Lung cancer mortality in the Mayo Lung Project: impact of extended follow-up

Application of cancer genomics to solve unmet clinical needs

The large amount of data on cancer genome research has contributed to our understanding of cancer biology. Indeed, the genomics approach has a strong advantage for analyzing multi-factorial and complicated problems, such as cancer. It is time to think about the actual usage of cancer genomics in the clinical field. The clinical cancer field has lots of unmet needs in the management of cancer patients, which has been defined in the pre-genomic era. Unmet clinical needs are not well known to bioinformaticians and even non-clinician cancer scientists. A personalized approach in the clinical field will bring potential additional challenges to cancer genomics, because most data to now have been population-based rather than individual-based. We can maximize the use of cancer genomics in the clinical field if cancer scientists, bioinformaticians, and clinicians think and work together in solving unmet clinical needs. In this review, we present one imaginary case of a cancer patient, with which we can think about unmet clinical needs to solve with cancer genomics in the diagnosis, prediction of prognosis, monitoring the status of cancer, and personalized treatment decision.

[Advance of lung cancer screening with low-dose spiral CT]

Lung cancer has become the leading cause of cancer mortality globally, and 5-year survival rate is very poor. Screening and early detection are vital to improve survival and decrease mortality of lung cancer. In recent 20 years, low-dose spiral CT (LDCT) screening has become a research focus in this area. Randomized controlled trials have confirmed that LDCT can decrease lung cancer mortality. However, there are still some problems of LDCT. In this paper, we summarized the controversy that whether low-dose helical CT screening can reduce lung cancer mortality or not before its effectiveness was been confirmed, the results and problems in the randomized controlled trials and gave a prospect of low-dose helical CT screening's future application.

Bone suppressed images improve radiologists' detection performance for pulmonary nodules in chest radiographs

OBJECTIVES

To assess the effect of bone suppression imaging on observer performance in detecting lung nodules in chest radiographs.

MATERIALS AND METHODS

Posteroanterior (PA) and lateral digital chest radiographs of 111 (average age 65) patients with a CT proven solitary nodule (median diameter 15 mm), and 189 (average age 63) controls were read by 5 radiologists and 3 residents. Conspicuity of nodules on the radiographs was classified in obvious (n = 32), moderate (n = 32), subtle (n = 29) and very subtle (n = 18). Observers read the PA and lateral chest radiographs without and with an additional PA bone suppressed image (BSI) (ClearRead Bone Suppression 2.4, Riverain Technologies, Ohio) within one reading session. Multi reader multi case (MRMC) receiver operating characteristics (ROC) were used for statistical analysis.

RESULTS

ROC analysis showed improved detection with use of BSI compared to chest radiographs alone (AUC = 0.883 versus 0.855; p = 0.004). Performance also increased at high specificities exceeding 80% (pAUC = 0.136 versus 0.124; p = 0.0007). Operating at a specificity of 90%, sensitivity increased with BSI from 66% to 71% (p = 0.0004). Increase of detection performance was highest for nodules with moderate and subtle conspicuity (p = 0.02; p = 0.03).

CONCLUSION

Bone suppressed images improve radiologists' detection performance for pulmonary nodules, especially for those of moderate and subtle conspicuity.

Measuring the mortality impact of breast cancer screening

OBJECTIVE

To i) estimate how large the mortality reductions would be if women were offered screening from age 50 until age 69; ii) to do so using the same trials and participation rates considered by the Canadian Task Force; iii) but to be guided in our analyses by the critical differences between cancer screening and therapeutics, by the time-pattern that characterizes the mortality reductions produced by a limited number of screens, and by the year-by-year mortality data in the appropriate segment of follow-up within each trial; and thereby iv) to avoid the serious underestimates that stem from including inappropriate segments of follow-up, i.e., too soon after study entry and too late after discontinuation of screening.

METHODS

We focused on yearly mortality rate ratios in the follow-up years where, based on the screening regimen employed, mortality deficits would be expected. Because the regimens differed from trial to trial, we did not aggregate the yearly data across trials. To avoid statistical extremes arising from the small numbers of yearly deaths in each trial, we calculated rate ratios for 3-year moving windows.

RESULTS

We were able to extract year-specific data from the reports of five of the trials. The data are limited for the most part by the few rounds of screening. Nevertheless, they suggest that screening from age 50 until age 69 would, at each age from 55 to 74, result in breast cancer mortality reductions much larger than the estimate of 21% that the Canadian Task Force report is based on.

DISCUSSION

By ignoring key features of cancer screening, several of the contemporary analyses have seriously underestimated the impact to be expected from such a program of breast cancer screening.

Levels of circulating microparticles in lung cancer patients and possible prognostic value

Background. Endothelial-derived microparticles (EDMPs) and platelet-derived microparticles (PDMPs) have been reported to be increasing in various diseases including malignant diseases. Here, we investigated whether these MPs may be useful biomarkers for predicting lung cancer (LC) disease status, cell type, or metastasis. Methods and Results. One hundred and thirty LC patients were prospectively enrolled into the study between April 2011 and February 2012. Flow cytometric analysis demonstrated that the circulating levels of platelet-derived activated MPs (PDAc-MPs), platelet-derived apoptotic MPs (PDAp-MPs), endothelial-derived activated MPs (EDAc-MPs), and endothelial-derived apoptotic MPs (EDAp-MPs) were significantly higher in LC patients than in 30 age- and gender-matched normal control subjects (all P < 0.05). Additionally, circulating level of PDAc-MPs was significantly lower (P = 0.031), whereas the circulating levels of the other three biomarkers did not differ (all P > 0.1) in early stage versus late stage LC patients. Furthermore, the circulating levels of the four types of MPs did not differ among patients with different disease statuses (i.e., disease controlled, disease progression, and disease without treatment, i.e., fresh case) (all P > 0.2) or between patients with or without LC metastasis (all P > 0.5). Moreover, only the circulating level of EDAp-MPs was significantly associated with the different cell types (i.e., squamous cell carcinoma, adenocarcinoma, and small cell carcinoma) of LC (P = 0.045). Conclusion. Circulating MP levels are significantly increased in LC patients as compared with normal subjects. Among the MPs, only an increased level of EDAp-MPs was significantly associated with different LC cell types.

Screening guidelines for non-AIDS defining cancers in HIV-infected individuals

PURPOSE OF REVIEW

The growing burden of non-AIDS defining malignancies (non-ADMs) among people living with HIV/AIDS (PLWHA) highlights the need for cancer prevention and early detection. In this article, we propose screening guidelines for non-ADMs in PLWHA.

RECENT FINDINGS

A number of recent findings may help direct cancer screening guidelines in PLWHA. Screening for lung cancer with low-dose helical chest computerized tomography (LDCT) in the National Lung Screening Trial data demonstrated a decrease in lung cancer and all-cause mortality. Recent studies have demonstrated a favorable experience among PLWHA with liver transplantation. Overdiagnosis is common with breast and prostate cancer screening. Anal cancer rates were substantially higher for HIV-infected MSM, other men and women than for HIV-uninfected individuals.

SUMMARY

Screening recommendations for the general population can be applied to PLWHA patients for breast, colon and prostate cancer. Screening for lung cancer with LDCT could be considered in PLWHA at risk. American Association for the Study of Liver Diseases screening recommendations with biennial ultrasonography may be applied to at-risk PLWHA for hepatocellular carcinoma. All HIV-infected adults should be offered anal cancer screening as part of clinical care at specialized centres.

Chest X-ray screening for lung cancer: overdiagnosis, endpoints, and randomized population trials

Publication of the National Lung Screening Trial (NLST) generated excitement by concluding that CT screening reduces lung cancer mortality when compared to chest X-ray (CXR) screening. In contrast, CXR screening has long been considered to be ineffective. This is because randomized population trials (RPTs) have failed to demonstrate significant mortality reductions in populations randomized to CXR screening. While these studies demonstrate that CXR screening is associated with significant survival advantages, these advantages have been widely interpreted as spurious, due to the inference that CXR screening leads to substantial lung cancer overdiagnosis. Indeed, the reality of the overdiagnosis hypothesis is the only alternative to the conclusion that CXR screening was effective in these trials and that survival more accurately reflected the benefit of CXR screening than mortality. Mortality comparisons would be biased if randomization fails to create comparison groups with an equal probability of mortality from the target cancer. The objective of this manuscript is to review existing RPTs on CXR screening for lung cancer, and to analyze which endpoint most accurately reflects screening efficacy. We conclude that the evidence supports that CXR screening is superior to no screening, and the magnitude of overdiagnosis is minimal in the context of CXR screening.

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

BACKGROUND

Lung cancer is by far the major cause of cancer deaths largely because in the majority of patients it is at an advanced stage at the time it is discovered, when curative treatment is no longer feasible. This article examines the data regarding the ability of screening to decrease the number of lung cancer deaths.

METHODS

A systematic review was conducted of controlled studies that address the effectiveness of methods of screening for lung cancer.

RESULTS

Several large randomized controlled trials (RCTs), including a recent one, have demonstrated that screening for lung cancer using a chest radiograph does not reduce the number of deaths from lung cancer. One large RCT involving low-dose CT (LDCT) screening demonstrated a significant reduction in lung cancer deaths, with few harms to individuals at elevated risk when done in the context of a structured program of selection, screening, evaluation, and management of the relatively high number of benign abnormalities. Whether other RCTs involving LDCT screening are consistent is unclear because data are limited or not yet mature.

CONCLUSIONS

Screening is a complex interplay of selection (a population with sufficient risk and few serious comorbidities), the value of the screening test, the interval between screening tests, the availability of effective treatment, the risk of complications or harms as a result of screening, and the degree with which the screened individuals comply with screening and treatment recommendations. Screening with LDCT of appropriate individuals in the context of a structured process is associated with a significant reduction in the number of lung cancer deaths in the screened population. Given the complex interplay of factors inherent in screening, many questions remain on how to effectively implement screening on a broader scale.

Lung cancer screening: past, present and future

Lung cancer is the leading cause of cancer death for men and women. Most lung cancer cases are diagnosed at an advanced stage, when cure is no longer an option; this heavily influences mortality. Historically, attempts at lung cancer screening using chest x-rays and sputum cytology have failed to influence lung cancer mortality. However, the recent National Lung Screening Trial demonstrated that low-dose computed tomography screening for lung cancer decreases mortality. This article outlines the history of lung cancer screening, the current state of screening and possible future adjuncts to screening.

Moving beyond the national lung screening trial: discussing strategies for implementation of lung cancer screening programs

The National Lung Screening Trial (NLST) has sparked new interest in the adoption of lung cancer screening using low-dose computed tomography (LDCT). If adopted at a national level, LDCT screening may prevent approximately 18,000 lung cancer deaths per year, potentially constituting a high-value public health intervention. Before incorporating LDCT screening into practice, health care institutions need to consider the risks associated with LDCT screening and the impact of LDCT screening on health care costs, as well as other remaining areas of uncertainty, including the unknown cost-effectiveness of LDCT screening. This article will review the benefits and risks of LDCT screening in light of the results of the NLST and other randomized trials, it will discuss the additional health care costs associated with LDCT screening from the perspective of health care payers, and it will examine the published cost-effectiveness analyses of LDCT screening. A subsequent discussion highlights guideline recommendations for implementation strategies, the goals of which are to ensure that those eligible for LDCT screening derive the benefits while minimizing the risks of screening and avoiding an unnecessary escalation in screening-related costs. The article concludes by endorsing the use of LDCT screening in institutions capable of responsible implementation of screening in both medical and economic terms. The key elements of responsible implementation include the development of standardized screening practices, careful selection of screening candidates, and the creation of prospective registries that will mitigate current areas of uncertainty regarding LDCT screening.

The Diagnosis and Attribution of Asbestos-related Diseases in an Australian Context: Report of the Adelaide Workshop on Asbestos-related Diseases. October 6–7, 2000

Predictions of future cases of mesothelioma in Australia to the year 2020 are in the order of a total of 10,000 new cases. Compensation claims are testing the attribution in a particular case between occupational asbestos exposure and lung cancer. The cost of the problem necessitates clarifying and standardizing the criteria for a confident diagnosis of asbestos-related disease. The possibility of differences in criteria that determine attribution of asbestos to a disease prompted a consensus meeting of pathologists, epidemiologists, physicians, oncologists, radiologists, and others to define current thinking and to agree on an Australian document based on the scientific evidence for establishing diagnoses and attribution data of asbestos-related diseases in Australia. The participants' findings are reported.

Screening for lung cancer

BACKGROUND

This is an updated version of the original review published in The Cochrane Library in 1999 and updated in 2004 and 2010. Population-based screening for lung cancer has not been adopted in the majority of countries. However it is not clear whether sputum examinations, chest radiography or newer methods such as computed tomography (CT) are effective in reducing mortality from lung cancer.

OBJECTIVES

To determine whether screening for lung cancer, using regular sputum examinations, chest radiography or CT scanning of the chest, reduces lung cancer mortality.

SEARCH METHODS

We searched electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5), MEDLINE (1966 to 2012), PREMEDLINE and EMBASE (to 2012) and bibliographies. We handsearched the journal Lung Cancer (to 2000) and contacted experts in the field to identify published and unpublished trials.

SELECTION CRITERIA

Controlled trials of screening for lung cancer using sputum examinations, chest radiography or chest CT.

DATA COLLECTION AND ANALYSIS

We performed an intention-to-screen analysis. Where there was significant statistical heterogeneity, we reported risk ratios (RRs) using the random-effects model. For other outcomes we used the fixed-effect model.

MAIN RESULTS

We included nine trials in the review (eight randomised controlled studies and one controlled trial) with a total of 453,965 subjects. In one large study that included both smokers and non-smokers comparing annual chest x-ray screening with usual care there was no reduction in lung cancer mortality (RR 0.99, 95% CI 0.91 to 1.07). In a meta-analysis of studies comparing different frequencies of chest x-ray screening, frequent screening with chest x-rays was associated with an 11% relative increase in mortality from lung cancer compared with less frequent screening (RR 1.11, 95% CI 1.00 to 1.23); however several of the trials included in this meta-analysis had potential methodological weaknesses. We observed a non-statistically significant trend to reduced mortality from lung cancer when screening with chest x-ray and sputum cytology was compared with chest x-ray alone (RR 0.88, 95% CI 0.74 to 1.03). There was one large methodologically rigorous trial in high-risk smokers and ex-smokers (those aged 55 to 74 years with ≥ 30 pack-years of smoking and who quit ≤ 15 years prior to entry if ex-smokers) comparing annual low-dose CT screening with annual chest x-ray screening; in this study the relative risk of death from lung cancer was significantly reduced in the low-dose CT group (RR 0.80, 95% CI 0.70 to 0.92).

AUTHORS' CONCLUSIONS

The current evidence does not support screening for lung cancer with chest radiography or sputum cytology. Annual low-dose CT screening is associated with a reduction in lung cancer mortality in high-risk smokers but further data are required on the cost effectiveness of screening and the relative harms and benefits of screening across a range of different risk groups and settings.

Results of initial low-dose computed tomographic screening for lung cancer

BACKGROUND

Lung cancer is the largest contributor to mortality from cancer. The National Lung Screening Trial (NLST) showed that screening with low-dose helical computed tomography (CT) rather than with chest radiography reduced mortality from lung cancer. We describe the screening, diagnosis, and limited treatment results from the initial round of screening in the NLST to inform and improve lung-cancer-screening programs.

METHODS

At 33 U.S. centers, from August 2002 through April 2004, we enrolled asymptomatic participants, 55 to 74 years of age, with a history of at least 30 pack-years of smoking. The participants were randomly assigned to undergo annual screening, with the use of either low-dose CT or chest radiography, for 3 years. Nodules or other suspicious findings were classified as positive results. This article reports findings from the initial screening examination.

RESULTS

A total of 53,439 eligible participants were randomly assigned to a study group (26,715 to low-dose CT and 26,724 to chest radiography); 26,309 participants (98.5%) and 26,035 (97.4%), respectively, underwent screening. A total of 7191 participants (27.3%) in the low-dose CT group and 2387 (9.2%) in the radiography group had a positive screening result; in the respective groups, 6369 participants (90.4%) and 2176 (92.7%) had at least one follow-up diagnostic procedure, including imaging in 5717 (81.1%) and 2010 (85.6%) and surgery in 297 (4.2%) and 121 (5.2%). Lung cancer was diagnosed in 292 participants (1.1%) in the low-dose CT group versus 190 (0.7%) in the radiography group (stage 1 in 158 vs. 70 participants and stage IIB to IV in 120 vs. 112). Sensitivity and specificity were 93.8% and 73.4% for low-dose CT and 73.5% and 91.3% for chest radiography, respectively.

CONCLUSIONS

The NLST initial screening results are consistent with the existing literature on screening by means of low-dose CT and chest radiography, suggesting that a reduction in mortality from lung cancer is achievable at U.S. screening centers that have staff experienced in chest CT. (Funded by the National Cancer Institute; NLST ClinicalTrials.gov number, NCT00047385.).

American Cancer Society lung cancer screening guidelines

Findings from the National Cancer Institute's National Lung Screening Trial established that lung cancer mortality in specific high-risk groups can be reduced by annual screening with low-dose computed tomography. These findings indicate that the adoption of lung cancer screening could save many lives. Based on the results of the National Lung Screening Trial, the American Cancer Society is issuing an initial guideline for lung cancer screening. This guideline recommends that clinicians with access to high-volume, high-quality lung cancer screening and treatment centers should initiate a discussion about screening with apparently healthy patients aged 55 years to 74 years who have at least a 30-pack-year smoking history and who currently smoke or have quit within the past 15 years. A process of informed and shared decision-making with a clinician related to the potential benefits, limitations, and harms associated with screening for lung cancer with low-dose computed tomography should occur before any decision is made to initiate lung cancer screening. Smoking cessation counseling remains a high priority for clinical attention in discussions with current smokers, who should be informed of their continuing risk of lung cancer. Screening should not be viewed as an alternative to smoking cessation.

Computed tomography screening for lung cancer: has it finally arrived? Implications of the national lung screening trial

The National Lung Screening Trial (NLST) has provided compelling evidence of the efficacy of lung cancer screening using low-dose helical computed tomography (LDCT) to reduce lung cancer mortality. The NLST randomized 53,454 older current or former heavy smokers to receive LDCT or chest radiography (CXR) for three annual screens. Participants were observed for a median of 6.5 years for outcomes. Vital status was available in more than 95% of participants. LDCT was positive in 24.2% of screens, compared with 6.9% of CXRs; more than 95% of all positive LDCT screens were not associated with lung cancer. LDCT detected more than twice the number of early-stage lung cancers and resulted in a stage shift from advanced to early-stage disease. Complications of LDCT screening were minimal. Lung cancer-specific mortality was reduced by 20% relative to CXR; all-cause mortality was reduced by 6.7%. The major harms of LDCT are radiation exposure, high false-positive rates, and the potential for overdiagnosis. This review discusses the risks and benefits of LDCT screening as well as an approach to LDCT implementation that incorporates systematic screening practice with smoking cessation programs and offers opportunities for better determination of appropriate risk cohorts for screening and for better diagnostic prediction of lung cancer in the setting of screen-detected nodules. The challenges of implementation are considered for screening programs, for primary care clinicians, and across socioeconomic strata. Considerations for future research to complement imaging-based screening to reduce the burden of lung cancer are discussed.

Lung cancer screening: from imaging to biomarker

Despite several decades of intensive effort to improve the imaging techniques for lung cancer diagnosis and treatment, primary lung cancer is still the number one cause of cancer death in the United States and worldwide. The major causes of this high mortality rate are distant metastasis evident at diagnosis and ineffective treatment for locally advanced disease. Indeed, approximately forty percent of newly diagnosed lung cancer patients have distant metastasis. Currently, the only potential curative therapy is surgical resection of early stage lung cancer. Therefore, early detection of lung cancer could potentially increase the chance of cure by surgery and underlines the importance of screening and detection of lung cancer. In the past fifty years, screening of lung cancer by chest X-Ray (CXR), sputum cytology, computed tomography (CT), fluorescence endoscopy and low-dose spiral CT (LDCT) has not improved survival except for the recent report in 2010 by the National Lung Screening Trial (NLST), which showed a 20 percent mortality reduction in high risk participants screened with LDCT compared to those screened with CXRs. Furthermore, serum biomarkers for detection of lung cancer using free circulating DNA and RNA, exosomal microRNA, circulating tumor cells and various lung cancer specific antigens have been studied extensively and novel screening methods are being developed with encouraging results. The history of lung cancer screening trials using CXR, sputum cytology and LDCT, as well as results of trials involving various serum biomarkers, are reviewed herein.

From randomized trials to the clinic: is it time to implement individual lung-cancer screening in clinical practice? A multidisciplinary statement from French experts on behalf of the French intergroup (IFCT) and the groupe d'Oncologie de langue francaise (GOLF)

Background

Despite advances in cancer therapy, mortality is still high except in early-stage tumors, and screening remains a challenge. The randomized National Lung Screening Trial (NLST), comparing annual low-dose computed tomography (LDCT) and chest X-rays, revealed a 20% decrease in lung-cancer-specific mortality. These results raised numerous questions. The French intergroup for thoracic oncology and the French-speaking oncology group convened an expert group to provide a coherent outlook on screening modalities in France.

Methods

A literature review was carried out and transmitted to the expert group, which was divided into three workshops to tackle specific questions, with responses presented in a plenary session. A writing committee drafted this article.

Results

The multidisciplinary group favored individual screening in France, when carried out as outlined in this article and after informing subjects of the benefits and risks. The target population involves subjects aged 55–74 years, who are smokers or have a 30 pack-year smoking history. Subjects should be informed about the benefits of quitting. Screening should involve LDCT scanning with specific modalities. Criteria for CT positivity and management algorithms for positive examinations are given.

Conclusions

Individual screening requires rigorous assessment and precise research in order to potentially develop a lung-cancer screening policy.

Lung cancer screening: making the transition from research to clinical practice

PURPOSE OF REVIEW

The purpose of this review is to examine the literature on lung cancer screening with an emphasis on the prevalence of cancer in screen-detected nodules. On the basis of the evidence, we will then develop a practical approach to screen-detected lung nodules.

RECENT FINDINGS

The first large randomized controlled trial using low-dose computed tomography (LDCT) found that persons undergoing three annual screening examinations with LDCT had a 20% relative reduction in lung cancer mortality as compared with those screened with annual chest X-rays. The probability of cancer in screen-detected nodules depends on their size and whether the nodules are detected on prevalence or incidence screens. The probability of cancer in screen-detected nodules ranges from 2.4 to 5.2%. Management strategies for screen-detected nodules that have been used successfully include careful observation using serial CT imaging, CT-guided fine needle biopsy, and surgery in carefully selected cases. The most frequently used strategies involve serial CT imaging and CT-guided biopsy for larger nodules and those that demonstrate growth on follow-up.

SUMMARY

There is now evidence that LDCT in carefully selected high-risk populations can lead to better outcomes but the cost effectiveness of mass screening with LDCT is still unknown. Only patients at high risk for cancer should be screened.

The impact of National Death Index linkages on population-based cancer survival rates in the United States

BACKGROUND

In order to ensure accurate survival estimates, population-based cancer registries must ascertain all, or nearly all, patients diagnosed with cancer in their catchment area, and obtain complete follow-up information on all deaths that occurred among registered cancer patients. In the US, linkage with state death records may not be sufficient to ascertain all deaths. Since 1979, all state vital statistics offices have reported their death certificate information to the National Death Index (NDI).

OBJECTIVE

This study was designed to measure the impact of linkage with the NDI on population-based relative and cancer cause-specific survival rates in the US.

METHODS

Central cancer registry records for patients diagnosed 1993-1995 from California, Colorado, and Idaho were linked with death certificate information (deaths 1993-2004) from their individual state vital statistics offices and with the NDI. Two databases were created: one contained incident records with deceased patients linked only to state death records and the second database contained incident records with deceased patients linked to both state death records and the NDI. Survival estimates and 95% confidence intervals from each database were compared by state and primary site category.

RESULTS

At 60 months follow-up, 42.1-48.1% of incident records linked with state death records and an additional 0.7-3.4% of records linked with the NDI. Survival point estimates from the analysis without NDI were not contained within the corresponding 95% CIs from the NDI augmented analysis for all sites combined and colorectal, pancreas, lung and bronchus, breast, prostate, non-Hodgkin lymphoma, and Kaposi sarcoma cases in all 3 states using relative survival methods. Additional combinations of state and primary site had significant survival estimate differences, which differed by method (relative versus cause-specific survival).

CONCLUSION

To ensure accurate population-based cancer survival rates, linkage with the National Death Index to ascertain out of state and late registered deaths is a necessary process for US central cancer registries.

CT scan screening for lung cancer: risk factors for nodules and malignancy in a high-risk urban cohort

Background

Low-dose computed tomography (CT) for lung cancer screening can reduce lung cancer mortality. The National Lung Screening Trial reported a 20% reduction in lung cancer mortality in high-risk smokers. However, CT scanning is extremely sensitive and detects non-calcified nodules (NCNs) in 24–50% of subjects, suggesting an unacceptably high false-positive rate. We hypothesized that by reviewing demographic, clinical and nodule characteristics, we could identify risk factors associated with the presence of nodules on screening CT, and with the probability that a NCN was malignant.

Methods

We performed a longitudinal lung cancer biomarker discovery trial (NYU LCBC) that included low-dose CT-screening of high-risk individuals over 50 years of age, with more than 20 pack-year smoking histories, living in an urban setting, and with a potential for asbestos exposure. We used case-control studies to identify risk factors associated with the presence of nodules (n = 625) versus no nodules (n = 557), and lung cancer patients (n = 30) versus benign nodules (n = 128).

Results

The NYU LCBC followed 1182 study subjects prospectively over a 10-year period. We found 52% to have NCNs >4 mm on their baseline screen. Most of the nodules were stable, and 9.7% of solid and 26.2% of sub-solid nodules resolved. We diagnosed 30 lung cancers, 26 stage I. Three patients had synchronous primary lung cancers or multifocal disease. Thus, there were 33 lung cancers: 10 incident, and 23 prevalent. A sub-group of the prevalent group were stable for a prolonged period prior to diagnosis. These were all stage I at diagnosis and 12/13 were adenocarcinomas.

Conclusions

NCNs are common among CT-screened high-risk subjects and can often be managed conservatively. Risk factors for malignancy included increasing age, size and number of nodules, reduced FEV1 and FVC, and increased pack-years smoking. A sub-group of screen-detected cancers are slow-growing and may contribute to over-diagnosis and lead-time biases.

Chapter 13: CISNET lung models: comparison of model assumptions and model structures

Sophisticated modeling techniques can be powerful tools to help us understand the effects of cancer control interventions on population trends in cancer incidence and mortality. Readers of journal articles are, however, rarely supplied with modeling details. Six modeling groups collaborated as part of the National Cancer Institute's Cancer Intervention and Surveillance Modeling Network (CISNET) to investigate the contribution of U.S. tobacco-control efforts toward reducing lung cancer deaths over the period 1975-2000. The six models included in this monograph were developed independently and use distinct, complementary approaches toward modeling the natural history of lung cancer. The models used the same data for inputs, and agreed on the design of the analysis and the outcome measures. This article highlights aspects of the models that are most relevant to similarities of or differences between the results. Structured comparisons can increase the transparency of these complex models.

The role and potential of imaging in COPD

Chronic obstructive pulmonary disease is a heterogeneous condition of the lungs and body. Techniques in chest imaging and quantitative image analysis provide novel in vivo insight into the disease and potentially examine divergent responses to therapy. This article reviews the strengths and limitations of the leading imaging techniques: computed tomography, magnetic resonance imaging, positron emission tomography, and optical coherence tomography. Following an explanation of the technique, each section details some of the useful information obtained with these examinations. Future clinical care and investigation will likely include some combination of these imaging modalities and more standard assessments of disease severity.

Benefits and harms of CT screening for lung cancer: a systematic review

CONTEXT

Lung cancer is the leading cause of cancer death. Most patients are diagnosed with advanced disease, resulting in a very low 5-year survival. Screening may reduce the risk of death from lung cancer.

OBJECTIVE

To conduct a systematic review of the evidence regarding the benefits and harms of lung cancer screening using low-dose computed tomography (LDCT). A multisociety collaborative initiative (involving the American Cancer Society, American College of Chest Physicians, American Society of Clinical Oncology, and National Comprehensive Cancer Network) was undertaken to create the foundation for development of an evidence-based clinical guideline.

DATA SOURCES

MEDLINE (Ovid: January 1996 to April 2012), EMBASE (Ovid: January 1996 to April 2012), and the Cochrane Library (April 2012).

STUDY SELECTION

Of 591 citations identified and reviewed, 8 randomized trials and 13 cohort studies of LDCT screening met criteria for inclusion. Primary outcomes were lung cancer mortality and all-cause mortality, and secondary outcomes included nodule detection, invasive procedures, follow-up tests, and smoking cessation.

DATA EXTRACTION

Critical appraisal using predefined criteria was conducted on individual studies and the overall body of evidence. Differences in data extracted by reviewers were adjudicated by consensus.

RESULTS

Three randomized studies provided evidence on the effect of LDCT screening on lung cancer mortality, of which the National Lung Screening Trial was the most informative, demonstrating that among 53,454 participants enrolled, screening resulted in significantly fewer lung cancer deaths (356 vs 443 deaths; lung cancer−specific mortality, 274 vs 309 events per 100,000 person-years for LDCT and control groups, respectively; relative risk, 0.80; 95% CI, 0.73-0.93; absolute risk reduction, 0.33%; P = .004). The other 2 smaller studies showed no such benefit. In terms of potential harms of LDCT screening, across all trials and cohorts, approximately 20% of individuals in each round of screening had positive results requiring some degree of follow-up, while approximately 1% had lung cancer. There was marked heterogeneity in this finding and in the frequency of follow-up investigations, biopsies, and percentage of surgical procedures performed in patients with benign lesions. Major complications in those with benign conditions were rare.

CONCLUSION

Low-dose computed tomography screening may benefit individuals at an increased risk for lung cancer, but uncertainty exists about the potential harms of screening and the generalizability of results.

Screening for lung cancer

The authors give an overview about the novel results and shifting paradigm of lung cancer screening. They also summarize the results of previous and most recent clinical trials, which re-directed the international interest on lung cancer screening. Orv. Hetil., 2012, 153, 904–907.

A multiplexed serum biomarker immunoassay panel discriminates clinical lung cancer patients from high-risk individuals found to be cancer-free by CT screening

INTRODUCTION

Clinical decision making in the setting of computed tomography (CT) screening could benefit from accessible biomarkers that help predict the level of lung cancer risk in high-risk individuals with indeterminate pulmonary nodules.

METHODS

To identify candidate serum biomarkers, we measured 70 cancer-related proteins by Luminex xMAP (Luminex Corporation) multiplexed immunoassays in a training set of sera from 56 patients with biopsy-proven primary non-small-cell lung cancer and 56 age-, sex-, and smoking-matched CT-screened controls.

RESULTS

We identified a panel of 10 serum biomarkers-prolactin, transthyretin, thrombospondin-1, E-selectin, C-C motif chemokine 5, macrophage migration inhibitory factor, plasminogen activator inhibitor, receptor tyrosine-protein kinase, erbb-2, cytokeratin fragment 21.1, and serum amyloid A-that distinguished lung cancer patients from controls with an estimated balanced accuracy (average of sensitivity and specificity) of 76.0 ± 3.8% from 20-fold internal cross-validation. We then iteratively evaluated this model in an independent test and verification case/control studies confirming the initial classification performance of the panel. The classification performance of the 10-biomarker panel was also analytically validated using enzyme-linked immunosorbent assays in a second independent case/control population, further validating the robustness of the panel.

CONCLUSIONS

The performance of this 10-biomarker panel-based model was 77.1% sensitivity/76.2% specificity in cross-validation in the expanded training set, 73.3% sensitivity/93.3% specificity (balanced accuracy 83.3%) in the blinded verification set with the best discriminative performance in stage I/II cases: 85% sensitivity (balanced accuracy 89.2%). Importantly, the rate of misclassification of CT-screened controls was not different in most control subgroups with or without airflow obstruction or emphysema or pulmonary nodules. These biomarkers have potential to aid in the early detection of lung cancer and more accurate interpretation of indeterminate pulmonary nodules detected by CT screening.

Lung cancer screening practices of primary care physicians: results from a national survey

PURPOSE

Although current practice guidelines do not recommend screening asymptomatic patients for lung cancer, physicians may still order lung cancer screening tests. No recent national survey of health care professionals has focused on lung cancer screening. In this study, we examined the lung cancer screening practices of US primary care physicians and characteristics of those who order lung cancer screening tests.

METHODS

We conducted a nationally representative survey of practicing primary care physicians in 2006-2007. Mailed questionnaires assessed the physicians' knowledge of lung cancer screening guidelines, beliefs about the effectiveness of screening tests, and ordering of screening chest radiograph, low-dose spiral computed tomography, or sputum cytology in the past 12 months. Clinical vignettes were used to assess the physicians' intentions to screen asymptomatic 50-year-old patients with varying smoking histories for lung cancer.

RESULTS

A total of 962 family physicians, general practitioners, and general internists completed questionnaires (cooperation rate = 76.8%). Overall, 38% had ordered no lung cancer screening tests; 55% had ordered chest radiograph, 22% low-dose spiral computed tomography, and less than 5% sputum cytology. In multivariate modeling, physicians were more likely to have ordered lung cancer screening tests if they believed that expert groups recommend lung cancer screening or that screening tests are effective; if they would recommend screening for asymptomatic patients, including patients without substantial smoking exposure; and if their patients had asked them about screening.

CONCLUSIONS

Primary care physicians in the United States frequently order lung cancer screening tests for asymptomatic patients, even though expert groups do not recommend it. Primary care physicians and patients need more information about lung cancer screening's evidence base, guidelines, potential harms, and costs to avert inappropriate ordering.

Comparing the benefits of screening for breast cancer and lung cancer using a novel natural history model

To estimate the impact of early detection of cancer, knowledge of how quickly primary tumors grow and at what size they shed lethal metastases is critical. We developed a natural history model of cancer to estimate the probability of disease-specific cure as a function of tumor size, the tumor volume doubling time (TVDT), and disease-specific mortality reduction achievable by screening. The model was applied to non-small-cell lung carcinoma (NSCLC) and invasive ductal carcinoma (IDC), separately. Model parameter estimates were based on Surveillance Epidemiology and End Results (SEER) cancer registry datasets and validated on screening trials. Compared to IDC, NSCLC is estimated to have a lower probability of disease-specific cure at the same detected tumor size, shed lethal metastases at smaller sizes (median: 19 mm for IDC versus 8 mm for NSCLC), have a TVDT that is almost half as long (median: 252 days for IDC versus 134 days for NSCLC). Consequently, NSCLC is associated with a lower mortality reduction from screening at the same screen detection threshold and screening interval. In summary, using a similar natural history model of cancer, we quantify the disease-specific curability attributable to screening for breast cancer, and separately lung cancer, in terms of the TVDT and onset of lethal metastases.

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.

Measuring mortality reductions in cancer screening trials

Randomized trials involving large numbers of people and long follow-up have helped measure the mortality reductions achievable by screening for cancer. However, in many of these trials, the reported reductions have been modest. Part of the reason is the inappropriate way the reductions have been calculated. Analyses have largely ignored the fact that there is a time window in the first several years after screening begins in which there cannot be a sizable mortality reduction, followed by one in which the reductions become evident, and-unless screening is continued-a third window in which mortality rates in the screened group revert to those in the unscreened group. This review uses time-specific mortality ratios to address the timing and extent of the reductions achieved in trials of screening for prostate, breast, and colorectal cancer. The author finds that the mortality reductions reported in the literature have substantially underestimated what might be accomplished with continued screening. The natural history of the disease, the frequency of screening, and the duration of follow-up determine the time patterns in the reductions observed in trials. Without appropriate analyses, results from cancer screening trials will be distorted.

Exploring the uncertainties of early detection results: model-based interpretation of mayo lung project

BACKGROUND

The Mayo Lung Project (MLP), a randomized controlled clinical trial of lung cancer screening conducted between 1971 and 1986 among male smokers aged 45 or above, demonstrated an increase in lung cancer survival since the time of diagnosis, but no reduction in lung cancer mortality. Whether this result necessarily indicates a lack of mortality benefit for screening remains controversial. A number of hypotheses have been proposed to explain the observed outcome, including over-diagnosis, screening sensitivity, and population heterogeneity (initial difference in lung cancer risks between the two trial arms). This study is intended to provide model-based testing for some of these important arguments.

METHOD

Using a micro-simulation model, the MISCAN-lung model, we explore the possible influence of screening sensitivity, systematic error, over-diagnosis and population heterogeneity.

RESULTS

Calibrating screening sensitivity, systematic error, or over-diagnosis does not noticeably improve the fit of the model, whereas calibrating population heterogeneity helps the model predict lung cancer incidence better.

CONCLUSIONS

Our conclusion is that the hypothesized imperfection in screening sensitivity, systematic error, and over-diagnosis do not in themselves explain the observed trial results. Model fit improvement achieved by accounting for population heterogeneity suggests a higher risk of cancer incidence in the intervention group as compared with the control group.

The National Lung Screening Trial: overview and study design

The National Lung Screening Trial (NLST) is a randomized multicenter study comparing low-dose helical computed tomography (CT) with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer, which is the leading cause of cancer-related death in the United States. Five-year survival rates approach 70% with surgical resection of stage IA disease; however, more than 75% of individuals have incurable locally advanced or metastatic disease, the latter having a 5-year survival of less than 5%. It is plausible that treatment should be more effective and the likelihood of death decreased if asymptomatic lung cancer is detected through screening early enough in its preclinical phase. For these reasons, there is intense interest and intuitive appeal in lung cancer screening with low-dose CT. The use of survival as the determinant of screening effectiveness is, however, confounded by the well-described biases of lead time, length, and overdiagnosis. Despite previous attempts, no test has been shown to reduce lung cancer mortality, an endpoint that circumvents screening biases and provides a definitive measure of benefit when assessed in a randomized controlled trial that enables comparison of mortality rates between screened individuals and a control group that does not undergo the screening intervention of interest. The NLST is such a trial. The rationale for and design of the NLST are presented.

U.S. primary care physicians' lung cancer screening beliefs and recommendations

BACKGROUND

No high-quality study to date has shown that screening reduces lung cancer mortality, and expert groups do not recommend screening for asymptomatic individuals. Nevertheless, lung cancer screening tests are available in the U.S., and primary care physicians (PCPs) may have a role in recommending them to patients.

PURPOSE

This study describes U.S. PCPs' beliefs about and recommendations for lung cancer screening and examines characteristics of PCPs who recommend screening.

METHODS

A nationally representative survey of practicing PCPs was conducted in 2006-2007. Mailed questionnaires were used to assess PCPs' beliefs about lung cancer screening guidelines and the effectiveness of screening tests and to determine whether PCPs would recommend screening for asymptomatic patients. Data were analyzed in 2009.

RESULTS

Nine hundred sixty-two PCPs completed the survey (absolute response rate=70.6%; cooperation rate=76.8%). One quarter said that major guidelines support lung cancer screening. Two thirds said that low-radiation dose spiral computed tomography (LDCT) screening is very or somewhat effective in reducing lung cancer mortality in current smokers; LDCT was perceived as more effective than chest x-ray or sputum cytology. Responding to vignettes describing asymptomatic patients of varying smoking exposure, 67% of PCPs recommended lung cancer screening for at least one of the vignettes. Most PCPs recommending screening said they would use chest x-ray; up to 26% would use LDCT. In adjusted analyses, PCPs' beliefs and practice style were strongly associated with their lung cancer screening recommendations.

CONCLUSIONS

Many PCPs' lung cancer screening beliefs and recommendations are inconsistent with current evidence and guidelines. Provider education regarding the evidence base and guideline content of lung cancer screening is indicated.

Volunteer effect and compromised randomization in the Mayo Project of screening for lung cancer

It has been confirmed recently that the volunteer effect in lung cancer screening is characterized by higher lung cancer mortality risk in self-selected screening participants. The Mayo Lung Project, the most influential trial of screening for lung cancer ever completed, was conducted in nonvolunteer Mayo Clinic outpatients, with a peculiar study design that rendered the randomization vulnerable to the volunteer effect. Of all nonvolunteers randomized in the Mayo Lung Project, only those allocated in the screened group were asked consent to participate in the trial. The final Mayo Lung Project report stated that 655 randomized nonvolunteers refused screening and were excluded from the study, thus documenting violation of the rule that no selection should occur after randomization. The long-term follow-up of the Mayo Lung Project showed an enigmatic result which has never been explained: the lung cancer mortality was 13% higher in the screening intervention group than in the control group [4.4 (95% CI 3.9-4.9) vs. 3.9 (95% CI 3.5-4.4) per 1,000 person-years; P = 0.09]. Such overrepresented mortality is consistent with the volunteer effect and supports the concept that the Mayo Lung Project randomization was compromised by the post-randomization self-selection of participant nonvolunteers.

Can lung cancer screening by computed tomography be effective in areas with endemic histoplasmosis?

OBJECTIVE

Low-dose chest computed tomography (CT) is being evaluated in several national trials as a screening modality for the early detection of lung cancer. The goal of the present study was to determine whether lung cancer screening could be done while minimizing the number of benign biopsy specimens taken in an area endemic for histoplasmosis.

METHODS

The subjects were recruited by letters mailed to area physicians and local advertisement. The inclusion criteria were age older than 50 years and at least a 20 pack-year smoking history. The exclusion criteria were symptoms suggestive of lung cancer or a history of malignancy in the previous 5 years. The participants completed a questionnaire and underwent a chest CT scan at baseline and annually for 5 years. The management of positive screening results was determined using a defined algorithm: annual follow-up CT scan for nodules less than 5 mm; 6-month follow-up CT scan for nodules 5 to 7 mm; review by our multidisciplinary tumor board for nodules 8 to 12 mm; and biopsy for nodules greater than 12 mm.

RESULTS

A total of 132 patients were recruited. Of the 132 patients, 61% had positive baseline CT findings and 22% had positive findings on the annual CT scans. Six cancers were detected. Of these 6 patients, 5 had stage I disease and underwent lobectomy, and 1 had stage IIIA disease and underwent induction chemotherapy and radiotherapy followed by lobectomy. All patients were alive and disease free at a mean follow-up of 41.7 ± 18.6 months. No biopsies were performed for benign lesions. Also, no cancers were missed when the protocol was followed.

CONCLUSIONS

Screening with CT can be done effectively in an area endemic for histoplasmosis while minimizing benign biopsies.

Cancer screening trials: nuts and bolts

The most rigorous and valid approach to evaluating cancer screening modalities is the randomized controlled trial (RCT). RCTs are major undertakings and the intricacies of trial design, operations, and management are generally underappreciated by the typical researcher. The purpose of this article is to inform the reader of the "nuts and bolts" of designing and conducting cancer screening RCTs. Following a brief introduction as to why RCTs are critical in evaluating screening modalities, we discuss design considerations, including the choice of design type and duration of follow-up. We next present an approach to sample-size calculations. We then discuss aspects of trial implementation, including recruitment, randomization, and data management. A discussion of commonly employed data analyses comes next, and includes methods for the primary analysis (comparison of cause-specific mortality rates between the screened and control arms for the cancer of interest), as well as for secondary endpoints such as sensitivity. We follow with a discussion of sequential monitoring and interim analysis techniques, which are used to examine the primary outcome while the trial is ongoing. We close with thoughts on lessons learned from past cancer screening RCTs and provide recommendations for future trials. Throughout the presentation we illustrate topics with examples from completed or ongoing RCTs, including the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and the National Lung Screening Trial (NLST).