Prediction of risk of lung cancer in populations and in pulmonary nodules: Significant progress to drive changes in paradigms

The ability to estimate the risk of lung cancer is important in three common clinical scenarios: the management of pulmonary nodules, the selection of people for screening with computed tomography and in the early identification of symptomatic disease. The risk prediction models that have been developed have similar themes owing to the strongest risk factors dominating the model. In the management of pulmonary nodules, there is a need to ensure that models reliably predict the chance of malignancy by performing validation studies in the population in which the models will be used. Two models stand out as the better ones in validation studies, one best used for smaller nodules and the other for larger ones. To maximise the cost effectiveness of screening with computed tomography, it is essential to select a population at high enough risk. A number of risk models have been developed, of varying complexity. Simpler models may be easier to use in practice but may miss a minority at high risk who have less common but important risk factors. Identification of early symptomatic lung cancer is important to improve early survival and reduce emergency presentations but single symptoms are non-specific. Risk prediction can improve the targeting of investigation and potentially identify patients early. Clinicians need to embrace the concept of estimating the risk of lung cancer in these three important areas because the evidence is strong enough to support a change in the clinical paradigm.

What characteristics of primary care and patients are associated with early death in patients with lung cancer in the UK?

BACKGROUND

The UK has poor lung cancer survival rates and high early mortality, compared to other countries. We aimed to identify factors associated with early death, and features of primary care that might contribute to late diagnosis.

METHODS

All cases of lung cancer diagnosed between 2000 and 2013 were extracted from The Health Improvement Network database. Patients who died within 90 days of diagnosis were compared with those who survived longer. Standardised chest X-ray (CXR) and lung cancer rates were calculated for each practice.

RESULTS

Of 20,142 people with lung cancer, those who died early consulted with primary care more frequently prediagnosis. Individual factors associated with early death were male sex (OR 1.17; 95% CI 1.10 to 1.24), current smoking (OR 1.43; 95% CI 1.28 to 1.61), increasing age (OR 1.80; 95% CI 1.62 to 1.99 for age ≥80 years compared to 65-69 years), social deprivation (OR 1.16; 95% CI 1.04 to 1.30 for Townsend quintile 5 vs 1) and rural versus urban residence (OR 1.22; 95% CI 1.06 to 1.41). CXR rates varied widely, and the odds of early death were highest in the practices which requested more CXRs. Lung cancer incidence at practice level did not affect early deaths.

CONCLUSIONS

Patients who die early from lung cancer are interacting with primary care prediagnosis, suggesting potentially missed opportunities to identify them earlier. A general increase in CXR requests may not improve survival; rather, a more timely and appropriate targeting of this investigation using risk assessment tools needs further assessment.

PET-CT for assessing mediastinal lymph node involvement in patients with suspected resectable non-small cell lung cancer

BACKGROUND

A major determinant of treatment offered to patients with non-small cell lung cancer (NSCLC) is their intrathoracic (mediastinal) nodal status. If the disease has not spread to the ipsilateral mediastinal nodes, subcarinal (N2) nodes, or both, and the patient is otherwise considered fit for surgery, resection is often the treatment of choice. Planning the optimal treatment is therefore critically dependent on accurate staging of the disease. PET-CT (positron emission tomography-computed tomography) is a non-invasive staging method of the mediastinum, which is increasingly available and used by lung cancer multidisciplinary teams. Although the non-invasive nature of PET-CT constitutes one of its major advantages, PET-CT may be suboptimal in detecting malignancy in normal-sized lymph nodes and in ruling out malignancy in patients with coexisting inflammatory or infectious diseases.

OBJECTIVES

To determine the diagnostic accuracy of integrated PET-CT for mediastinal staging of patients with suspected or confirmed NSCLC that is potentially suitable for treatment with curative intent.

SEARCH METHODS

We searched the following databases up to 30 April 2013: The Cochrane Library, MEDLINE via OvidSP (from 1946), Embase via OvidSP (from 1974), PreMEDLINE via OvidSP, OpenGrey, ProQuest Dissertations & Theses, and the trials register www.clinicaltrials.gov. There were no language or publication status restrictions on the search. We also contacted researchers in the field, checked reference lists, and conducted citation searches (with an end-date of 9 July 2013) of relevant studies.

SELECTION CRITERIA

Prospective or retrospective cross-sectional studies that assessed the diagnostic accuracy of integrated PET-CT for diagnosing N2 disease in patients with suspected resectable NSCLC. The studies must have used pathology as the reference standard and reported participants as the unit of analysis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data pertaining to the study characteristics and the number of true and false positives and true and false negatives for the index test, and they independently assessed the quality of the included studies using QUADAS-2. We calculated sensitivity and specificity with 95% confidence intervals (CI) for each study and performed two main analyses based on the criteria for test positivity employed: Activity > background or SUVmax ≥ 2.5 (SUVmax = maximum standardised uptake value), where we fitted a summary receiver operating characteristic (ROC) curve using a hierarchical summary ROC (HSROC) model for each subset of studies. We identified the average operating point on the SROC curve and computed the average sensitivities and specificities. We checked for heterogeneity and examined the robustness of the meta-analyses through sensitivity analyses.

MAIN RESULTS

We included 45 studies, and based on the criteria for PET-CT positivity, we categorised the included studies into three groups: Activity > background (18 studies, N = 2823, prevalence of N2 and N3 nodes = 679/2328), SUVmax ≥ 2.5 (12 studies, N = 1656, prevalence of N2 and N3 nodes = 465/1656), and Other/mixed (15 studies, N = 1616, prevalence of N2 to N3 nodes = 400/1616). None of the studies reported (any) adverse events. Under-reporting generally hampered the quality assessment of the studies, and in 30/45 studies, the applicability of the study populations was of high or unclear concern.The summary sensitivity and specificity estimates for the 'Activity > background PET-CT positivity criterion were 77.4% (95% CI 65.3 to 86.1) and 90.1% (95% CI 85.3 to 93.5), respectively, but the accuracy estimates of these studies in ROC space showed a wide prediction region. This indicated high between-study heterogeneity and a relatively large 95% confidence region around the summary value of sensitivity and specificity, denoting a lack of precision. Sensitivity analyses suggested that the overall estimate of sensitivity was especially susceptible to selection bias; reference standard bias; clear definition of test positivity; and to a lesser extent, index test bias and commercial funding bias, with lower combined estimates of sensitivity observed for all the low 'Risk of bias' studies compared with the full analysis.The summary sensitivity and specificity estimates for the SUVmax ≥ 2.5 PET-CT positivity criterion were 81.3% (95% CI 70.2 to 88.9) and 79.4% (95% CI 70 to 86.5), respectively.In this group, the accuracy estimates of these studies in ROC space also showed a very wide prediction region. This indicated very high between-study heterogeneity, and there was a relatively large 95% confidence region around the summary value of sensitivity and specificity, denoting a clear lack of precision. Sensitivity analyses suggested that both overall accuracy estimates were marginally sensitive to flow and timing bias and commercial funding bias, which both lead to slightly lower estimates of sensitivity and specificity.Heterogeneity analyses showed that the accuracy estimates were significantly influenced by country of study origin, percentage of participants with adenocarcinoma, (¹⁸F)-2-fluoro-deoxy-D-glucose (FDG) dose, type of PET-CT scanner, and study size, but not by study design, consecutive recruitment, attenuation correction, year of publication, or tuberculosis incidence rate per 100,000 population.

AUTHORS' CONCLUSIONS

This review has shown that accuracy of PET-CT is insufficient to allow management based on PET-CT alone. The findings therefore support National Institute for Health and Care (formally 'clinical') Excellence (NICE) guidance on this topic, where PET-CT is used to guide clinicians in the next step: either a biopsy or where negative and nodes are small, directly to surgery. The apparent difference between the two main makes of PET-CT scanner is important and may influence the treatment decision in some circumstances. The differences in PET-CT accuracy estimates between scanner makes, NSCLC subtypes, FDG dose, and country of study origin, along with the general variability of results, suggest that all large centres should actively monitor their accuracy. This is so that they can make reliable decisions based on their own results and identify the populations in which PET-CT is of most use or potentially little value.

Early diagnosis pivotal to survival in lung cancer

The UK has been highlighted, by the International Cancer Benchmarking Project and the EUROCARE groups, as a country with one of the lowest lung cancer survival rates. It has been postulated that this is due to an excess of early deaths, delays in diagnosis are thought to contribute to this problem. A recent study showed that 30% of patients with lung cancer die within the first 90 days and they have seen their GP on average five times in the four months before diagnosis, suggesting there may be opportunities to diagnose these patients earlier in the disease process. The challenge GPs face is to identify and refer those at risk as early as possible and to maintain a high index of suspicion if symptoms persist. The SIGN guideline reiterates the importance of performing a chest X-ray in those in whom the suspicion of lung cancer has been raised and not to be falsely reassured by a normal chest X-ray in a high-risk patient. The initial investigation of choice in secondary care remains a CT scan of the chest and abdomen, followed by PET-CT scanning in those deemed suitable for potentially curative treatment. Smoking cessation reduces the risk of post-operative and systemic treatment-related complications and also reduces the chance of cancer recurrence. Surgery remains the initial treatment of choice for those with early stage disease in NSCLC who are deemed fit enough. Those who have early stage NSCLC (stage I or stage II) who are either medically inoperable or decline surgery should be offered radical radiotherapy. Hospital follow-up should be continued while patients are receiving treatment, complemented by clinical nurse specialist input alongside community support. All patients should have access to specialist palliative care teams. Those with palliative care input have improved quality of life and symptom control and fewer hospitalisations.

Brain metastases following radical surgical treatment of non-small cell lung cancer: is preoperative brain imaging important?

OBJECTIVES

There is a lack of good quality evidence or a clear consensus of opinion internationally regarding who should receive preoperative imaging of the brain prior to radical treatment for non-small cell lung cancer (NSCLC). We aimed to establish the proportion of patients who developed brain metastases following curative surgery and to estimate how many could have been detected by preoperative magnetic resonance imaging (MR).

METHODS

We performed a retrospective analysis of 646 patients who underwent surgery for lung cancer with curative intent at a regional thoracic surgical centre in the United Kingdom. We identified those who developed brain metastases in the postoperative period and, by using volume doubling times, estimated the size of the metastasis at the time of surgery. We then determined the proportion of metastases that would have been seen on preoperative MR brain at detection thresholds of 2 and 5mm diameter.

RESULTS

There was a 6.3% incidence of postoperative brain metastases, with the majority occurring within 12 months of surgery. Those who developed metastases were more likely to have adenocarcinoma and the majority had early stage malignancy (73% stage I or stage II). We estimate that 71% of those who developed cerebral metastases might have been detected had they undergone MR brain as part of their staging (4.4% of all patients).

CONCLUSION

Based on our findings we suggest that, in addition to standard staging investigations, patients have brain imaging (MR or equivalent) prior to curative surgery in NSCLC regardless of preoperative stage.

Appetite stimulants for people with cystic fibrosis

BACKGROUND

Chronic loss of appetite in cystic fibrosis concerns both individuals and families. Appetite stimulants have been used to help cystic fibrosis patients with chronic anorexia attain optimal body mass index and nutritional status. However, these may have adverse effects on clinical status.

OBJECTIVES

The aim of this review is to systematically search for and evaluate evidence on the beneficial effects of appetite stimulants in the management of CF-related anorexia and synthesize reports of any side-effects.

SEARCH METHODS

Trials were identified by searching the Cochrane Cystic Fibrosis and Genetic Disorders Group's Cystic Fibrosis Trials Register, MEDLINE, Embase, CINAHL, handsearching reference lists and contacting local and international experts.Last search of online databases: 01 April 2014.Last search of the Cystic Fibrosis Trials Register: 08 April 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of appetite stimulants, compared to placebo or no treatment for at least one month in adults and children with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Authors independently extracted data and assessed the risk of bias within eligible trials. Meta-analyses were performed.

MAIN RESULTS

Three trials (total of 47 recruited patients) comparing appetite stimulants (cyproheptadine hydrochloride and megesterol acetate) to placebo were included; the numbers of adults or children within each trial were not always reported. The risk of bias of the included trials was graded as moderate.A meta-analysis of all three trials showed appetite stimulants produced a larger increase in weight z score at three months compared to placebo, mean difference 0.61 (95% confidence interval 0.29 to 0.93) (P < 0.001) (n = 40) with no evidence of a difference in effect between two different appetite stimulants. One of these trials also reported a significant weight increase with megesterol acetate compared to placebo at six months (n = 17). The three trials reported no significant differences in forced expiratory volume at one second (per cent predicted) between the appetite stimulant groups and placebo at follow up, with durations ranging from two to nine months. A meta-analysis of two trials showed a significantly higher proportion of patients reporting increased appetite, odds ratio 45.25 (95% confidence interval 3.57 to 573.33) (P = 0.003) (n = 23), but the frequency of reported side effects was undetermined.

AUTHORS' CONCLUSIONS

In the short term (six months) in adults and children, appetite stimulants improved only two of the outcomes in this review - weight (or weight z score) and appetite; and side effects were insufficiently reported to determine the full extent of their impact. Whilst the data may suggest the potential use of appetite stimulants in treating anorexia in adults and children with cystic fibrosis, this is based upon moderate quality data from a small number of trials and so this therapy cannot be conclusively recommended based upon the findings in the review. Clinicians need to be aware of the potential adverse effects of appetite stimulants and actively monitor any patients prescribed these medications accordingly.Research is needed to determine meaningful surrogate measures for appetite and define what constitutes quality weight gain. Future trials of appetite stimulants should use a validated measure of symptoms including a disease-specific instrument for measuring poor appetite. This review highlights the need for multicentred, adequately powered and well-designed trials to evaluate agents to safely increase appetite in people with cystic fibrosis and to establish the optimal mode of treatment.

Small-cell lung cancer in England: trends in survival and chemotherapy using the National Lung Cancer Audit

Background

The purpose of this study was to identify trends in survival and chemotherapy use for individuals with small-cell lung cancer (SCLC) in England using the National Lung Cancer Audit (NLCA).

Methods

We used data from the NLCA database to identify people with histologically proven SCLC from 2004–2011. We calculated the median survival by stage and assessed whether patient characteristics changed over time. We also assessed whether the proportion of patients with records of chemotherapy and/or radiotherapy changed over time.

Results

18,513 patients were diagnosed with SCLC in our cohort. The median survival was 6 months for all patients, 1 year for those with limited stage and 4 months for extensive stage. 69% received chemotherapy and this proportion changed very slightly over time (test for trends p = 0.055). Age and performance status of patients remained stable over the study period, but the proportion of patients staged increased (p-value<0.001), mainly because of improved data completeness. There has been an increase in the proportion of patients that had a record of receiving both chemotherapy and radiotherapy each year (from 19% to 40% in limited and from 9% to 21% in extensive stage from 2004 to 2011). Patients who received chemotherapy with radiotherapy had better survival compared with any other treatment (HR 0.24, 95% CI 0.23–0.25).

Conclusion

Since 2004, when the NLCA was established, the proportion of patients with SCLC having chemotherapy has remained static. We have found an upward trend in the proportion of patients receiving both chemotherapy and radiotherapy which corresponded to a better survival in this group, but as it only applied for a small proportion of patients, it was not enough to change the overall survival.

CT screening for lung cancer: countdown to implementation

Implementation of lung cancer CT screening is currently the subject of a major policy decision within the USA. Findings of the US National Lung Screening Trial showed a 20% reduction in lung cancer mortality and a 6·7% decrease in all-cause mortality; subsequently, five US professional and clinical organisations and the US Preventive Services Task Force recommended that screening should be implemented. Should national health services in Europe follow suit? The European community awaits mortality and cost-effectiveness data from the NELSON trial in 2015-16 and pooled findings of European trials. In the intervening years, a recommendation is proposed that a demonstration trial is done in the UK. In this Review, we summarise the existing evidence and identify questions that remain to be answered before the implementation of international lung cancer screening programmes.

The UK Lung Screen (UKLS): demographic profile of first 88,897 approaches provides recommendations for population screening

The UK Lung Cancer Screening trial (UKLS) aims to evaluate low-dose computed tomography (LDCT) lung cancer population screening in the United Kingdom. In UKLS, a large population sample ages 50 to 75 years is approached with a questionnaire to determine lung cancer risk. Those with an estimated risk of at least 5% of developing lung cancer in the next 5 years (using the Liverpool Lung project risk model) are invited to participate in the trial. Here, we present demographic, risk, and response rate data from the first 88,897 individuals approached. Of note, 23,794 individuals (26.8% of all approached) responded positively to the initial questionnaire; 12% of these were high risk. Higher socioeconomic status correlated positively with response, but inversely with risk (P < 0.001). The 50- to 55-year age group was least likely to participate, and at lowest cancer risk. Only 5% of clinic attendees were ages ≤60 years (compared with 47% of all 88,897 approached); this has implications for cost effectiveness. Among positive responders, there were more ex-smokers than expected from population figures (40% vs. 33%), and fewer current smokers (14% vs. 17.5%). Of note, 32.7% of current smokers and 18.4% of ex-smokers were designated as high risk. Overall, 1,452 of 23,794 positive responders (6.1%) were deemed high risk and attended a recruitment clinic. UKLS is the first LDCT population screening trial, selecting high-risk subjects using a validated individual risk prediction model.

KEY FINDINGS

(i) better recruitment from ex- rather than current smokers, (ii) few clinic attendees ages early 50s, and (iii) representative number of socioeconomically deprived people recruited, despite lower response rates.

Survival of patients with small cell lung cancer undergoing lung resection in England, 1998-2009

Introduction

Chemotherapy or chemoradiotherapy is the recommended treatment for small cell lung cancer (SCLC), except in stage I disease where clinical guidelines state there may be a role for surgery based on favourable outcomes in case series. Evidence supporting adjuvant chemotherapy in resected SCLC is limited but this is widely offered.

Methods

Data on 359 873 patients who were diagnosed with a first primary lung cancer in England between 1998 and 2009 were grouped according to histology (SCLC or non-SCLC (NSCLC)) and whether they underwent a surgical resection. We explored their survival using Kaplan–Meier analysis and Cox regression, adjusting for age, sex, comorbidity and socioeconomic status.

Results

The survival of 465 patients with resected SCLC was lower than patients with resected NSCLC (5-year survival 31% and 45%, respectively), but much higher than patients of either group who were not resected (3%). The difference between resected SCLC and NSCLC diminished with time after surgery. Survival was superior for the subgroup of 198 ‘elective’ SCLC cases where the diagnosis was most likely known before resection than for the subgroup of 267 ‘incidental’ cases where the SCLC diagnosis was likely to have been made after resection.

Conclusions

These data serve as a natural experiment testing the survival after surgical management of SCLC according to NSCLC principles. Patients with SCLC treated surgically for early stage disease may have survival outcomes that approach those of NSCLC, supporting the emerging clinical practice of offering surgical resection to selected patients with SCLC.

Lung cancer survival in England: trends in non-small-cell lung cancer survival over the duration of the National Lung Cancer Audit

Background:

In comparison with other European and North American countries, England has poor survival figures for lung cancer. Our aim was to evaluate the changes in survival since the introduction of the National Lung Cancer Audit (NLCA).

Methods:

We used data from the NLCA to identify people with non-small-cell lung cancer (NSCLC) and stratified people according to their performance status (PS) and clinical stage. Using Cox regression, we calculated hazard ratios (HRs) for death according to the year of diagnosis from 2004/2005 to 2010; adjusted for patient features including age, sex and co-morbidity. We also assessed whether any changes in survival were explained by the changes in surgical resection rates or histological subtype.

Results:

In this cohort of 120 745 patients, the overall median survival did not change; but there was a 1% annual improvement in survival over the study period (adjusted HR 0.99, 95% confidence interval (CI) 0.98–0.99). Survival improvement was only seen in patients with good PS and early stage (adjusted HR 0.97, 95% CI 0.95–0.99) and this was partly accounted for by changes in resection rates.

Conclusion:

Survival has only improved for a limited group of people with NSCLC and increasing surgical resection rates appeared to explain some of this improvement.

The association between smoking quantity and lung cancer in men and women

BACKGROUND

Studies have shown that for the same quantity of cigarettes smoked, women are more likely to develop heart disease than men, but studies in lung cancer have produced conflicting results. We studied the association between smoking quantity and lung cancer in men and women.

METHODS

Using data from The Health Improvement Network (a UK medical research database), we generated a data set comprising 12,121 incident cases of lung cancer and 48,216 age-, sex-, and general practice-matched control subjects. We used conditional logistic regression to calculate ORs for lung cancer according to highest-ever-quantity smoked in men and women separately.

RESULTS

The odds of lung cancer in women who had ever smoked heavily compared with those who had never smoked were increased 19-fold (OR, 19.10; 95% CI, 16.98-21.49), which was more than for men smoking the same quantity (OR, 12.81; 95% CI, 11.52-14.24). There was strong evidence of a difference in effect of quantity smoked on lung cancer between men and women (interaction P < .0001), which remained after adjusting for height (a proxy marker for lung volume).

CONCLUSIONS

Moderate and heavy smoking carry a higher risk of lung cancer in women than in men, and this difference does not seem to be explained by lung volume. The findings suggest that extrapolating risk estimates for lung cancer in men to women will underestimate the adverse impact of smoking in women.

Using socio-demographic and early clinical features in general practice to identify people with lung cancer earlier

INTRODUCTION

In the UK, most people with lung cancer are diagnosed at a late stage when curative treatment is not possible. To aid earlier detection, the socio-demographic and early clinical features predictive of lung cancer need to be identified.

METHODS

We studied 12,074 cases of lung cancer and 120,731 controls in a large general practice database. Logistic regression analyses were used to identify the socio-demographic and clinical features associated with cancer up to 2 years before diagnosis. A risk prediction model was developed using variables that were independently associated with lung cancer up to 4 months before diagnosis. The model performance was assessed in an independent dataset of 1,826,293 patients from the same database. Discrimination was assessed by means of a receiver operating characteristic (ROC) curve.

RESULTS

Clinical and socio-demographic features that were independently associated with lung cancer were patients' age, sex, socioeconomic status and smoking history. From 4 to 12 months before diagnosis, the frequency of consultations and symptom records of cough, haemoptysis, dyspnoea, weight loss, lower respiratory tract infections, non-specific chest infections, chest pain, hoarseness, upper respiratory tract infections and chronic obstructive pulmonary disease were also independently predictive of lung cancer. On validation, the model performed well with an area under the ROC curve of 0.88.

CONCLUSIONS

This new model performed substantially better than the current National Institute for Health and Clinical Excellence referral guidelines and all comparable models. It has the potential to predict lung cancer cases sufficiently early to make detection at a curable stage more likely by allowing general practitioners to better risk stratify their patients. A clinical trial is needed to quantify the absolute benefits to patients and the cost effectiveness of this model in practice.