Nanda Horeweg

Characteristics of Lung Cancers Detected by Computer Tomography Screening in the Randomized NELSON Trial

RATIONALE The NELSON (Nederlands Leuvens Longkanker Screenings Onderzoek) trial is, with 15,822 participants, the largest European lung cancer computer tomography screening trial. A volumetry-based screening strategy, stringent criteria for a positive screening, and an increasing length of screening interval are particular features of the NELSON trial. OBJECTIVES To determine the effect of stringent referral criteria and increasing screening interval on the characteristics of screen-detected lung cancers, and to compare this across screening rounds, between sexes, and with other screening trials. METHODS All NELSON participants with screen-detected lung cancer in the first three rounds were included. Lung cancer stage at diagnosis, histological subtype, and tumor localization were compared between the screening rounds, the sexes, and with other screening trials. MEASUREMENTS AND MAIN RESULTS In the first three screening rounds, 200 participants were diagnosed with 209 lung cancers. Of these lung cancers, 70.8% were diagnosed at stage I and 8.1% at stage IIIB-IV, and 51.2% were adenocarcinomas. There was no significant difference in cancer stage, histology, or tumor localization across the screening rounds. Women were diagnosed at a significantly more favorable cancer stage than men. Compared with other trials, the screen-detected lung cancers of the NELSON trial were relatively more often diagnosed at stage I and less often at stage IIIB-IV. CONCLUSIONS Despite stringent criteria for a positive screening, an increasing length of screening interval, and few female participants, the screening strategy of the NELSON trial resulted in a favorable cancer stage distribution at diagnosis, which is essential for the effectiveness of our screening strategy. Clinical trial registered with www.trialregister.nl (ISRCTN63545820).

The role of conventional bronchoscopy in the workup of suspicious CT scan screen-detected pulmonary nodules.

BACKGROUND Up to 50% of the participants in CT scan lung cancer screening trials have at least one pulmonary nodule. To date, the role of conventional bronchoscopy in the workup of suspicious screen-detected pulmonary nodules is unknown. If a bronchoscopic evaluation could be eliminated, the cost-effectiveness of a screening program could be enhanced and the potential harms of bronchoscopy avoided. METHODS All consecutive participants with a positive result on a CT scan lung cancer screening between April 2004 and December 2008 were enrolled. The diagnostic sensitivity and negative predictive value were calculated at the level of the suspicious nodules. In 95% of the nodules, the gold standard for the outcome of the bronchoscopy was based on surgical resection specimens. RESULTS A total of 318 suspicious lesions were evaluated by bronchoscopy in 308 participants. The mean ± SD diameter of the nodules was 14.6 ± 8.7 mm, whereas only 2.8% of nodules were > 30 mm in diameter. The sensitivity of bronchoscopy was 13.5% (95% CI, 9.0%-19.6%); the specificity, 100%; the positive predictive value, 100%; and the negative predictive value, 47.6% (95% CI, 41.8%-53.5%). Of all cancers detected, 1% were detected by bronchoscopy only and were retrospectively invisible on both low-dose CT scan and CT scan with IV contrast. CONCLUSION Conventional white-light bronchoscopy should not be routinely recommended for patients with positive test results in a lung cancer screening program.

Towards a close computed tomography monitoring approach for screen detected subsolid pulmonary nodules

Pulmonary subsolid nodules (SSNs) have a high likelihood of malignancy, but are often indolent. A conservative treatment approach may therefore be suitable. The aim of the current study was to evaluate whether close follow-up of SSNs with computed tomography may be a safe approach. The study population consisted of participants of the Dutch-Belgian lung cancer screening trial (Nederlands Leuvens Longkanker Screenings Onderzoek; NELSON). All SSNs detected during the trial were included in this analysis. Retrospectively, all persistent SSNs and SSNs that were resected after first detection were segmented using dedicated software, and maximum diameter, volume and mass were measured. Mass doubling time (MDT) was calculated. In total 7135 volunteers were included in the current analysis. 264 (3.3%) SSNs in 234 participants were detected during the trial. 147 (63%) of these SSNs in 126 participants disappeared at follow-up, leaving 117 persistent or directly resected SSNs in 108 (1.5%) participants available for analysis. The median follow-up time was 95 months (range 20–110 months). 33 (28%) SSNs were resected and 28 of those were (pre-) invasive. None of the non-resected SSNs progressed into a clinically relevant malignancy. Persistent SSNs rarely developed into clinically manifest malignancies unexpectedly. Close follow-up with computed tomography may be a safe option to monitor changes. Persistent subsolid pulmonary nodules may be safely monitored with follow-up computed tomography http://ow.ly/CqWN1

Complications following lung surgery in the Dutch-Belgian randomized lung cancer screening trial

OBJECTIVES To assess the complication rate in participants of the screen arm of the NELSON lung cancer screening trial who underwent surgical resection and to investigate, based on a literature review, whether the complication rate, length of hospital stay, re-thoracotomy and mortality rates after a surgical procedure were different from those of the non-screening series, taking co-morbidity into account. METHODS Between April 2004 and December 2008, 198 subjects underwent thoracic surgery. Co-morbid conditions were retrieved from the medical records. Postoperative complications were classified as minor and major. RESULTS In total, 182 thoracotomies, 5 thoracotomies after video-assisted thoracoscopic surgery (VATS) and 11 VATS procedures were performed. In these patients, 36% had chronic obstructive lung disease, 16% coronary artery disease, 14% diabetes mellitus and 11% peripheral vascular disease. Following thoracotomy, 47% (88/187) had ≥1 minor (7-57% in literature) and 10% (18/187) ≥1 major complication (2-26% in literature); following VATS, 38% (6/16) had ≥1 minor complication, but no major complications. Seventeen per cent (3/18) of major complications and 21% (20/96) of minor complications were seen in subjects operated for benign disease. The re-thoracotomy rate was 3% and there was no 30-day mortality after thoracotomy or VATS (0-8.3% in literature). The mortality rate of 0% after surgical procedures is low when compared with the non-screening series (0-8.3%); the rate of complications (53%) is within range when compared with the non-screening series (8.5-58%). CONCLUSIONS In conclusion, mortality rates after surgical procedures are lower in the NELSON lung cancer screening trial than those in the non-screening series. The rate of complications is within the same range as in the non-screening series. TRIAL REGISTRATION NUMBER ISR CTN 63545820.

Blinded and uniform cause of death verification in a lung cancer CT screening trial

Disease-specific mortality is the final outcome of a lung cancer screening trial, therefore cause of death verification is crucial. The use of death certificates for this purpose is debated because of bias, inaccurate completion and incorrect ante mortem diagnoses. A cause of death evaluation process was designed to ensure a uniform and unbiased determination of the graduation of certainty that lung cancer was the underlying cause of death. An independent clinical expert committee will review the medical files of all deceased participants once diagnosed with lung cancer and will make use of a flow chart and predetermined criteria. A pilot study of fifty cases was conducted to determine the performance of this process and to compare the outcome with the official death certificates. The independent review has shown an agreement of 90% (kappa 0.65), which demonstrates a uniform classification. The sensitivity and specificity of the death certificates for lung cancer specific mortality were 95.2 and 62.5%. This demonstrates a limited distinctive character of the death certification process in lung cancer patients. Our results imply that the final outcome of a lung cancer screening trial cannot reliably be established without predetermined criteria and an independent review of blinded cases.

An Official American Thoracic Society Research Statement: A Research Framework for Pulmonary Nodule Evaluation and Management

BACKGROUND Pulmonary nodules are frequently detected during diagnostic chest imaging and as a result of lung cancer screening. Current guidelines for their evaluation are largely based on low-quality evidence, and patients and clinicians could benefit from more research in this area. METHODS In this research statement from the American Thoracic Society, a multidisciplinary group of clinicians, researchers, and patient advocates reviewed available evidence for pulmonary nodule evaluation, characterized six focus areas to direct future research efforts, and identified fundamental gaps in knowledge and strategies to address them. We did not use formal mechanisms to prioritize one research area over another or to achieve consensus. RESULTS There was widespread agreement that novel tests (including novel imaging tests and biopsy techniques, biomarkers, and prognostic models) may improve diagnostic accuracy for identifying cancerous nodules. Before they are used in clinical practice, however, better evidence is needed to show that they improve more distal outcomes of importance to patients. In addition, the pace of research and the quality of clinical care would be improved by the development of registries that link demographic and nodule characteristics with patient-level outcomes. Methods to share data from registries are also necessary. CONCLUSIONS This statement may help researchers to develop impactful and innovative research projects and enable funders to better judge research proposals. We hope that it will accelerate the pace and increase the efficiency of discovery to improve the quality of care for patients with pulmonary nodules.

Low-dose computed tomography screening for lung cancer: Results of the first screening round

Evaluation of: National Lung Screening Trial Research Team, Church TR, Black WC, Aberle DR et al. Results of initial low-dose computed tomographic screening for lung cancer. N. Engl. J. Med. 368, 1980-1991 (2013). In 2011, the US NLST trial demonstrated that mortality from lung cancer can be reduced by using low-dose computed tomography (LDCT) screening rather than chest x-ray (CXR) screening. This paper from the US NLST research team focuses on the results of the initial round of LDCT for lung cancer. A total of 53,439 participants were included and randomly assigned to LDCT screening (n = 26,715) or CXR screening (n = 26,724). In total, 27.3% of the participants in the LDCT group and 9.2% in the CXR group had a positive screening result. As a result, 3.8% (LDCT group) and 5.7% (CXR group) of these subjects were diagnosed with lung cancer. The sensitivity (93.8%) and specificity (73.4%) for lung cancer were higher for LDCT compared with CXR screening; 73.5 and 91.3%, respectively.

Baseline Characteristics and Mortality Outcomes of Control Group Participants and Eligible Non-Responders in the NELSON Lung Cancer Screening Study.

Introduction: Individuals who are younger, have a high socioeconomic background and/or have a healthy lifestyle are more inclined to participate in screening trials. This form of bias may affect the generalizability of study results to the target population. This study aimed to investigate the generalizability of the NELSON lung cancer screening trial to the Dutch population. Methods: People at high risk for developing lung cancer were identified by sending a health questionnaire to 606,409 persons aged 50–74 years, based on population registries. Eligible subjects received an invitation to participate (n = 30,051). 15,822 subjects agreed to participate and were randomized, whereas 15,137 did not respond (so-called eligible nonresponders). Baseline characteristics and mortality profiles were compared between control group participants and eligible nonresponders. Results: Participants had better self-reported health (p = 0.02), were younger, more physically active, higher educated, and more often former smokers compared with eligible nonresponders (all p < 0.001). No differences were seen in self-reported outcomes of pulmonary tests, history of lung cancer, and smoked pack-years. Mortality due to all-causes (p < 0.001) and mortality classification separately was lower among participants. However, the proportion of subjects death due to cancer was higher among participants (62.4% vs. 54.9%). Conclusion: Modest differences in baseline characteristics between participants and eligible nonresponders, led to minor differences in mortality profiles. However, group sizes were large and therefore it seems unlikely that these small differences will influence the generalizability of the NELSON trial. Results of the NELSON trial can roughly be used to predict the effect of population-based lung cancer screening.

Agreement of diameter- and volume-based pulmonary nodule management in CT lung cancer screening

Methods Baseline data of 2,240 solid intermediate-sized nodules (volume 50-500mm) in 1,498 Dutch-Belgian NELSON trial participants were used. Extrapolated volume based on semi-automatic (SA) maximum diameter and mean of maximum transversal and perpendicular diameter were compared to SA volume measurements by Bland-Altman plots. Analyses were repeated by margin (smooth, lobulated, spiculated, and irregular) and shape (spherical or non-spherical). In 100 randomly selected nodules, diameters were measured manually by two independent radiologists, and compared to the SA diameters.