Lung cancer incidence in never smokers

The role of human papillomavirus in nongenital cancers

Human papillomavirus (HPV), one of the most common sexually transmitted diseases worldwide, has an established role in the pathogenesis of genital malignancies such as cervical cancer. The virus has also been implicated in the oncogenesis of nongenital cancers including head and neck malignancies (specifically oropharyngeal cancers) as well as anal cancer. There is less clarity regarding its role in lung and esophageal cancers. Worldwide, the incidence and prevalence of HPV-associated oropharyngeal cancer has been increasing over time. These patients have improved outcomes compared with those with HPV-negative oropharyngeal cancers, and there is continued interest in designing treatments specifically for this HPV-positive subgroup. Clinicians continue to gain an understanding of HPV in anal cancers and the risk factors associated with infection and progression to malignancy. This has potential implications for the eventual screening of high-risk groups. While HPV vaccination is currently approved for the prevention of cervical cancer, it also has potential in the prevention of all HPV-associated malignancies. In this review, current understanding of the role of HPV in nongenital cancers is discussed, as well as future implications for treatment and prevention.

Lung cancer in women

Recent biological advances in tumor research provide clear evidence that lung cancer in females is different from that in males. These differences appear to have a direct impact on the clinical presentation, histology, and outcomes of lung cancer. Women are more likely to present with lung adenocarcinoma, tend to receive a diagnosis at an earlier age, and are more likely to be diagnosed with localized disease. Women may also be more predisposed to molecular aberrations resulting from the carcinogenic effects of tobacco, but do not appear to be more susceptible than men to developing lung cancer. The gender differences found in female lung cancer make it mandatory that gender stratification is used in clinical trials in order to improve the survival rates of patients with lung cancer.

EGFR polymorphisms, hormone replacement therapy and lung adenocarcinoma risk: analysis from a genome-wide association study in never-smoking women

Hormone replacement therapy (HRT) and epidermal growth factor receptor (EGFR) single nucleotide polymorphisms (SNPs) have been reported as risk factors for lung cancer in never smokers. We investigate the interaction of EGFR SNPs and HRT for lung adenocarcinoma risk in never-smoking women. This study included 532 never-smoking female lung adenocarcinoma patients and 532 controls, with EGFR SNPs retrieved from a genome-wide association study. The associations of EGFR SNPs with the lung adenocarcinoma risk were estimated by multivariate-adjusted logistic regression. The Haploview program was used to select tagged EGFR SNPs interacted with HRT and construct haplotype blocks. The Benjamini and Hochberg method was used to reduce the multiple testing effects. Among 84 EGFR SNPs retrieved, 11 tagging EGFR SNPs showed an interaction with HRT and lung adenocarcinoma risk, which were mostly located near the tyrosine kinase domain. Eight of the tagged SNPs were in two haplotype blocks. The interactions between HRT and numbers of protective EGFR SNP genotypes are significant in both blocks (P for interaction = 0.0004 and 0.0032, respectively). A trend of decrease in lung adenocarcinoma risk was found in subjects with HRT harboring an increasing number of protective EGFR SNP genotypes in both blocks (P = 0.0032 and 0.0046, respectively). In conclusion, HRT use may modify the association of EGFR SNPs with lung adenocarcinoma risk. The EGFR SNPs have a cumulative effect on decreasing lung adenocarcinoma risk in never-smoking women with HRT use.

The role of estrogen, progesterone and aromatase in human non-small-cell lung cancer

Lung cancer is the leading cause of cancer-related deaths in both men and women worldwide. Despite advances in treatment, patients have few effective therapeutic options and survival rates remain low. Emerging evidence suggests that the hormones estrogen and progesterone play a key role in the progression of non-small-cell lung cancer (NSCLC). The aromatase enzyme, which is responsible for a key step in estrogen biosynthesis, elicits higher levels of estrogen in lung tumors as well as in metastases compared with nonmalignant tissues. Thus, aromatase may prove to be a key predictive biomarker for treatment of NSCLC. Epidemiologic and preclinical data show estrogens play a critical role in lung tumor development and progression. Two estrogen receptors, α and β, are expressed in normal and in cancerous lung epithelium, and estrogen promotes gene transcription that stimulates cell proliferation and inhibits cell death. Furthermore, expression of both forms of estrogen receptor, progesterone receptor and aromatase in NSCLC specimens has been correlated with worse clinical outcomes. Combination therapies that include estrogen receptor downregulators and aromatase inhibitors are currently being assessed in Phase I-II clinical trials among patients with advanced NSCLC. Results will help guide future lung cancer management decisions, with a goal of achieving more effective and less toxic treatments for patients.

Occupational and environmental causes of lung cancer

Because tobacco smoking is a potent carcinogen, secondary causes of lung cancer are often diminished in perceived importance. The goal of this review is to describe the occurrence and recent findings of the 27 agents currently listed by the International Agency for Research on Cancer (IARC) as lung carcinogens. The IARC's updated assessments of lung carcinogens provide a long-overdue resource for consensus opinions on the carcinogenic potential of various agents. Supplementary new information, with a focus on analytic epidemiologic studies that has become available since IARC's most recent evaluation, are also discussed.

Lung cancer epidemiology, risk factors, and prevention

The greatest risk by far for developing lung cancer is cigarette smoking, but age, radon exposure, environmental pollution, occupational exposures, gender, race, and pre-existing lung disease also are important contributors. However, not all people with these risk factors develop lung cancer, and some without any known risk factor do, indicating the importance of genetic influences. Future advances in understanding and treating lung cancer will be based on genetic analysis. The most effective preventive measure is to never start or to stop cigarette smoking.

Estrogen signaling in lung cancer: an opportunity for novel therapy

Lung cancer is the leading cause of cancer death in U.S. and represents a major public health burden. Epidemiologic data have suggested that lung cancer in women may possess different biological characteristics compared to men, as evidenced by a higher proportion of never-smokers among women with lung cancer. Emerging data indicate that female hormones such as estrogen and progesterone play a significant role in lung carcinogenesis. It has been reported that estrogen and progesterone receptors are expressed in lung cancer cell lines as well as in patient-derived tumors. Hormone related risk factors such as hormone replacement therapy have been implicated in lung carcinogenesis and several preclinical studies show activity of anti-estrogen therapy in lung cancer. In this review, we summarize the emerging evidence for the role of reproductive hormones in lung cancer and implications for lung cancer therapy.

EGFR overexpression in canine primary lung cancer: pathogenetic implications and impact on survival

This study reports the main clinicopathological features of primary lung cancer (PLC) in 37 dogs, with special regard to the pathogenetic and prognostic role of epidermal growth factor receptor (EGFR) overexpression. For each case the following characteristics were evaluated: tumour-node-metastasis (TNM) stage, tumour histotype, histological grade, mitotic activity and immunohistochemical expression of EGFR. In samples with available normal lung tissue, the amount of background anthracosis was also measured by image analysis. In 27 tumours (73%) a variable number of cells (20-100%) stained positively for EGFR. The proportion of EGFR-positive tumours was significantly higher in cases with background anthracosis, and the amount of anthracosis was correlated with the percentage of positive tumour cells. Additionally, a trend towards shortened survival for the high EGFR group was observed. These findings suggest an involvement of EGFR signalling pathway in canine PLC, a negative prognostic significance of protein overexpression and its potential implication in air pollution carcinogenesis.

Chapter 6: Lung cancer in never smokers: epidemiology and risk prediction models

In this chapter we review the epidemiology of lung cancer incidence and mortality among never smokers/nonsmokers and describe the never smoker lung cancer risk models used by the Cancer Intervention and Surveillance Network (CISNET) modelers. Our review focuses on those influences likely to have measurable population impact on never smoker risk, such as secondhand smoke, even though the individual-level impact may be small. Occupational exposures may also contribute importantly to the population attributable risk of lung cancer. We examine the following risk factors in this chapter: age, environmental tobacco smoke, cooking fumes, ionizing radiation including radon gas, inherited genetic susceptibility, selected occupational exposures, preexisting lung disease, and oncogenic viruses. We also compare the prevalence of never smokers between the three CISNET smoking scenarios and present the corresponding lung cancer mortality estimates among never smokers as predicted by a typical CISNET model.

Similar DNA methylation pattern in lung tumours from smokers and never-smokers with second-hand tobacco smoke exposure

Tobacco smoke causes lung cancer in smokers and in never-smokers exposed to second-hand tobacco smoke (SHS). Nonetheless, molecular mechanisms of lung cancer in SHS-exposed never-smokers are still elusive. We studied lung cancers from current smokers (n = 109), former smokers (n = 56) and never-smokers (n = 47) for promoter hypermethylation of five tumour suppressor genes--p16, RARB, RASSF1, MGMT and DAPK1--using methylation-specific polymerase chain reaction. Lung tumours from ever-smokers suggested an increased risk of p16 hypermethylation as compared to never-smokers (P = 0.073), with former smokers having the highest frequency of p16 hypermethylation (P = 0.044 versus current smokers and P = 0.009 versus never-smokers). In the never-smoking group, p16 hypermethylation was seen in lung tumours from SHS-exposed individuals (4/33; 12%) but in none of the non-exposed individuals (0/9). The overall occurrence of hypermethylation (measured both as methylation index and as number of genes affected) was similar in those ever exposed to tobacco smoke (smokers, SHS-exposed never-smokers) and differed from non-exposed never-smokers. In multivariate analysis, p16 hypermethylation was more prevalent in lung tumours from male than female patients (P = 0.018) and in squamous cell carcinomas than in adenocarcinomas (P = 0.025). Occurrence of TP53 mutation in the tumour was associated with hypermethylation of at least one gene (P = 0.027). In all, our data suggest that promoter hypermethylation pattern in SHS-exposed never-smokers resembles that observed in smokers. Association between TP53 mutation, a hallmark of smokers' lung cancer, and methylation of one or more of the lung cancer-related genes studied, provides further evidence for common tobacco smoke-related origin for both types of molecular alterations.

A decade of advances in treatment for advanced non-small cell lung cancer

The last decade has heralded a paradigm shift in the evaluation and treatment of advanced non-small cell lung cancer (NSCLC). No longer are patients with NSCLC considered a homogeneous population treated in the same way; rather, clinical characteristics, histology, and an expanding array of molecular markers are increasingly being used to individualize therapy. Both histology and tumor epidermal growth factor receptor mutational status currently have firmly established roles in determining initial and salvage therapy for advanced NSCLC. Several other biomarkers are the focus of ongoing prospective randomized clinical trials customizing both traditional chemotherapy and newer molecularly targeted agents.

At the crossroads: EGFR and PTHrP signaling in cancer-mediated diseases of bone

The epidermal growth factor receptor is a well-established cancer therapeutic target due to its stimulation of proliferation, motility, and resistance to apoptosis. Recently, additional roles for the receptor have been identified in growth of metastases. Similar to development, metastatic spread requires signaling interactions between epithelial-derived tumor cells and mesenchymal derivatives of the microenvironment. This necessitates reactivation of developmental signaling molecules, including the hypercalcemia factor parathyroid hormone-related protein. This review covers the variations of epidermal growth factor receptor signaling in cancers that produce bone metastases, regulation of parathyroid hormone-related protein, and evidence that the two molecules drive cancer-mediated diseases of bone.

Role of hormone receptor expression in patients with advanced-stage lung cancer treated with chemotherapy

BACKGROUND

Evidence that supports a role for hormonal status in lung cancer has been inconsistently reported and is still unclear. We retrospectively assessed the potential correlation between sex-linked hormone receptor expression and the clinical outcome of patients with advanced-stage lung cancer treated with chemotherapy.

PATIENTS AND METHODS

Based on tissue availability, 130 consecutive patients diagnosed at San Luigi Hospital from January 2008 to June 2010 were collected, including 24 small-cell lung cancer, 57 adenocarcinomas, 34 squamous cell carcinomas, 5 large-cell carcinomas, and 10 non-small-cell lung cancer-not otherwise specified. The immunohistochemical expression of estrogen receptors (ER-α and ER-β) and progesterone receptor, aromatase, epidermal growth factor receptor (EGFR), and excision repair cross-complementing 1 (ERCC1) was assessed.

RESULTS

ER-β nuclear expression was higher than ER-α and progesterone receptor, whose expression was null or weak (mainly in women). ER-β expression was significantly higher in patients with metastatic disease compared with all other disease stages (P = .02). EGFR expression was strongly correlated with non-small-cell lung cancer histology, being higher in squamous types and stage related. In men, aromatase positive cases had a worse outcome (P = .03) as well as in men with non-small-cell lung cancer and high ER-β expression. In the latter group, the combined aromatase negative and/or low ER-β expression and low ERCC1 and/or low ER-β expression showed a better outcome (P = .026; P = .03, respectively).

CONCLUSION

In patients with advanced-stage lung cancer treated with chemotherapy, the prognostic and predictive role of sex-linked hormone receptor expression, if any, is of borderline significance and is restricted to selected subgroups of patients.

Professional exposure to goats increases the risk of pneumonic-type lung adenocarcinoma: results of the IFCT-0504-Epidemio study

Pneumonic-type lung adenocarcinoma (P-ADC) represents a distinct subset of lung cancer with specific clinical, radiological, and pathological features. Given the weak association with tobacco-smoking and the striking similarities with jaagsiekte sheep retrovirus (JSRV)-induced ovine pulmonary adenocarcinoma, it has been suggested that a zoonotic viral agent infecting pulmonary cells may predispose to P-ADC in humans. Our objective was to explore whether exposure to domestic small ruminants may represent a risk factor for P-ADC. We performed a multicenter case-control study recruiting patients with P-ADC as cases and patients with non-P-ADC non-small cell lung cancer as controls. A dedicated 356-item questionnaire was built to evaluate exposure to livestock. A total of 44 cases and 132 controls were included. At multivariate analysis, P-ADC was significantly more associated with female gender (Odds-ratio (OR) = 3.23, 95% confidence interval (CI): 1.32–7.87, p = 0.010), never- smoker status (OR = 3.57, 95% CI: 1.27–10.00, p = 0.015), personal history of extra-thoracic cancer before P-ADC diagnosis (OR = 3.43, 95% CI: 1.10–10.72, p = 0.034), and professional exposure to goats (OR = 5.09, 95% CI: 1.05–24.69, p = 0.043), as compared to other subtypes of lung cancer. This case-control suggests a link between professional exposure to goats and P-ADC, and prompts for further epidemiological evaluation of potential environmental risk factors for P-ADC.

Heritability of radiation response in lung cancer families

Radiation sensitivity is assumed to be a cancer susceptibility factor due to impaired DNA damage signalling and repair. Relevant genetic factors may also determine the observed familial aggregation of early onset lung cancer. We investigated the heritability of radiation sensitivity in families of 177 Caucasian cases of early onset lung cancer. In total 798 individuals were characterized for their radiation-induced DNA damage response. DNA damage analysis was performed by alkaline comet assay before and after in vitro irradiation of isolated lymphocytes. The cells were exposed to a dose of 4 Gy and allowed to repair induced DNA-damage up to 60 minutes. The primary outcome parameter Olive Tail Moment was the basis for heritability estimates. Heritability was highest for basal damage (without irradiation) 70% (95%-CI: 51%-88%) and initial damage (directly after irradiation) 65% (95%-CI: 47%-83%) and decreased to 20%-48% for the residual damage after different repair times. Hence our study supports the hypothesis that genomic instability represented by the basal DNA damage as well as radiation induced and repaired damage is highly heritable. Genes influencing genome instability and DNA repair are therefore of major interest for the etiology of lung cancer in the young. The comet assay represents a proper tool to investigate heritability of the radiation sensitive phenotype. Our results are in good agreement with other mutagen sensitivity assays.

Female reproductive factors, gene polymorphisms in the estrogen metabolism pathway, and risk of lung cancer in Chinese women

The authors examined relations between reproductive factors and 5 estrogen pathway gene polymorphisms (CYP17 rs743572, CYP19A1 rs10046, ERβ rs1256049, ERβ rs4986938, and COMT rs4680) among 702 Singapore Chinese female lung cancer cases and 1,578 hospital controls, of whom 433 cases (61.7%) and 1,375 controls (87.1%) were never smokers. Parity (per child, odds ratio (OR) = 0.92, 95% confidence interval (CI): 0.87, 0.97) and menstrual cycle length (for ≥30 days vs. <30 days, OR = 0.50, 95% CI: 0.32, 0.80) were inversely associated with lung cancer in never smokers, while age at first birth (for ages 21-25, 26-30, and ≥31 years vs. ≤20 years, ORs were 1.54, 2.17, and 1.30, respectively), age at menopause (for ages 49-51 and ≥52 years vs. ≤48 years, ORs were 1.37 and 1.59; P(trend) = 0.003), and reproductive period (for 31-33, 34-36, 37-39, and ≥40 years vs. ≤30 years, ORs were 1.06, 1.25, 1.45, and 1.47; P(trend) = 0.026) were positively associated. Among smokers, parity was inversely associated with lung cancer, but there was no association with other reproductive factors. The COMT rs4680 A allele was positively associated with lung cancer in never smokers (for G/A or A/A vs. G/G, OR = 1.46, 95% CI: 1.12, 1.90) but not in ever smokers. No associations were seen with other polymorphisms. These results support a risk-enhancing role of estrogens in lung carcinogenesis among never smokers.

Pulmonary adenocarcinoma: a renewed entity in 2011

Lung cancer, of which non-small-cell lung cancer comprises the majority, is the leading cause of cancer-related deaths in the United States and worldwide. Lung adenocarcinomas are a major subtype of non-small-cell lung cancers, are increasing in incidence globally in both males and females and in smokers and non-smokers, and are the cause for almost 50% of deaths attributable to lung cancer. Lung adenocarcinoma is a tumour with complex biology that we have recently started to understand with the advent of various histological, transcriptomic, genomic and proteomic technologies. However, the histological and molecular pathogenesis of this malignancy is still largely unknown. This review will describe advances in the molecular pathology of lung adenocarcinoma with emphasis on genomics and DNA alterations of this disease. Moreover, the review will discuss recognized lung adenocarcinoma preneoplastic lesions and current concepts of the early pathogenesis and progression of the disease. We will also portray the field cancerization phenomenon and lineage-specific oncogene expression pattern in lung cancer and how both remerging concepts can be exploited to increase our understanding of lung adenocarcinoma pathogenesis for subsequent development of biomarkers for early detection of adenocarcinomas and possibly personalized prevention.

Asthma and lung cancer risk: a systematic investigation by the International Lung Cancer Consortium

Asthma has been hypothesized to be associated with lung cancer (LC) risk. We conducted a pooled analysis of 16 studies in the International Lung Cancer Consortium (ILCCO) to quantitatively assess this association and compared the results with 36 previously published studies. In total, information from 585 444 individuals was used. Study-specific measures were combined using random effects models. A meta-regression and subgroup meta-analyses were performed to identify sources of heterogeneity. The overall LC relative risk (RR) associated with asthma was 1.28 [95% confidence intervals (CIs) = 1.16-1.41] but with large heterogeneity (I(2) = 73%, P < 0.001) between studies. Among ILCCO studies, an increased risk was found for squamous cell (RR = 1.69, 95%, CI = 1.26-2.26) and for small-cell carcinoma (RR = 1.71, 95% CI = 0.99-2.95) but was weaker for adenocarcinoma (RR = 1.09, 95% CI = 0.88-1.36). The increased LC risk was strongest in the 2 years after asthma diagnosis (RR = 2.13, 95% CI = 1.09-4.17) but subjects diagnosed with asthma over 10 years prior had no or little increased LC risk (RR = 1.10, 95% CI = 0.94-1.30). Because the increased incidence of LC was chiefly observed in small cell and squamous cell lung carcinomas, primarily within 2 years of asthma diagnosis and because the association was weak among never smokers, we conclude that the association may not reflect a causal effect of asthma on the risk of LC.

GPC5 rs2352028 polymorphism and risk of lung cancer in Han Chinese

rs2352028 in GPC5 has been reported to be associated with the risk of lung cancer in never-smokers. We performed a replication study in 1,045 lung cancer patients and 1,094 controls of Han Chinese origin. We found no association between rs2352028 and lung cancer/adenocarcinoma in never-smokers, but a p value of .04 (under the recessive model) was obtained between this SNP and overall lung cancer/adenocarcinoma. Our data and a recent meta-analysis suspected the possibility of rs2352028 being a risk variant of lung cancer risk in never-smokers. Our findings suggested that rs2352028 might confer a slight risk to lung cancer/adenocarcinoma.

Epidemiology and management of common pulmonary diseases in older persons

Pulmonary disease prevalence increases with age and contributes to morbidity and mortality in older patients. Dyspnea in older patients is often ascribed to multiple etiologies such as medical comorbidities and deconditioning. Common pulmonary disorders are frequently overlooked as contributors to dyspnea in older patients. In addition to negative impacts on morbidity and mortality, quality of life is reduced in older patients with uncontrolled, undertreated pulmonary symptoms. The purpose of this review is to discuss the epidemiology of common pulmonary diseases, namely pneumonia, chronic obstructive pulmonary disease, asthma, lung cancer, and idiopathic pulmonary fibrosis in older patients. We will review common clinical presentations for these diseases and highlight differences between younger and older patients. We will also briefly discuss risk factors, treatment, and mortality associated with these diseases. Finally, we will address the relationship between comorbidities, pulmonary symptoms, and quality of life in older patients with pulmonary diseases.

Lung cancer: epidemiology, etiology, and prevention

Lung cancer is the leading cause of cancer death in the United States and around the world. A vast majority of lung cancer deaths are attributable to cigarette smoking, and curbing the rates of cigarette smoking is imperative. Understanding the epidemiology and causal factors of lung cancer can provide additional foundation for disease prevention. This article focuses on modifiable risk factors, including tobacco smoking, occupational carcinogens, diet, and ionizing radiation. It also discusses briefly the molecular and genetic aspects of lung carcinogenesis.

Lung cancer: epidemiology, etiology, and prevention

Lung cancer is the leading cause of cancer death in the United States and around the world. A vast majority of lung cancer deaths are attributable to cigarette smoking, and curbing the rates of cigarette smoking is imperative. Understanding the epidemiology and causal factors of lung cancer can provide additional foundation for disease prevention. This article focuses on modifiable risk factors, including tobacco smoking, occupational carcinogens, diet, and ionizing radiation. It also discusses briefly the molecular and genetic aspects of lung carcinogenesis.

Difference in survival and prognostic factors between smokers and never-smokers with advanced non-small-cell lung cancer

BACKGROUND

Our aims were to investigate whether the association between smoking and survival is significant when adjusted for prognostic factors including use of epidermal growth factor tyrosine kinase inhibitors and the Glasgow Prognostic Score, an established score for inflammation, and to explore prognostic factors.

METHODS

We analyzed 244 patients with stage IIIB or IV non-small-cell lung cancer in a registry, including only chemotherapy-receiving outpatients with performance status zero.

RESULTS

Of 244 patients, 170 had died and the median follow-up time for the 74 surviving patients was 12.0 months. In multivariate Cox regression, smoker (hazard ratio compared to never-smoker: 1.67, P < 0.01), stage IV (hazard ratio compared to IIIB: 1.72, P < 0.01), and elevated C-reactive protein level (hazard ratio per 1 mg/dL increase: 1.08, P < 0.01) were significantly associated with shorter survival. The association between survival and smoking was significant, even after adjustment for the Glasgow Prognostic Score and regimens of chemotherapy (hazard ratio: 1.72, P = 0.02). In never-smokers, increased neutrophils were a major determinant of shorter survival and the interaction test between smoking and neutrophils was significant (hazard ratio per 1,000/mm(3) increase for smokers: 1.01; hazard ratio per 1,000/mm(3) increase for never-smokers: 1.44, P for interaction <0.01).

CONCLUSIONS

Known factors including treatment response or inflammatory process are not responsible for the fact that advanced non-small-cell lung cancer patients without any history of smoking have better survival than those who have smoked.

Sex steroid receptors in human lung diseases

Several epidemiological studies have reported that gender differences exist in clinical and biological manifestations of human lung diseases. In particular, women are far more likely to develop both neoplastic and non-neoplastic lung diseases than men. This gender difference above suggests that sex steroid may be involved in the pathogenesis of various lung diseases. These sex steroids mediate their effects through sex steroid receptors including estrogen receptors (ER) i.e. ERα and ERβ progesterone receptors (PR) i.e. PR-A and PR-B and androgen receptors (ARs), all of which have been reported to be expressed in lung tissue. Therefore it becomes important to clarify the potential roles of sex steroid receptor in both neoplastic and non-neoplastic lung diseases toward improved treatment options for the patients. In this review, we summarized a number of studies in humans and experimental animals that have identified possible roles of sex steroids in respiratory physiology and pathology.

ALK and NSCLC: Targeted therapy with ALK inhibitors

For many years treatment for advanced or metastatic non-small cell lung cancer (NSCLC) has employed chemotherapy regimens for patient care, with limited effect. Five-year survival rates for these patients are not encouraging. However, for a subgroup of these patients, there have been radical changes over recent years. Our understanding of the basic pathology behind NSCLC at the molecular level has offered up a host of new molecularly targeted therapies, which are revolutionizing this area of cancer care. Results from recent clinical trials provide hope for NSCLC patients harboring oncogenic translocations involving the anaplastic lymphoma kinase (ALK) receptor tyrosine kinase. Just as inhibition of the breakpoint cluster region-ABL complex has changed the face of chronic myeloid leukemia diagnosis, oncogenic ALK fusions offer a step forward in the diagnosis and treatment of ALK-positive NSCLC. This article discusses the current knowledge and potential implications concerning ALK inhibitors and NSCLC.

XPC mRNA level may predict relapse in never-smokers with non-small cell lung cancers

BACKGROUND

Disease recurrence and distant metastasis are the major causes of death in resected non-small cell lung cancer (NSCLC). The prognostic marker for never-smokers with this disease remains to be identified. To improve patient outcome, establishing an adjacent molecular marker to predict relapse of NSCLC in never-smokers is needed.

METHODS

Three hundred two lung tumors from NSCLC patients and normal lung tissues from 68 noncancer subjects were enrolled to evaluate XPC (xeroderma pigmentosum group C) mRNA expression by quantitative real-time reverse transcriptase polymerase chain reaction. Receiver operating characteristic curve analysis was used to search for a feasible cutoff point of XPC mRNA levels for predicting recurrence-free survival. Of the 326 patients, 214 were confirmed as only receiving surgical resection. Kaplan-Meier and multivariate Cox regression analysis were used to assess the prognostic value of XPC mRNA level in lung tumors from patients who only received surgical resection.

RESULTS

Receiver operating characteristic curve analysis indicated 30.28 as a cutoff point, and thus 150 and 64 tumors with low- and high-XPC mRNA expression were categorized in this study population. Low-XPC mRNA appeared with more frequency in never-smokers and in late-stage (stage II-III) disease than smokers and early-stage disease (stage I). Kaplan-Meier analysis indicated that patients with low-XPC mRNA had shorter recurrence-free survival than that found in never-smokers (P = 0.002), but not in smokers (P = 0.296). Cox regression analysis further revealed that low-XPC mRNA may independently predict relapse in lung cancer of never-smokers (hazard ratio 2.34, 95% confidence interval 1.21-4.51, P = 0.011).

CONCLUSIONS

Low-XPC mRNA may predict relapse in lung cancer patients who are never-smokers.

Aromatase in human lung carcinoma

Lung cancer is the leading cause of cancer mortality in both women and men worldwide but gender differences exist in their clinical and biological manifestations. In particular, among life time non-smoker, female are far more likely to develop lung carcinoma than male. Recent studies demonstrated that estrogens are synthesized in situ in both male and female lung cancers through aromatase, suggesting that sex steroid may contribute to the pathogenesis and development of lung carcinoma. In addition, human lung carcinomas have been recently demonstrated to be frequently associated with expression of estrogen receptors in both male and female patients and a lower expression of aromatase was reported to be associated with better prognosis. Preclinical studies further demonstrated that aromatase inhibitor (AI) suppressed the lung tumor growth both in vitro and in vivo. These findings all suggest a potential role of intratumoral aromatase in biological behavior of non-small cell lung cancer (NSCLC), the most common form of human lung malignancy. Therefore, AIs may become viable therapeutic options for disease management in NSCLC patients but further studies are definitely required to obtain a better understanding of the potential roles of intratumoral aromatase expression as a predictive biomarker for clinical outcome in these NSCLC patients.

Magnetic resonance imaging for lung cancer detection: experience in a population of more than 10,000 healthy individuals

BACKGROUND

Recent refinements of lung MRI techniques have reduced the examination time and improved diagnostic sensitivity and specificity. We conducted a study to assess the feasibility of MRI for the detection of primary lung cancer in asymptomatic individuals.

METHODS

A retrospective chart review was performed on images of lung parenchyma, which were extracted from whole-body MRI examinations between October 2000 and December 2007. 11,766 consecutive healthy individuals (mean age, 50.4 years; 56.8% male) were scanned using one of two 1.5-T scanners (Sonata and Sonata Maestro, Siemens Medical Solutions, Erlangen, Germany). The standard protocol included a quick whole-lung survey with T2-weighted 2-dimensional half Fourier acquisition single shot turbo spin echo (HASTE) and 3-dimensional volumetric interpolated breath-hold examination (VIBE). Total examination time was less than 10 minutes, and scanning time was only 5 minutes. Prompt referrals and follow-ups were arranged in cases of suspicious lung nodules.

RESULTS

A total of 559 individuals (4.8%) had suspicious lung nodules. A total of 49 primary lung cancers were diagnosed in 46 individuals: 41 prevalence cancers and 8 incidence cancers. The overall detection rate of primary lung cancers was 0.4%. For smokers aged 51 to 70 years, the detection rate was 1.4%. TNM stage I disease accounted for 37 (75.5%). The mean size of detected lung cancers was 1.98 cm (median, 1.5 cm; range, 0.5-8.2 cm). The most histological types were adenocarcinoma in 38 (77.6%).

CONCLUSION

Rapid zero-dose MRI can be used for lung cancer detection in a healthy population.

Influence of polymorphisms in MTHFR 677 C→T, TYMS 3R→2R and MTR 2756 A→G on NSCLC risk and response to platinum-based chemotherapy in advanced NSCLC

AIMS

Genetic factors may contribute to individual differences in cancer susceptibility, drug efficacy and toxicity. This study was designed to investigate the effects of the polymorphisms of methylenetetrahydrofolate reductase 677 C→T (MTHFR 677 C→T), thymidylate synthase (TYMS 3R→2R),and methionine synthase 2756 A→G (MTR 2756 A→G) on the risk of lung cancer and response to platinum-based chemotherapy in advanced non-small-cell lung cancer (NSCLC).

MATERIALS & METHODS

We conducted a case-control study involving 438 NSCLC cases (including 101 follow-up cases) and 641 healthy controls in North China.

RESULTS & CONCLUSION

Using a genetic model analysis, the polymorphism MTHFR 677 C→T showed a significantly increased risk for NSCLC in women but not in men, which was observed in the codominant model (CT vs CC adjusted odds ratio [OR] = 2.46; 95% confidence interval [CI]: 1.37-4.42; p = 0.003; TT vs CC adjusted OR: 2.04; 95% CI: 1.09-3.81; p = 0.03) and the dominant model (CT + TT vs CC adjusted OR: 2.30; 95% CI: 1.31-4.05; p = 0.004). In addition, we found that patients with the MTHFR 677 TT genotype showed a better response to platinum-based chemotherapy in the recessive model (TT vs CT + CC adjusted OR: 0.24; 95% CI: 0.09-0.68; p = 0.007), the generalized OR was 0.44 (0.22-0.88; p = 0.04). There were no significant associations of the polymorphisms of TYMS 3R→2R or MTR 2756 A→G with the risk of NSCLC or response to platinum-based chemotherapy in advanced NSCLC in any genetic model. Our results suggest that genetic polymorphisms of MTHFR 677 C→T may contribute to NSCLC development in Chinese women and could also influence treatment response for advanced NSCLC patients with platinum-based chemotherapy. Further studies with larger sample sizes are required to validate this association.

Non-small cell lung cancer in never smokers as a representative 'non-smoking-associated lung cancer': epidemiology and clinical features

Recent interest in lung cancer without a history of tobacco smoking has led to the classification of a distinct disease entity of 'non-smoking-associated lung cancer'. In this review article, we have made an overview of the recent literature concerning both the epidemiology and clinical features of lung cancer in never smokers, and have brought 'non-smoking-associated lung cancer' into relief. The etiology of lung cancer in never smokers remains indefinite although many putative risk factors have been described including secondhand smoking, occupational exposures, pre-existing lung diseases, diet, estrogen exposure, etc. Non-small cell lung cancer (NSCLC) in never smokers is clinically characterized by an increased incidence in females and a higher occurrence of adenocarcinoma in comparison to NSCLC in ever smokers in both surgical patients and non-resectable advanced-stage patients. Furthermore, the prognosis of never-smoking NSCLC is better than that of smoking-related NSCLC in both surgical patients and non-resectable advanced-stage patients. Recently recognized novel gene mutations such as EGFR (epidermal growth factor receptor) mutations are largely limited to never smokers or light smokers, and the expression of this gene is responsible for the clinical efficacy of gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor. NSCLC with the EML4 (echinoderm microtubule-associated protein-like 4)-ALK (anaplastic lymphoma kinase) fusion gene is also more likely to occur in never smokers and in those with adenocarcinoma histology, and is expected to benefit from ALK inhibitors. In consideration of the future increase in never-smoking NSCLC or 'non-smoking-associated lung cancer', both clinical trials and investigations are needed.

Lung cancer in never smokers

Lung cancer in never smokers (LCINS) has lately been recognized as a unique disease based on rapidly gained knowledge from genomic changes to treatment responses. The focus of this article is on current knowledge and challenges with regard to LCINS expanded from recent reviews highlighting five areas: (1) distribution of LCINS by temporal trends, geographic regions, and populations; (2) three well-recognized environmental risk factors; (3) other plausible environmental risk factors; (4) prior chronic lung diseases and infectious diseases as risk factors; and (5) lifestyles as risk or protective factors. This article will also bring attention to recently published literature in two pioneering areas: (1) histological characteristics, clinical features with emerging new effective therapies, and social and psychological stigma; and (2) searching for susceptibility genes using integrated genomic approaches.

PET/CT imaging in different types of lung cancer: an overview

Lung cancer (LC) still represents one of the most common tumours in both women and men. PET/CT is a whole-body non-invasive imaging procedure that has been increasingly used for the assessment of LC patients. In particular, PET/CT added value to CT is mainly related to a more accurate staging of nodal and metastatic sites and to the evaluation of the response to therapy. Although the most common PET tracer for LC evaluation is 18F-FDG, new tracers have been proposed for the evaluation of lung neuroendocrine tumours (68Ga-DOTA-peptides, 18F-DOPA) and for the assessment of central nervous system metastasis (11C-methionine). This review focuses on the main clinical applications and accuracy of PET/CT for the detection of non-small cells lung cancer (NSCLC), broncho-alveolar carcinoma (BAC), small cells lung cancer (SCLC), lung neuroendocrine tumours (NET) and solitary pulmonary nodules (SPN).

Non-small cell lung cancer in never-smokers: a new disease entity?

Non-small cell lung cancer (NSCLC) in never-smokers is an increasing entity. It seems that it has a different pathogenesis, at least in some cases, making it more sensitive to targeted therapies. Two promising targets have so far been identified. This article gives an overview on the biologic background and latest developments in the treatment of this particular entity.

Epidemiology of lung cancer in women: risk factors, survival, and screening

OBJECTIVE

Lung cancer remains the leading cause of cancer mortality in both men and women. Tobacco use causes the vast majority of lung cancer in women but does not explain all cases, because about one in five women who develop lung cancer have never smoked.

CONCLUSION

Environmental exposures, genetic predisposition, hormonal factors, and viral infection may all play a role in lung cancer in women. A better understanding may provide an avenue to more effective screening, diagnosis, and therapy.

Lung cancer: New biological insights and recent therapeutic advances

Approximately 1.6 million new cases of lung cancer are diagnosed each year throughout the world. In many countries, the mortality related to lung cancer continues to rise. The outcomes for patients with all stages of lung cancer have improved in recent years. The use of systemic therapy in conjunction with local therapy has led to improved cure rates in both resectable and unresectable patient groups. For patients with advanced stage disease, modest but real improvements in overall survival and quality of life have been achieved with systemic chemotherapy. A major focus of research has been the development of molecularly targeted agents and the identification of biomarkers for patient selection. Patients with non-small cell lung cancer with mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain achieve response rates of greater than 70% and superior progression-free survival when treated with an EGFR tyrosine kinase inhibitor compared with standard chemotherapy. This has now emerged as the preferred therapeutic approach for the subset of patients with a mutation in exons 19 or 21 of the EGFR. Another promising targeted approach involves the use of an anaplastic lymphoma kinase (ALK) inhibitor in patients with a translocation involving the echinoderm microtubule-associated protein-like 4 (EML4) and -ALK genes. Finally, a paradigm shift in favor of maintenance therapy for patients with advanced stage disease has gained strength from recent data. All of these advances have been made possible by developing a greater understanding of the biology, the discovery of novel anticancer agents, and improved supportive care measures. This article reviews the major strides made in the treatment of lung cancer in the recent past.

Polymorphisms in inflammatory pathway genes, host factors and lung cancer risk in Chinese female never-smokers

Inflammation appears to be important in lung carcinogenesis among smokers, but its role among never-smokers is not well established. We hypothesized that inflammatory medical conditions and gene polymorphisms interact to increase lung cancer risk in never-smokers. We interviewed 433 Singaporean female never-smoker lung cancer patients and 1375 hospital controls, and evaluated six polymorphisms in the interleukin 1-β, interleukin 6 (IL6), cyclooxygenase-2, peroxisome proliferator-activated receptor-γ and interleukin 1-β receptor antagonist (IL1RN) genes. Tuberculosis was associated with a non-significant elevated risk of lung cancer [odds ratio (OR) 1.58, 95% confidence interval (CI) 0.95-2.62]. There was no effect of asthma, atopy or chronic productive cough individually. However, the presence of one or more of these conditions (asthma, cough or atopy) increased risk (OR 2.24, 95%CI 1.15-4.38) in individuals possessing the T/T genotype at interleukin 1-β -31T/C, but not in those possessing the C/T (OR 0.87, 95%CI 0.51-1.57) or C/C genotypes (OR 0.58, 95%CI 0.27-1.27), and in individuals having the *2 variable number of tandem repeat allele of IL1RN [OR 5.09 (1.39-18.67)], but not in those without (OR 0.93, 95%CI 0.63-1.35). The IL6-634 G allele increased the risk of lung cancer (OR 1.44, 95%CI 1.07-1.94). Lung cancer risk also increased with the number of polymorphism sites where at least 1 'risk' allele was present [interleukin 1-β -31T/C (T allele), IL1RN (*2 allele) and IL6-634C/G (G allele)] among those with asthma, cough or atopy (Ptrend 0.001) but not in those without (Ptrend 0.47). Our results suggest that the effect of inflammatory medical conditions on lung cancer in never-smokers is modulated by host genetic susceptibility and will need to be confirmed in other studies conducted in similar populations.

Survival following non-small cell lung cancer among Asian/Pacific Islander, Latina, and Non-Hispanic white women who have never smoked

BACKGROUND

Lung cancer is the leading cause of cancer death among U.S. Asian/Pacific Islander (API) and Latina women despite low smoking prevalence. This study examined survival patterns following non-small cell lung cancer in a population-based sample of lung cancer cases from the San Francisco Bay Area Lung Cancer Study (SFBALCS).

METHODS

Women diagnosed with lung cancer from 1998 to 2003 and 2005 to 2008 and identified through the Greater Bay Area Cancer Registry were telephone-screened for eligibility for the SFBALCS. The screener data were linked to the cancer registry data to determine follow-up. This analysis included 187 non-Hispanic (NH) white, 23 U.S.-born Latina, 32 foreign-born Latina, 30 U.S.-born API, and 190 foreign-born API never-smokers diagnosed with lung cancer and followed through 2008.

RESULTS

All-cause survival was poorer among APIs [HR=1.7 (95% CI: 1.0-2.8) among U.S.-born APIs and HR=1.2 (95% CI: 0.9-1.5) among foreign-born APIs] and Latinas [HR=2.1 (95% CI: 1.2-3.6) among U.S.-born Latinas; HR=1.4 (95% CI: 0.9-2.3) among foreign-born Latinas] relative to NH whites. These survival differences were not explained by differences in selected sociodemographic or clinical factors.

CONCLUSIONS

Further research should focus on factors such as cultural behaviors, access to or attitudes toward health care, and genetic variations as possible explanations for these striking racial/ethnic differences.

IMPACT

Latina and API female never-smokers diagnosed with lung cancer were up to two times more likely to die than NH whites, highlighting the need for additional research to identify the underlying reasons for the disparities and heightened clinical awareness.

Prognostic impact of local treatment against postoperative oligometastases in non-small cell lung cancer

OBJECTIVES

In this study, we investigated prognostic factors associated with survival after distantly metastatic recurrence in surgically resected non-small cell lung cancer (NSCLC), and clarified the influence of local treatment on the prognosis for oligometastatic recurrence.

METHODS

From 1994 through 2004, 418 consecutive patients with NSCLC underwent complete resection; 138 experienced a postoperative recurrence by December 2005. Of those, we reviewed 93 patients with only distant metastases for clinicopathological information, treatment modality, and survival.

RESULTS

For the 93 patients with distant metastasis alone, the 2- and 5-year survival rates after recurrence were 43.9% and 38.7%, respectively. Of those patients, 44 first received local treatment, including radiotherapy in 31 and a surgical resection in 13. Their recurrent disease (oligometastases) was limited with the potential to be controlled with local treatment. The targeted metastatic organs were brain in 14 patients, bone in 14, lungs in 12, and other organs in 4. Significant prognostic factors for postrecurrence survival included adenocarcinoma histology, long disease-free interval (DFI) (1 year or longer), and the performance of local treatment for oligometastases.

CONCLUSION

Local therapy such as radiotherapy and surgery, might be considered first-line treatment in patients with postoperative oligometastatic recurrence, especially those with a DFI ≥ 1 year.

State of the epidemiological evidence on physical activity and cancer prevention

BACKGROUND

Physical activity is a modifiable lifestyle risk factor that has the potential to reduce the risk of most major cancer sites.

METHODS

We examined the strength, consistency, dose-response and biological plausibility of an association between physical activity and risk of colon, breast, endometrium, lung, prostate, ovarian, gastric, rectal, pancreatic, bladder, testicular, kidney and haematological cancers. We also estimated the population-attributable risk (PAR) for physical inactivity and cancer in 15 European countries.

RESULTS

There is convincing or probable evidence for a beneficial effect of physical activity on the risk of colon, breast and endometrial cancers. The evidence is weaker for ovarian, lung and prostate cancers and generally either null or insufficient for all remaining cancers. Several hypothesised biological mechanisms include a likely effect of physical activity on insulin resistance, body composition, sex steroid hormones and a possible effect on vitamin D, adipokines, inflammation and immune function. Somewhere between 165,000 and 330,000 cases of the six major cancers (breast, colon, lung, prostate, endometrium and ovarian) could have been prevented in 2008 in Europe alone if the population had maintained sufficient levels of physical activity.

CONCLUSION

There is strong and consistent evidence that physical activity reduces the risk of several of the major cancer sites, and that between 9% and 19% of cancer cases could be attributed to lack of sufficient physical activity in Europe. Public health recommendations for physical activity and cancer prevention generally suggest 30-60 min of moderate or vigorous-intensity activity done at least 5d per week.

Non-small cell lung cancer in never smokers: a clinical entity to be identified

OBJECTIVES

It has been recognized that patients with non-small cell lung cancer who are lifelong never-smokers constitute a distinct clinical entity. The aim of this study was to assess clinical risk factors for survival among never-smokers with non-small cell lung cancer.

METHODS

All consecutive non-small cell lung cancer patients diagnosed (n = 285) between May 2005 and May 2009 were included. The clinical characteristics of never-smokers and ever-smokers (former and current) were compared using chi-squared or Student's t tests. Survival curves were calculated using the Kaplan-Meier method, and log-rank tests were used for survival comparisons. A Cox proportional hazards regression analysis was evaluated by adjusting for age (continuous variable), gender (female vs. male), smoking status (never- vs. ever-smoker), the Karnofsky Performance Status Scale (continuous variable), histological type (adenocarcinoma vs. non-adenocarcinoma), AJCC staging (early vs. advanced staging), and treatment (chemotherapy and/or radiotherapy vs. the best treatment support).

RESULTS

Of the 285 non-small cell lung cancer patients, 56 patients were never-smokers. Univariate analyses indicated that the never-smoker patients were more likely to be female (68% vs. 32%) and have adenocarcinoma (70% vs. 51%). Overall median survival was 15.7 months (95% CI: 13.2 to 18.2). The never-smoker patients had a better survival rate than their counterpart, the ever-smokers. Never-smoker status, higher Karnofsky Performance Status, early staging, and treatment were independent and favorable prognostic factors for survival after adjusting for age, gender, and adenocarcinoma in multivariate analysis.

CONCLUSIONS

Epidemiological differences exist between never- and ever-smokers with lung cancer. Overall survival among never-smokers was found to be higher and independent of gender and histological type.

Genomic aberrations in lung adenocarcinoma in never smokers

Background

Lung cancer in never smokers would rank as the seventh most common cause of cancer death worldwide.

Methods and Findings

We performed high-resolution array comparative genomic hybridization analysis of lung adenocarcinoma in sixty never smokers and identified fourteen new minimal common regions (MCR) of gain or loss, of which five contained a single gene (MOCS2, NSUN3, KHDRBS2, SNTG1 and ST18). One larger MCR of gain contained NSD1. One focal amplification and nine gains contained FUS. NSD1 and FUS are oncogenes hitherto not known to be associated with lung cancer. FISH showed that the amplicon containing FUS was joined to the next telomeric amplicon at 16p11.2. FUS was over-expressed in 10 tumors with gain of 16p11.2 compared to 30 tumors without that gain. Other cancer genes present in aberrations included ARNT, BCL9, CDK4, CDKN2B, EGFR, ERBB2, MDM2, MDM4, MET, MYC and KRAS. Unsupervised hierarchical clustering with adjustment for false-discovery rate revealed clusters differing by the level and pattern of aberrations and displaying particular tumor characteristics. One cluster was strongly associated with gain of MYC. Another cluster was characterized by extensive losses containing tumor suppressor genes of which RB1 and WRN. Tumors in that cluster frequently harbored a central scar-like fibrosis. A third cluster was associated with gains on 7p and 7q, containing ETV1 and BRAF, and displayed the highest rate of EGFR mutations. SNP array analysis validated copy-number aberrations and revealed that RB1 and WRN were altered by recurrent copy-neutral loss of heterozygosity.

Conclusions

The present study has uncovered new aberrations containing cancer genes. The oncogene FUS is a candidate gene in the 16p region that is frequently gained in never smokers. Multiple genetic pathways defined by gains of MYC, deletions of RB1 and WRN or gains on 7p and 7q are involved in lung adenocarcinoma in never smokers.