The detection of chromosomal aneusomy by fluorescence in situ hybridization in sputum predicts lung cancer incidence

Liquid Biopsy in Lung Cancer: Biomarkers for the Management of Recurrence and Metastasis

Liquid biopsies have emerged as a promising tool for the detection of metastases as well as local and regional recurrence in lung cancer. Liquid biopsy tests involve analyzing a patient's blood, urine, or other body fluids for the detection of biomarkers, including circulating tumor cells or tumor-derived DNA/RNA that have been shed into the bloodstream. Studies have shown that liquid biopsies can detect lung cancer metastases with high accuracy and sensitivity, even before they are visible on imaging scans. Such tests are valuable for early intervention and personalized treatment, aiming to improve patient outcomes. Liquid biopsies are also minimally invasive compared to traditional tissue biopsies, which require the removal of a sample of the tumor for further analysis. This makes liquid biopsies a more convenient and less risky option for patients, particularly those who are not good candidates for invasive procedures due to other medical conditions. While liquid biopsies for lung cancer metastases and relapse are still being developed and validated, they hold great promise for improving the detection and treatment of this deadly disease. Herein, we summarize available and novel approaches to liquid biopsy tests for lung cancer metastases and recurrence detection and describe their applications in clinical practice.

Autoantibodies against tumor-associated antigens in sputum as biomarkers for lung cancer

Tumor antigens (TAs) can initiate host immune responses and produce TA-associated autoantibody (TAAbs), potential cancer biomarkers. Sputum is directly generated from the upper and lower airways, and thus can be used as a surrogate sample for the diagnosis of lung cancer based on molecular analysis. To develop sputum TAAb biomarkers for the early detection of lung cancer, the leading cause of cancer death, we probed a protein microarray containing more than 9,000 antigens with sputum supernatants of a discovery set of 30 lung cancer patients and 30 cancer-free smokers. Twenty-eight TAs with higher reactivity in sputum of lung cancer cases vs. controls were identified. The diagnostic significance of TAAbs against the TAs was determined by enzyme-linked immunosorbent assays (ELISAs) in sputum of the discovery set and additional 166 lung cancer patients and 213 cancer-free smokers (validation set). Three sputum TAAbs against DDX6, ENO1, and 14-3-3ζ were developed as a biomarker panel with 81% sensitivity and 83% specificity for diagnosis of lung cancer, regardless of stages, locations, and histological types of lung tumors. This study provides the first evidence that sputum TAAbs could be used as biomarkers for the early detection of lung cancer.

MicroRNAs in sputum specimen as noninvasive biomarkers for the diagnosis of nonsmall cell lung cancer: An updated meta-analysis

BACKGROUND

Nonsmall cell lung cancer (NSCLC) is a serious leading cause of death worldwide. Recently, multiple researches have identified that microRNA (miRNA) in sputum could be a useful tool for NSCLC diagnosis. The objective of this study was to assess whether aberrant miRNA expression could be regarded as a useful biomarker in sputum specimen for the diagnosis of NSCLC.

METHODS

Eligible studies were searched in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, and VIP databases up to June 2018. We calculated the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) to investigate the diagnostic value of miRNA in sputum for NSCLC. MetaDisc1.4 and STATA12.0 were used to analyze the retrieved data.

RESULTS

Finally, a total of 14 articles were included in this meta-analysis involving 1009 NSCLC patients and 1006 controls. The results were as followed: the pooled sensitivity, specificity, PLR, NLR, DOR, were 0.75 (95%CI:0.72-0.78), 0.88 (95%CI:0.86-0.90), 5.70 (95%CI:4.82-6.75), 0.30 (95%CI:0.26-0.34), 22.43 (95%CI:17.48-28.79), respectively. The AUC of overall summary receiver operator characteristic curve (SROC) was 0.8917.

CONCLUSION

Our comprehensive analysis indicated that miRNAs in sputum specimen may be noninvasive diagnostic biomarkers for NSCLC. However, much more studies should be conducted before clinical application.

Clinical Utility of Chromosomal Aneusomy in Individuals at High Risk of Lung Cancer

INTRODUCTION

Low-dose computed tomography screening for lung cancer has a high false-positive rate with frequent discovery of indeterminate pulmonary nodules. Noninvasive biomarkers are needed to reduce false positives and improve risk stratification. A retrospective longitudinal evaluation was performed to assess chromosomal aneusomy in sputum by fluorescence in situ hybridization (CA-FISH) in four nested case-control studies.

METHODS

Receiver operating characteristic analysis resulted in two grouped cohorts: a high-risk cohort (Colorado High-Risk Cohort and Colorado Nodule Cohort [68 case patients and 69 controls]) and a screening cohort (American College of Radiology Imaging Network/National Lung Screening Trial and Pittsburgh Lung Screening Study [97 case patients and 185 controls]). The CA-FISH assay was a four-target DNA panel encompassing the EGFR and v-myc avian myelocytomatosis viral oncogene homolog (MYC) genes, and the 5p15 and centromere 6 regions or the fibroblast growth factor 1 gene (FGFR1) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha gene (PIK3CA). A four-category scale (normal, probably normal, probably abnormal, and abnormal) was applied. Sensitivity, specificity, and positive and negative likelihood ratios (LRs) (with 95% confidence intervals [CIs]) were estimated for each cohort.

RESULTS

Sensitivity and specificity were, respectively, 0.67 (95% CI: 0.55-0.78) and 0.94 (95% CI: 0.85-0.98) for high-risk participants and 0.20 (95% CI: 0.13-0.30) and 0.84 (95% CI: 0.78-0.89) for screening participants. The positive and negative LRs were, respectively, 11.66 (95% CI: 4.44-30.63) and 0.34 (95% CI: 0.24-0.48) for high-risk participants and 1.36 (95% CI: 0.81-2.28) and 0.93 (95% CI: 0.83-1.05) for screening participants.

CONCLUSION

The high positive LR of sputum CA-FISH indicates that it could be a useful adjunct to low-dose computed tomography for lung cancer in high-risk settings. For screening, however, its low positive LR limits clinical utility. Prospective assessment of CA-FISH in the incidentally identified indeterminate nodule setting is ongoing in the Colorado Pulmonary Nodule Biomarker Trial.

Biomarkers of risk to develop lung cancer in the new screening era

Low-dose computed tomography for high-risk individuals has for the first time demonstrated unequivocally that early detection save lives. The currently accepted screening strategy comes at the cost of a high rate of false positive findings while still missing a large percentage of the cases. Therefore, there is increasing interest in developing strategies to better estimate the risk of an individual to develop lung cancer, to increase the sensitivity of the screening process, to reduce screening costs and to reduce the numbers of individuals harmed by screening and follow-up interventions. New molecular biomarkers candidates show promise to improve lung cancer outcomes. This review discusses the current state of biomarker research in lung cancer screening with the primary focus on risk assessment.

Analysis of MicroRNAs in sputum to improve computed tomography for lung cancer diagnosis

INTRODUCTION

Computed tomography (CT) plays a central role in lung cancer diagnosis. However, CT has relatively low specificity, presenting a challenge in clinical settings. We previously identified 12 microRNAs (miRNAs) whose expressions in tumor tissues were associated with lung cancer.

METHODS

Using quantitative reverse transcriptase polymerase chain reaction, we aimed to identify miRNA biomarkers in sputum that could complement CT for diagnosis of lung cancer.

RESULTS

In a training set consisting of 66 lung cancer patients and 68 cancer-free smokers, 10 of the 12 miRNAs were differentially expressed between the cases and controls (p ≤ 0.01). From the miRNAs, a logistic regression model was built on the basis of miR-31 and miR-210, both of which had the best prediction for lung cancer, producing an area under receiver operating characteristic curve of 0.83. Combined use of the two miRNAs yielded 65.2% sensitivity and 89.7% specificity, CT had 93.9% sensitivity and 83.8% specificity for lung cancer diagnosis. Notably, combined analysis of the miRNA biomarkers and CT produced a higher specificity than does CT used alone (91.2% versus 83.8%; p < 0.05). The diagnostic performance of the biomarkers was confirmed in a testing set comprising 64 lung cancer patients and 73 cancer-free smokers.

CONCLUSION

The sputum miRNA biomarkers might be useful in improving CT for diagnosis of lung cancer, but further independent validation on an external and prospective cohort of patients is required.

Convergence of nanotechnology and cancer prevention: are we there yet?

Nanotechnology is emerging as a promising modality for cancer treatment; however, in the realm of cancer prevention, its full utility has yet to be determined. Here, we discuss the potential of integrating nanotechnology in cancer prevention to augment early diagnosis, precision targeting, and controlled release of chemopreventive agents, reduced toxicity, risk/response assessment, and personalized point-of-care monitoring. Cancer is a multistep, progressive disease; the functional and acquired characteristics of the early precancer phenotype are intrinsically different from those of a more advanced anaplastic or invasive malignancy. Therefore, applying nanotechnology to precancers is likely to be far more challenging than applying it to established disease. Frank cancers are more readily identifiable through imaging and biomarker and histopathologic assessment than their precancerous precursors. In addition, prevention subjects routinely have more rigorous intervention criteria than therapy subjects. Any nanopreventive agent developed to prevent sporadic cancers found in the general population must exhibit a very low risk of serious side effects. In contrast, a greater risk of side effects might be more acceptable in subjects at high risk for cancer. Using nanotechnology to prevent cancer is an aspirational goal, but clearly identifying the intermediate objectives and potential barriers is an essential first step in this exciting journey.

Identification of ENO1 as a potential sputum biomarker for early-stage lung cancer by shotgun proteomics

BACKGROUND

Lung cancer is the leading cancer killer. Early detection will reduce the related deaths. The objective of this study was to identify potential biomarkers for early-stage lung cancer in sputum supernatant.

MATERIALS AND METHODS

Using shotgun proteomics, we detected changes in protein profiles that were associated with lung cancer by analyzing sputum supernatants from 6 patients with early-stage lung cancer and 5 cancer-free controls. Using western blotting, we validated the proteomic results in 22 lung cancer cases and 22 controls. Using enzyme-linked immunosorbent assay (ELISA), we evaluated the diagnostic performance of the biomarker candidates in an independent set of 35 cases and 36 controls.

RESULTS

Proteomics identified 8 biomarker candidates for lung cancer. Western blotting validation of the candidates showed that enolase 1 (ENO1) displayed a higher expression level in patients with cancer than in cancer-free individuals (P = .015). ELISA revealed that the assessment of ENO1 expression in sputum supernatant had 58.33% sensitivity and 80.00% specificity in distinguishing patients with stage I lung cancer from cancer-free individuals.

CONCLUSION

The analysis of protein biomarkers in sputum may provide a potential approach for the early detection of lung cancer. Future validation of all the candidates defined by shotgun proteomics in a large cohort study may help develop additional biomarkers that can be added to ENO1 to provide more diagnostic efficacy for lung cancer.

Evaluation of lung flute in sputum samples for molecular analysis of lung cancer

Background

Molecular analysis of sputum provides a promising approach for lung cancer diagnosis, yet is limited by the difficulty in collecting the specimens from individuals who can’t spontaneously expectorate sputum. Lung Flute is a small self-powered audio device that can induce sputum by generating sound waves and vibrating in the airways of the lungs. Here we propose to evaluate the usefulness of Lung Flute for sputum sampling to assist diagnosis of lung cancer.

Methods

Forty-three stage I lung cancer patients and 47 cancer-free individuals who couldn’t spontaneously cough sputum were instructed to use Lung Flute for sputum sampling. Expressions of two microRNAs, miRs-31 and 210, were determined in the specimens by qRT-PCR. The results were compared with sputum cytology.

Results

Sputum was easily collected from 39 of 43 (90.7%) lung cancer patients and 42 of 47 (89.4%) controls with volume ranges from 1 to 5 ml (median, 2.6 ml). The specimens had less than 4% oral squamous cells, indicating that sputum was obtained from low respiratory tract. Expressions of miRs-31 and 210 in sputum were considerably higher in cancer patients than cancer-free individuals (8.990 vs. 4.514; 0.6847 vs. 0.3317; all P <0.001). Combined use of the two miRNAs produced a significantly higher sensitivity (61.5% vs. 35.9%, P = 0.002) and a slightly lower specificity (90.5% vs. 95.2%, p = 0.03) compared with cytology for lung cancer diagnosis.

Conclusion

Lung Flute could potentially be useful in convenient and efficient collection of sputum for molecular diagnosis of lung cancer.

Epidemiology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Ever since a lung cancer epidemic emerged in the mid-1900 s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research.

METHODS

A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk.

RESULTS

Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application.

CONCLUSIONS

Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers.

Diagnosis and treatment of bronchial intraepithelial neoplasia and early lung cancer of the central airways: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Bronchial intraepithelial lesions may be precursors of central airway lung carcinomas. Identification and early treatment of these preinvasive lesions might prevent progression to invasive carcinoma.

METHODS

We systematically reviewed the literature to develop evidence-based recommendations regarding the diagnosis and treatment of intraepithelial lesions.

RESULTS

The risk and timeline for progression of bronchial intraepithelial lesions to carcinoma in situ (CIS) or invasive carcinoma are not well understood. Multiple studies show that autofluorescence bronchoscopy (AFB) is more sensitive that white light bronchoscopy (WLB) to identify these lesions. In patients with severe dysplasia or CIS in sputum cytology who have chest imaging studies showing no localizing abnormality, we suggest use of WLB; AFB may be used as an adjunct when available. Patients with known severe dysplasia or CIS of central airways should be followed with WLB or AFB, when available. WLB or AFB is also suggested for patients with early lung cancer who will undergo resection for delineation of tumor margins and assessment of synchronous lesions. However, AFB is not recommended prior to endobronchial therapy for CIS or early central lung cancer. Several endobronchial techniques are recommended for the treatment of patients with superficial limited mucosal lung cancer who are not candidates for resection.

CONCLUSION

Additional information is needed about the natural history and rate of progression of preinvasive central airway lesions. Patients with severe dysplasia or CIS may be treated endobronchially; however, it remains unclear if these therapies are associated with improved patient outcomes.

What is the most practical, optimal, and cost effective method for performing follow-up after lung cancer surgery, and by whom should it be done?

Surgery is the treatment of choice for early stage non-small cell lung cancer. In this context, postoperative follow-up is important to diagnose late postoperative complications, as well as to detect recurring cancer or new primaries as early as possible. There is, however, no high-quality evidence regarding the benefits of monitoring programs on survival and quality of life. Most studies recommend clinical and radiological follow-up (radiograph or chest computed tomography) performed more intensively during the first two years and annually thereafter. The physician doing the follow-up can be the thoracic surgeon, the diagnosing physician, or the family physician.

Chemoprevention of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Lung cancer is the most common cause of cancer death in men and women in the United States. Cigarette smoking is the main risk factor. Former smokers are at a substantially increased risk of developing lung cancer compared with lifetime never smokers. Chemoprevention refers to the use of specific agents to reverse, suppress, or prevent the process of carcinogenesis. This article reviews the major agents that have been studied for chemoprevention.

METHODS

Articles of primary, secondary, and tertiary prevention trials were reviewed and summarized to obtain recommendations.

RESULTS

None of the phase 3 trials with the agents β-carotene, retinol, 13-cis-retinoic acid, α-tocopherol, N-acetylcysteine, acetylsalicylic acid, or selenium has demonstrated beneficial and reproducible results. To facilitate the evaluation of promising agents and to lessen the need for a large sample size, extensive time commitment, and expense, surrogate end point biomarker trials are being conducted to assist in identifying the most promising agents for later-stage chemoprevention trials. With the understanding of important cellular signaling pathways and the expansion of potentially important targets, agents (many of which target inflammation and the arachidonic acid pathway) are being developed and tested which may prevent or reverse lung carcinogenesis.

CONCLUSIONS

By integrating biologic knowledge, additional early-phase trials can be performed in a reasonable time frame. The future of lung cancer chemoprevention should entail the evaluation of single agents or combinations that target various pathways while working toward identification and validation of intermediate end points.

Molecular biology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

Based on recent bench and clinical research, the treatment of lung cancer has been refined, with treatments allocated according to histology and specific molecular features. For example, targeting mutations such as epidermal growth factor receptor (EGFR) with tyrosine kinase inhibitors has been particularly successful as a treatment modality, demonstrating response rates in selected patients with adenocarcinoma tumors harboring EGFR mutations that are significantly higher than those for conventional chemotherapy. However, the development of new targeted therapies is, in part, highly dependent on an improved understanding of the molecular underpinnings of tumor initiation and progression, knowledge of the role of molecular aberrations in disease progression, and the development of highly reproducible platforms for high-throughput biomarker discovery and testing. In this article, we review clinically relevant research directed toward understanding the biology of lung cancer. The clinical purposes of this research are (1) to identify susceptibility variants and field molecular alterations that will promote the early detection of tumors and (2) to identify tumor molecular alterations that serve as therapeutic targets, prognostic biomarkers, or predictors of tumor response. We focus on research developments in the understanding of lung cancer somatic DNA mutations, chromosomal aberrations, epigenetics, and the tumor microenvironment, and how they can advance diagnostics and therapeutics.

Detection of lung cancer using multiple genetic markers--a systematic review

Lung cancer is the leading cause of cancer deaths worldwide, and has one of the lowest survival rates of any solid tumor. In recent years, several attempts have been conducted to improve an early or accelerated diagnosis due to better overall prognosis after therapy. The aim of this study was evaluating the use of genetic markers for diagnosis of lung cancer. This study was conducted in accordance to Transparent Reporting of Systematic Reviews and Meta-Analyses. Three Internet sources were used to search: MEDLINE-PubMed, EMBASE, and LILACS. The databases were searched for studies conducted in the period up to and including May 10, 2011. The following inclusion criteria were applied: lung cancer studies, and the use of genetic markers for diagnosis. Studies using animal models, review articles, meta-analyses, abstracts, conference proceedings, editorials/letters, case reports, incorrect study population, inadequate data, and cytology was not obtained, were excluded. A total of 1,901 abstracts/citations were identified for preliminary review. From 24 final selected studies, 17 referred to chromosomal markers diagnosis, eight to genes as marker, and one to both subjects. Fluorescence in situ hybridization (FISH) was applied in all studies. Despite the limitations of this study, application of genetic markers to lung cancer diagnosis seems to have prognosis value irrespective of detection methodology used. FISH was the main technique applied to diagnose genetics alterations and revealed a high specificity, although some authors reported low sensitivity.

Screening for Lung Cancer: Who Should Be Screened?

Lung cancer is the most common cause of death from cancer in the United States. Previous studies of screening with chest radiographs and sputum cytology have not been shown to decrease lung cancer mortality. For the first time, a randomized screening trial with low-dose computed tomography scans has demonstrated a 20% lung cancer mortality reduction compared with screenings with a chest x-ray. Investigation is underway on many breath, sputum, and blood biomarkers to determine markers of high risk. The hope is that some (or one) of them will add to the early detection of lung cancer observed with low-dose computed tomography.

Surveillance of resected non-small cell lung cancer

Lung cancer is the most common cancer in the world. 15 % of all patients with lung cancer are diagnosed at an early stage, and surgery is the treatment of choice for them. 40 % of all patients survive more than 5 years after surgery, and most of them die as a result of systemic disease. Half of all recurrences are diagnosed within the first 24 months after curative treatment, and 90 % in the first 5 years. Despite this, it is not standardized who should do the monitoring, what additional tests are needed and how often should they be performed. We present here a review on the various recommendations in clinical guidelines.

Defining a gene promoter methylation signature in sputum for lung cancer risk assessment

PURPOSE

To evaluate the methylation state of 31 genes in sputum as biomarkers in an expanded nested, case-control study from the Colorado cohort, and to assess the replication of results from the most promising genes in an independent case-control study of asymptomatic patients with stage I lung cancer from New Mexico.

EXPERIMENTAL DESIGN

Cases and controls from Colorado and New Mexico were interrogated for methylation of up to 31 genes using nested, methylation-specific PCR. Individual genes and methylation indices were used to assess the association between methylation and lung cancer with logistic regression modeling.

RESULTS

Seventeen genes with ORs of 1.4 to 3.6 were identified and selected for replication in the New Mexico study. Overall, the direction of effects seen in New Mexico was similar to Colorado with the largest increase in case discrimination (ORs, 3.2-4.2) seen for the PAX5α, GATA5, and SULF2 genes. Receiver operating characteristic (ROC) curves generated from seven-gene panels from Colorado and New Mexico studies showed prediction accuracy of 71% and 77%, respectively. A 22-fold increase in lung cancer risk was seen for a subset of New Mexico cases with five or more genes methylated. Sequence variants associated with lung cancer did not improve the accuracy of this gene methylation panel.

CONCLUSIONS

These studies have identified and replicated a panel of methylated genes whose integration with other promising biomarkers could initially identify the highest risk smokers for computed tomographic screening for early detection of lung cancer.

Update on biomarkers for the detection of lung cancer

Patients at risk for lung cancer may have subclinical disease for years before presentation. The diagnosis of this disease is primarily based on symptoms, and detection often occurs after curative intervention is no longer possible. At present, no lung cancer early-detection biomarker is clinically available. This study reviews the most recent advances in early detection and molecular diagnostic biomarkers for the detection of lung cancer. This review includes an overview of the various biological specimens and matrices in which these biomarkers could be analyzed, as well as the diverse strategies and approaches for identifying new biomarkers that are currently being explored. Several novel and attractive biomarker candidates for the early detection of lung cancer exist. A remarkable shift is taking place from research based on single markers to analyzing signatures that are more complex in order to take advantage of new high-throughput technologies. However, it is still necessary to validate the most promising markers and the standardization of procedures that will lead to specific clinical applications.

Non-small-cell lung cancer

In the decade since the last Lancet Seminar on lung cancer there have been advances in many aspects of the classification, diagnosis, and treatment of non-small-cell lung cancer (NSCLC). An international panel of experts has been brought together to focus on changes in the epidemiology and pathological classification of NSCLC, the role of CT screening and other techniques that could allow earlier diagnosis and more effective treatment of the disease, and the recently introduced seventh edition of the TNM classification and its relation to other prognostic factors such as biological markers. We also describe advances in treatment that have seen the introduction of a new generation of chemotherapy agents, a proven advantage to adjuvant chemotherapy after complete resection for specific stage groups, new techniques for the planning and administration of radiotherapy, and new surgical approaches to assess and reduce the risks of surgical treatment.

Solid tumor cytogenetics: current perspectives

Conventional cytogenetics in conjunction with Fluorescence in Situ Hybridization (FISH) continues to remain an important and integral component in the diagnosis and management of solid tumors. The ability to effectively detect the vast majority of clinically relevant chromosomal aberrations with a rapid-to-acceptable turnaround time makes them the most cost-effective screening/detection tool currently available in modern pathology. In this review, we describe a representative set of solid tumors in which chromosomal analysis and/or FISH plays a significant role in the routine clinical management of solid tumors.

Sputum-based molecular biomarkers for the early detection of lung cancer: limitations and promise

Lung cancer is the leading cause of cancer deaths, with an overall survival of 15% at five years. Biomarkers that can sensitively and specifically detect lung cancer at early stage are crucial for improving this poor survival rate. Sputum has been the target for the discovery of non-invasive biomarkers for lung cancer because it contains airway epithelial cells, and molecular alterations identified in sputum are most likely to reflect tumor-associated changes or field cancerization caused by smoking in the lung. Sputum-based molecular biomarkers include morphology, allelic imbalance, promoter hypermethylation, gene mutations and, recently, differential miRNA expression. To improve the sensitivity and reproducibility of sputum-based biomarkers, we recommend standardization of processing protocols, bronchial epithelial cell enrichment, and identification of field cancerization biomarkers.

[Advances in early diagnosis of lung cancer]

Lung cancer is the most common cause of cancer death worldwide. Early diagnosis and early treatment are of great importance. Chest X-ray, spinal CT, bronchoscopy and sputum cytology have long been used as screening or diagnostic modalities for early detection of lung cancer. However, these methods have limitations in sensitivity, specificity or utility in some degree. In recent years, researchers all over the world have done lots of work on finding and identifying biomarkers for the early diagnosis of lung cancer. In this paper, recent developments in this field are reviewed.

Lung cancer after heart transplantation: results from a large multicenter registry

In this study we analyzed Spanish Post-Heart-Transplant Tumour Registry data for adult heart transplantation (HT) patients since 1984. Median post-HT follow-up of 4357 patients was 6.7 years. Lung cancer (mainly squamous cell or adenocarcinoma) was diagnosed in 102 (14.0% of patients developing cancers) a mean 6.4 years post-HT. Incidence increased with age at HT from 149 per 100 000 person-years among under-45s to 542 among over-64s; was 4.6 times greater among men than women; and was four times greater among pre-HT smokers (2169 patients) than nonsmokers (2188). The incidence rates in age-at-diagnosis groups with more than one case were significantly greater than GLOBOCAN 2002 estimates for the general Spanish population, and comparison with published data on smoking and lung cancer in the general population suggests that this increase was not due to a greater prevalence of smokers or former smokers among HT patients. Curative surgery, performed in 21 of the 28 operable cases, increased Kaplan-Meier 2-year survival to 70% versus 16% among inoperable patients.

Screening and early detection of lung cancer

Lung cancer with an estimated 342,000 deaths in 2008 (20% of total) is the most common cause of death from cancer, followed by colorectal cancer (12%), breast cancer (8%), and stomach cancer (7%) in Europe. In former smokers, the absolute lung cancer risk remains higher than in never-smokers; these data therefore call for effective secondary preventive measures for lung cancer in addition to smoking cessation programs. This review presents and discusses the most recent advances in the early detection and screening of lung cancer.An overview of randomized controlled computerized tomography-screening trials is given, and the role of bronchoscopy and new techniques is discussed. Finally, the approach of (noninvasive) biomarker testing in the blood, exhaled breath, sputum, and bronchoscopic specimen is reviewed.

Equivocal cytology in lung cancer diagnosis: improvement of diagnostic accuracy using adjuvant multicolor FISH, DNA-image cytometry, and quantitative promoter hypermethylation analysis

BACKGROUND

Sometimes, cytological lung cancer diagnosis is challenging because equivocal diagnoses are common. To enhance diagnostic accuracy, fluorescent in situ hybridization (FISH), DNA-image cytometry, and quantitative promoter hypermethylation analysis have been proposed as adjuncts.

METHODS

Bronchial washings and/or brushings or transbronchial fine-needle aspiration biopsies were prospectively collected from patients who were clinically suspected of having lung carcinoma. After routine cytological diagnosis, 70 consecutive specimens, each cytologically diagnosed as negative, equivocal, or positive for cancer cells, were investigated with adjuvant methods. Suspicious areas on the smears were restained with the LAVysion multicolor FISH probe set (Abbott Molecular, Des Plaines, Illinois) or according to the Feulgen Staining Method for DNA-image cytometry analysis. DNA was extracted from residual liquid material, and frequencies of aberrant methylation of APC, p16(INK4A) , and RASSF1A gene promoters were determined with quantitative methylation-specific polymerase chain reaction (QMSP) after bisulfite conversion. Clinical and histological follow-up according to a reference standard, defined in advance, were available for 198 of 210 patients.

RESULTS

In the whole cohort, cytology, FISH, DNA-image cytometry, and QMSP achieved sensitivities of 83.7%, 78%, 79%, and 49.6%, respectively (specificities of 69.8%, 98.2%, 98.2%, and 98.4%, respectively). Subsequent to cytologically equivocal diagnoses, FISH, DNA-image cytometry, and QMSP definitely identified malignancy in 79%, 83%, and 49%, respectively. With QMSP, 4 of 22 cancer patients with cytologically negative diagnoses were correctly identified.

CONCLUSIONS

Thus, adjuvant FISH or DNA-image cytometry in cytologically equivocal diagnoses improves diagnostic accuracy at comparable rates. Adjuvant QMSP in cytologically negative cases with persistent suspicion of lung cancer would enhance sensitivity.

Incremental value of pulmonary function and sputum DNA image cytometry in lung cancer risk prediction

Lung cancer is the leading cause of cancer death worldwide. Accurate prediction of lung cancer risk is of value for individuals, clinicians, and researchers. The aims of this study were to characterize the associations between pulmonary function and sputum DNA image cytometry (SDIC) and lung cancer, and their contributions to risk prediction. During 1990 to 2007, 2,596 high-risk individuals were enrolled and followed prospectively for development of lung cancer (n = 139; median follow-up 7.7 years) in trials at the British Columbia Cancer Agency. At baseline, an epidemiologic questionnaire was administered, sputum was collected for aneuploidy measurement and spirometry was obtained. Multivariable logistic models were prepared including known lung cancer predictors (model 1), that additionally included percent-expected-forced expiratory volume in 1 second [forced expiratory volume in 1 second (FEV(1)%), model 2], and that additionally included SDIC (model 3). Prediction was assessed by evaluating discrimination (receiver operator characteristic area under the curve (ROC AUC)) and calibration. Net reclassification indices (NRI) were calculated with cutoff points for 8-year risks identifying low, intermediate, and high risk at 1.5% and 3%. Lung cancer risk increased with decline in FEV(1)%, but did so more for men than for women (interaction P < 0.001). SDIC demonstrated a dose-response with lung cancer (P = 0.022). The ROC AUCs for models 1, 2, and 3 were 0.718 (95% CI: 0.671-0.765), 0.767 (95% CI: 0.725-0.809), and 0.773 (95% CI: 0.732-0.815), respectively. Model 2 versus 1 had a NRI of 12.6% (P < 0.0001) and model 3 versus 2 had a NRI of 3.1% (P = 0.059). Spirometry and SDIC data substantially and minimally improved lung cancer prediction, respectively.

De novo generation of white adipocytes from the myeloid lineage via mesenchymal intermediates is age, adipose depot, and gender specific

It is generally assumed that white adipocytes arise from resident adipose tissue mesenchymal progenitor cells. We challenge this paradigm by defining a hematopoietic origin for both the de novo development of a subset of white adipocytes in adults and a previously uncharacterized adipose tissue resident mesenchymal progenitor population. Lineage and cytogenetic analysis revealed that bone marrow progenitor (BMP)-derived adipocytes and adipocyte progenitors arise from hematopoietic cells via the myeloid lineage in the absence of cell fusion. Global gene expression analysis indicated that the BMP-derived fat cells are bona fide adipocytes but differ from conventional white or brown adipocytes in decreased expression of genes involved in mitochondrial biogenesis and lipid oxidation, and increased inflammatory gene expression. The BMP-derived adipocytes accumulate with age, occur in higher numbers in visceral than in subcutaneous fat, and in female versus male mice. BMP-derived adipocytes may, therefore, account in part for adipose depot heterogeneity and detrimental changes in adipose metabolism and inflammation with aging and adiposity.

Unprecedented opportunities and promise for cancer prevention research

Cancer prevention encompasses a wide range of highly developed science and clinical impact. Enunciating these two aspects in the same breath highlights the crucial link between them. The breadth and excitement of current opportunities in the science of cancer prevention have never been greater. Major avenues of such research include the extent and effect of premalignancy, the molecular underpinnings of carcinogenesis and related prevention targets, in vitro model systems of the progression of normal human epithelial cells to tumorigenesis, molecular risk stratification and pharmacogenomic approaches, and many more. We describe the clinical impacts of cancer prevention (with examples in the areas of molecular targeting, vaccines, epidemiology, and behavioral science) and the stage-setting science that facilitated them. In addition, discussed are new prevention opportunities such as interactions between stromal and microenvironmental factors, the control of premalignant stem cell phenotypes through epigenetic reprogramming, and neoplastic cells and various stress responses including those involving telomere biology. The promise of this science, particularly integrative, interdisciplinary research, is to hasten the ability of clinical prevention to reduce the burden of cancer.

Interphase cytogenetics of sputum cells for the early detection of lung carcinogenesis

This perspective on Varella-Garcia et al. (beginning on p. 447 in this issue of the journal) examines the role of interphase fluorescence in situ hybridization for the early detection of lung cancer. This work is an important step toward identifying and validating a molecular marker in sputum samples for lung cancer early detection and highlights the value of establishing cohort studies with biorepositories of samples collected from participants followed over time for disease development.

Lung cancer biomarkers: FISHing in the sputum for risk assessment and early detection

This perspective on Varella-Garcia et al. (beginning on p. 447 in this issue of the journal) discusses the role of sputum-based biomarkers in the risk assessment and early detection of lung cancer. The importance of the detection of sputum epithelial chromosomal aneusomy by fluorescence in situ hybridization (FISH) as a potential risk or early-detection biomarker is discussed in the context of other biomarkers and models in lung carcinogenesis. The presently reported findings on FISH in sputum cells are an important contribution worthy of further investigation in defined clinical settings.