 1.15 (95%CI, 1.04-1.27) for asthma + COPD, respectively. For women with stage I + II disease, the HR was 6.94 (95% CI, 2.72-17.71) for asthma + COPD + TB.Coexistence of pre-existing pulmonary diseases increased mortality risk in men with adenocarcinoma. TB is at elevated risk of mortality among men with different stages of adenocarcinoma. Asthmatic women with early-stage adenocarcinoma had increased risk of mortality.

Genome-wide Gene-Asbestos Exposure Interaction Association Study Identifies a Common Susceptibility Variant on 22q13.31 Associated with Lung Cancer Risk

BACKGROUND

Occupational asbestos exposure has been found to increase lung cancer risk in epidemiologic studies.

METHODS

We conducted an asbestos exposure-gene interaction analyses among several Caucasian populations who were current or ex-smokers. The discovery phase included 833 Caucasian cases and 739 Caucasian controls, and used a genome-wide association study (GWAS) to identify single-nucleotide polymorphisms (SNP) with gene-asbestos interaction effects. The top ranked SNPs from the discovery phase were replicated within the International Lung and Cancer Consortium (ILCCO). First, in silico replication was conducted in those groups that had GWAS and asbestos exposure data, including 1,548 cases and 1,527 controls. This step was followed by de novo genotyping to replicate the results from the in silico replication, and included 1,539 cases and 1,761 controls. Multiple logistic regression was used to assess the SNP-asbestos exposure interaction effects on lung cancer risk.

RESULTS

We observed significantly increased lung cancer risk among MIRLET7BHG (MIRLET7B host gene located at 22q13.31) polymorphisms rs13053856, rs11090910, rs11703832, and rs12170325 heterozygous and homozygous variant allele(s) carriers (P < 5 × 10(-7) by likelihood ratio test; df = 1). Among the heterozygous and homozygous variant allele(s) carriers of polymorphisms rs13053856, rs11090910, rs11703832, and rs12170325, each unit increase in the natural log-transformed asbestos exposure score was associated with age-, sex-, smoking status, and center-adjusted ORs of 1.34 [95% confidence interval (CI), 1.18-1.51], 1.24 (95% CI, 1.14-1.35), 1.28 (95% CI, 1.17-1.40), and 1.26 (95% CI, 1.15-1.38), respectively, for lung cancer risk.

CONCLUSION

Our findings suggest that MIRLET7BHG polymorphisms may be important predictive markers for asbestos exposure-related lung cancer.

IMPACT

To our knowledge, our study is the first report using a systematic genome-wide analysis in combination with detailed asbestos exposure data and replication to evaluate asbestos-associated lung cancer risk.

Predictive Accuracy of the PanCan Lung Cancer Risk Prediction Model -External Validation based on CT from the Danish Lung Cancer Screening Trial

OBJECTIVES

Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models.

METHODS

From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination.

RESULTS

AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST.

CONCLUSIONS

High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor.

KEY POINTS

• High accuracy in logistic modelling for lung cancer risk stratification of nodules. • Lung cancer risk prediction is primarily based on size of pulmonary nodules. • Nodule spiculation, age and family history of lung cancer are significant predictors. • Sex does not appear to be a useful risk predictor.

Impact of coexisting pulmonary diseases on survival of patients with lung adenocarcinoma: a STROBE-compliant article

Asthma, chronic obstructive pulmonary disease (COPD), and pulmonary tuberculosis (TB) are common pulmonary diseases associated with lung cancer. Besides, smoking is more prevalent in Taiwanese men. This study evaluated gender disparities in coexisting pulmonary diseases on survival of patients with lung adenocarcinoma. Patients newly diagnosed with lung cancer between 2003 and 2008 were identified from Taiwan National Health Insurance Research Database. Cases with lung adenocarcinoma were further confirmed using the Cancer Registry Database and followed up until the end of 2010. Cox proportional hazard regression was used to calculate the hazard ratio (HR) of coexisting asthma, COPD, and/or TB to estimate all-cause mortality risk. During the study period, 13,399 cases of lung adenocarcinoma were identified. The HRs of adenocarcinoma in men and women were 1.20 (95% confidence interval [CI], 1.10-1.30) and 1.05 (95% CI, 0.95-1.16), respectively, for individuals with asthma, 1.32 (95% CI, 1.16-1.51) and 0.97 (95% CI, 0.89-1.05), respectively, for COPD, and 0.99 (95% CI, 0.93-1.06) and 1.06 (95% CI, 0.86-1.32), respectively, for individuals with TB. Specifically, among men with coexisting pulmonary diseases, the HRs were 1.63 (95% CI, 1.25-2.13), 1.31 (95% CI, 1.08-1.59), and 1.23 (95% CI, 1.11-1.36) for individuals with asthma + COPD + TB, asthma + COPD, and COPD + TB, respectively. However, there was no increase risk of mortality among women with coexisting pulmonary diseases. Coexisting pulmonary diseases are at an elevated risk of mortality among male patients with lung adenocarcinoma. Such patients deserve greater attention while undergoing cancer treatment.

Single nucleotide polymorphism in ATM gene, cooking oil fumes and lung adenocarcinoma susceptibility in Chinese female non-smokers: a case-control study

BACKGROUND

The ataxia-telangiectasia mutated (ATM) gene plays an important role in the DNA double-strand breaks repair pathway. Single nucleotide polymorphisms (SNPs) of DNA repair genes are suspected to influence the risk of lung cancer. This study aimed to investigate the association between the ATM -111G>A (rs189037) polymorphism, environmental risk factors and the risk of lung adenocarcinoma in Chinese female non-smokers.

METHODS

A hospital-based case-control study of 487 lung cancer patients and 516 matched cancer-free controls was conducted. Information concerning demographic and environmental risk factors was obtained for each case and control by a trained interviewer. After informed consent was obtained, 10 ml venous blood was collected from each subject for biomarker testing. Single nucleotide polymorphism was determined by using TaqMan method.

RESULTS

This study showed that the individuals with ATM rs189037 AA genotype were at an increased risk for lung adenocarcinoma compared with those carrying the GA or GG genotype (adjusted odds ratios (OR) 1.44, 95% confidence interval (CI) 1.02-2.02, P = 0.039). The stratified analysis suggested that increased risk associated with ATM rs189037 AA genotype in individuals who never or seldom were exposed to cooking oil fumes (adjusted OR 1.89, 95%CI 1.03-3.49, P = 0.040).

CONCLUSIONS

ATM rs189037 might be associated with the risk of lung adenocarcinoma in Chinese non-smoking females. Furthermore, ATM rs189037 AA genotype might be a risk factor of lung adenocarcinoma among female non-smokers without cooking oil fume exposure.

Telomere length in peripheral blood leukocytes and lung cancer risk: a large case-control study in Caucasians

Telomere dysfunction is a crucial event in malignant transformation and tumorigenesis. Telomere length in peripheral blood leukocytes has been associated with lung cancer risk, but the relationship has remained controversial. In this study, we investigated whether the association might be confounded by study of different histological subtypes of lung cancer. We measured relative telomere lengths in patients in a large case-control study of lung cancer and performed stratified analyses according to the two major histologic subtypes [adenocarcinoma and squamous cell carcinoma (SCC)]. Notably, patients with adenocarcinoma had longer telomeres than controls, whereas patients with SCC had shorter telomeres compared with controls. Long telomeres were associated with increased risk of adenocarcinoma, with the highest risk associated with female sex, younger age (<60 years), and lighter smoking (<30 pack-years). In contrast, long telomeres were protective against SCC, particularly in male patients. Our results extend the concept that telomere length affects risk of lung cancer in a manner that differs with histologic subtype.

The regulation of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumor promotion by estradiol in female A/J mice

Epidemiological studies indicate that women are at a higher risk developing lung cancer than men are. It is suggested that estrogen is one of the most important factors in lung cancer development in females. Additionally, cigarette smoke, and environmental pollutants, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), may play salient roles in female lung carcinogenesis. However, the mechanisms responsible for the interaction of these factors in the promotion of lung cancer are still poorly understood. The present study was designed to explore two ideas: first, the synergistic lung tumorigenic effects of 4-(methylnitrosamino)-1-(3-pyridyl)-butanol (NNK) combined with TCDD, 17β-estradiol (E2) or both through a long-term treatment experiment, and second, to identify early changes in the inflammatory and signaling pathways through short-term treatment experiments. The results indicate that A/J mice given E2 had strong effects in potentiating NNK-induced activation of MAPK signaling, NFκB, and COX-2 expression. In the long-term exposure model, E2 had a strong tumor promoting effect, whereas TCDD antagonized this effect in A/J mice. We conclude that treatment with NNK combined with either E2 or TCDD induces lung carcinogenesis and the promotion effects could be correlated with lung inflammation. E2 was shown to potentiate NNK-induced inflammation, cell proliferation, thereby leading to lung tumorigenesis.

Estrogen receptor beta and CXCR4/CXCL12 expression: differences by sex and hormonal status in lung adenocarcinoma

BACKGROUND AND AIMS

Studies have reported differences in lung cancer behavior between sex and hormonal status that suggest a role of estrogens and estrogen receptor beta (ERβ) in lung carcinogenesis. In some types of hormone-dependent cancer, estrogens may regulate CXCL12/CXCR4 expression through ERβ signaling. High expression of CXCL12/CXCR4 is associated with poor prognosis in lung cancer because it promotes tumor growth and metastasis. Therefore, in this study we investigated whether lung adenocarcinoma tissues from pre- and postmenopausal women and from men exhibit different ERβ, CXCR4/CXCL12 expression and whether this expression is associated with clinicopathological features.

METHODS

Sixty primary tumor samples of lung adenocarcinoma from pre- and postmenopausal women and from men were collected for this study. Thirty samples of healthy lung tissue adjacent to the tumor site were used as controls. ERβ and CXCL12/CXCR4 expression was analyzed by immunohistochemistry. Expression of these proteins was measured by digital image software and compared between sex and hormonal status.

RESULTS

Lung adenocarcinomas overexpressed ERβ, CXCR4 and CXCL12 compared to normal lung. Moreover, lung adenocarcinomas from premenopausal women exhibited higher signals for ERβ, CXCL12 and CXCR4 compared to postmenopausal women and to men, who showed lower signals for these proteins. A multivariate analysis revealed a strong association between the immunoreactivity level of ERβ, CXCL12/CXCR4 and both sex and hormonal status, but not with tumor stage and smoking.

CONCLUSION

These results demonstrated that ERβ and CXCL12/CXCR4 expression in lung adenocarcinoma depends on sex and hormonal status, which may partly explain the sex and hormonal differences in lung cancer behavior.

Gender-dependent effects of gonadectomy on lung carcinogenesis by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in female and male A/J mice

The present study was conducted to investigate the effects of gonadectomy on lung carcinogenesis in female and male mice, and to determine an association between sex hormone and lung carcinogenesis. Female and male A/J mice were divided into gonadectomized and unoperated control groups and all animals were treated intraperitoneally with 1 or 2 injections of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) at the dose of 2 mg/mouse. The mice were sacrificed 18 or 56 weeks after surgery. Serum levels of estradiol in females and testosterone in males were confirmed to be decreased by gonadectomy. Lung white nodules were detected in all mice of all groups. In the control groups of 18- and 56-week studies, the multiplicities of lung nodules in females were significantly greater than in males. In males in the 56-week study, the multiplicity of macroscopical lung nodules, bronchiolo-alveolar hyperplasias, adenomas and tumors (adenomas and adenocarcinomas) showed significant increase with castration. In females in the 18-week study, the multiplicity of adenomas decreased significantly by ovariectomy. Based on the results of the present study, female A/J mice were confirmed to be more susceptible to NNK-induced lung carcinogenesis than males. Furthermore, it was suggested that the process is inhibited by testosterone and accelerated by estradiol. These findings indicate the possibility that sex hormones play important roles in determining sex differences in lung carcinogenesis in the A/J mice initiated by NNK.

Smoking and smoking cessation in relation to the development of co-existing non-small cell lung cancer with chronic obstructive pulmonary disease

Previous studies have identified a mixed-phenotype of non-small cell lung cancer (NSCLC) with co-existing chronic obstructive pulmonary disease (COPD). Although NSCLC and COPD share a common risk factor in smoking, whether and how smoking may contribute to the coexistence of NSCLC with COPD (NSCLC-COPD) is unclear. Our study suggests that cigarette smoking is the major risk factor for the development of NSCLC-COPD, especially in females and among patients with squamous cell carcinoma subtype.

The joint effect of hOGG1, APE1, and ADPRT polymorphisms and cooking oil fumes on the risk of lung adenocarcinoma in Chinese non-smoking females

Background

The human 8-oxoguanine DNA glycosylase 1 (hOGG1), apurinic/apyrimidinic endonuclease 1 (APE1), and adenosine diphosphate ribosyl transferase (ADPRT) genes play an important role in the DNA base excision repair pathway. Single nucleotide polymorphisms (SNPs) in critical genes are suspected to be associated with the risk of lung cancer. This study aimed to identify the association between the polymorphisms of hOGG1 Ser326Cys, APE1 Asp148Glu, and ADPRT Val762Ala, and the risk of lung adenocarcinoma in the non-smoking female population, and investigated the interaction between genetic polymorphisms and environmental exposure in lung adenocarcinoma.

Methods

We performed a hospital-based case-control study, including 410 lung adenocarcinoma patients and 410 cancer-free hospital control subjects who were matched for age. Each case and control was interviewed to collect information by well-trained interviewers. A total of 10 ml of venous blood was collected for genotype testing. Three polymorphisms were analyzed by the polymerase chain reaction-restriction fragment length polymorphism technique.

Results

We found that individuals who were homozygous for the variant hOGG1 326Cys/Cys showed a significantly increased risk of lung adenocarcinoma (OR = 1.54; 95% CI: 1.01–2.36; P = 0.045). When the combined effect of variant alleles was analyzed, we found an increased OR of 1.89 (95% CI: 1.24–2.88, P = 0.003) for lung adenocarcinoma individuals with more than one homozygous variant allele. In stratified analyses, we found that the OR for the gene-environment interaction between Ser/Cys and Cys/Cys genotypes of hOGG1 codon 326 and cooking oil fumes for the risk of lung adenocarcinoma was 1.37 (95% CI: 0.77–2.44; P = 0.279) and 2.79 (95% CI: 1.50–5.18; P = 0.001), respectively.

Conclusions

The hOGG1 Ser326Cys polymorphism might be associated with the risk of lung adenocarcinoma in Chinese non-smoking females. Furthermore, there is a significant gene-environment association between cooking oil fumes and hOGG1 326 Cys/Cys genotype in lung adenocarcinoma among female non-smokers.

Cost disparities in lung cancer treatment by disability status, sex, and race

BACKGROUND

The recent literature contains numerous reports of disparities in the diagnosis, treatment, and outcomes of lung cancer across a growing list of population subgroups, including disability status. A common assumption is that disparities stem mainly from variations in the level and type of treatment resources available to specific subgroups. Few studies, however, have directly measured resource differentials. Since policy makers identify reducing health disparities as a critical priority, this study examined whether cumulative Medicare costs (resource consumption) for lung cancer treatment differ across eight patient subgroups defined by disability status, sex, and race.

HYPOTHESIS

Treatment disparities across the eight subgroups will be reflected in variations in the cumulative cost profiles of those subgroups, controlling for other plausible cost drivers. Failure to detect statistically significant differentials in these cost profiles implies that treatment disparities stem from factors other than access to, and utilization of, health care services.

METHODS

Linked SEER-Medicare data were used to construct cost profiles by service type and treatment phase for roughly 80,000 incident lung cancer cases in patients aged 45 to 85 years at diagnosis. Multiple regression models then tested for cost differentials across the eight subgroups, controlling for various patient and disease characteristics.

RESULTS

Significant cost differentials were detected, some unanticipated. Women tended to have higher treatment costs than men; they also had more favorable survivals. Nonwhites also tended to have higher treatment costs than whites, although they had significantly shorter survivals. On average, men with disabilities consumed the fewest treatment resources and had the shortest survivals. Mixed results were obtained for women with disabilities.

CONCLUSIONS

Among others, the findings suggest that reducing disparities will take more than just improving access to health care. Special attention must be paid to lung cancer patients with disabilities by both policy makers and clinicians.