BACKGROUNDAmong patients with non-small-cell lung cancer (NSCLC), data on intratumor heterogeneity and cancer genome evolution have been limited to small retrospective cohorts. We wanted to prospectively investigate intratumor heterogeneity in relation to clinical outcome and to determine the clonal nature of driver events and evolutionary processes in early-stage NSCLC.METHODSIn this prospective cohort study, we performed multiregion whole-exome sequencing on 100 early-stage NSCLC tumors that had been resected before systemic therapy. We sequenced and analyzed 327 tumor regions to define evolutionary histories, obtain a census of clonal and subclonal events, and assess the relationship between intratumor heterogeneity and recurrence-free survival.RESULTSWe observed widespread intratumor heterogeneity for both somatic copy-number alterations and mutations. Driver mutations in EGFR, MET, BRAF, and TP53 were almost always clonal. However, heterogeneous driver alterations that occurred later in evolution were found in more than 75% of the tumors and were common in PIK3CA and NF1 and in genes that are involved in chromatin modification and DNA damage response and repair. Genome doubling and ongoing dynamic chromosomal instability were associated with intratumor heterogeneity and resulted in parallel evolution of driver somatic copy-number alterations, including amplifications in CDK4, FOXA1, and BCL11A. Elevated copy-number heterogeneity was associated with an increased risk of recurrence or death (hazard ratio, 4.9; P=4.4x10(-4)), which remained significant in multivariate analysis.CONCLUSIONSIntratumor heterogeneity mediated through chromosome instability was associated with an increased risk of recurrence or death, a finding that supports the potential value of chromosome instability as a prognostic predictor. (Funded by Cancer Research UK and others; TRACERx ClinicalTrials.gov number, NCT01888601.)

The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies.

The importance of intratumour genetic and functional heterogeneity is increasingly recognised as a driver of cancer progression and survival outcome. Understanding how tumour clonal heterogeneity impacts upon therapeutic outcome, however, is still an area of unmet clinical and scientific need. TRACERx (TRAcking non-small cell lung Cancer Evolution through therapy [Rx]), a prospective study of patients with primary non-small cell lung cancer (NSCLC), aims to define the evolutionary trajectories of lung cancer in both space and time through multiregion and longitudinal tumour sampling and genetic analysis. By following cancers from diagnosis to relapse, tracking the evolutionary trajectories of tumours in relation to therapeutic interventions, and determining the impact of clonal heterogeneity on clinical outcomes, TRACERx may help to identify novel therapeutic targets for NSCLC and may also serve as a model applicable to other cancer types.

Patients with interstitial lung disease often present with breathlessness, chronic cough, inspiratory crackles on auscultation, and abnormal spirometry.1 2 Over 200 different types of disease can cause thickening of the pulmonary interstitium, with the common final pathway for many of these being fibrosis (figs 1 and 2)⇓ ⇓.3 4 Some forms of interstitial lung disease can be life threatening, such as idiopathic pulmonary fibrosis, approximately 4000 new cases of which are diagnosed in England and Wales each year. Survival rates of 57% at three years and 43% at five years are worse outcomes than those for some cancers.5 About 3000 new cases of sarcoidosis are diagnosed each year in the UK.5 6 Early recognition and treatment of interstitial lung diseases may prevent progression to irreversible pulmonary fibrosis and respiratory failure. This review provides a guide to the initial investigation of patients with suspected interstitial lung disease and provides a summary of further investigations. Fig 1 The pulmonary interstitium is the microscopic space between the alveolar epithelium and capillary endothelium and is crucial for gas exchange Fig 2 Arrows indicate pulmonary interstitium in (left) healthy lung and (right) pulmonary fibrosis. The grossly thickened interstitium in pulmonary fibrosis impairs gas exchange. We sought papers that were fully published between 1966 and April 2010 using appropriate index terms (interstitial lung disease, diffuse parenchymal lung disease) the National Library of Medicine’s computerised search service (providing access to Medline, PreMedline and other related databases). We also consulted Cochrane database systematic reviews and a personal archive of references. Some forms of interstitial lung disease are idiopathic, whereas others are associated with connective tissue diseases, commonly prescribed drugs, smoking, and exposures to environmental factors such as dusts.7 The histopathological classification of interstitial lung diseases is complex, simplified in figure 3 …

Atypical adenomatous hyperplasia (AAH) is a recognised precursor for peripheral parenchymal-type adenocarcinoma whereby AAH transforms into localised non-mucinous bronchioloalveolar carcinoma, wherein alveolar collapse, stromal fibrosis and invasion develop. In our patient population, AAH has been found in around 12% of lung cancer resections and in 23% of resections for adenocarcinoma. About half reported AAH lesions are solitary, some cases yield between 2-5 lesions but up to 20% show over 5 lesions. Little is known about the likelihood or rate of transformation of AAH into adenocarcinoma. The few follow-up studies published have involved relatively short follow-up and none have shown any relationship between AAH and survival. We present the first case-control study investigating the survival of patients with AAH in lung resection specimens. 116 patients with AAH in their resection specimen were compared with 232 controls without AAH. Cases and controls were matched for tumour histology, T & N stage, age and year of surgery. All cases were treated in the Aberdeen Cardio-Thoracic Surgery Unit, the tertiary specialist referral centre for the north of Scotland. All cases of AAH were detected during routine gross and histological examination of lungs resected for primary carcinoma. All lesions identified on gross examination of 1cm thick parasagittal slices of formalin-inflated lung resections were sampled and/or up to 6 random parenchymal tissue blocks were taken. Survival data were derived from our lung cancer resection database, Cancer Registry and Hospital patient data sources. Tumour stage, nodal status and histology (WHO 2004) were 100% matched between cases and controls. Median ages were 65.4 (IQR 57.5 - 71.0) and 64.5 (58.3 - 70.2) years respectively for cases and controls. More AAH patients were female (50.9% vs 35.3%, p=0.005). Of those cases with AAH, 15% had more than 5 lesions recorded. As expected, most (69%) of the cases had adenocarcinomas. Median follow-up was 32 months for cases and 30 months for controls (95th centiles 130 and 147 months respectively). No difference was found in the survival of cases with AAH and controls (Median survival [95% confidence interval], 35 [12.3 - 57.7] months vs 39 [29.0 - 49.0] months respectively, p=0.81). When cases were categorised to identify patients with more than 5 AAH lesions (n=17), median survivals for cases with 1-5 AAH lesions was 36 [11.9 - 60] months while for those with over 5 AAHs it was 22 [0 - 57] months, however this difference was not statistically significant (p=0.56). In multi-variate analysis, T and N status (p≤0.001), large cell undifferentiated and sarcomatoid histology (p=0.045 and 0.050) and female gender (p=0.029) were significantly associated with survival but there was no evidence of interactions between the presence of AAH and any of these factors. In this case-control study the presence of AAH in lungs resected for primary carcinoma does not influence patient survival. More data are required on patients with large numbers of AAH to better understand the significance in this group and determine clinical follow-up strategy in AAH patients.

We report a rare case of spontaneous dissection of an anomalous systemic artery supplying a normal basal segment of the right lung during pregnancy, leading to recurrent hemoptysis. This article aims to discuss the clinical presentation, diagnostic curiosity, management using a minimally invasive technique (video-assisted thoracoscopic lobectomy), and finally the histopathologic findings.