Tracking genomic cancer evolution for precision medicine: the lung TRACERx study.

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.

Asbestos: when the dust settles an imaging review of asbestos-related disease.

Asbestos-related neoplastic and nonneoplastic diseases of the lungs and pleura range from pleural effusion and pleural plaques to lung cancer and malignant mesothelioma. Pleural effusions are typically hemorrhagic exudates of mixed cellularity but do not typically contain asbestos bodies. The classic distribution of pleural plaques seen on chest radiographs is the posterolateral chest wall between the seventh and tenth ribs, lateral chest wall between the sixth and ninth ribs, the dome of the diaphragm, and the mediastinal pleura. Computed tomographic (CT) findings support this distribution but also show anterior and paravertebral plaques not well shown at chest radiography. Imaging features of diffuse pleural thickening include a continuous sheet, often involving the costophrenic angles and apices, that rarely calcifies. The typical CT features of round atelectasis are of a round or oval mass that abuts the pleura, a "comet tail" of bronchovascular structures going into the mass, and thickening of the adjacent pleura. Features of asbestosis on chest radiographs include ground-glass opacification, small nodular opacities, "shaggy" cardiac silhouette, and ill-defined diaphragmatic contours. CT, however, is more sensitive in their detection. Chest radiography in patients with malignant mesothelioma may show an effusion, pleural thickening, and as the tumor progresses, a more lobulated outline. CT can help identify the disease in its early stages. Asbestos-related cancers can occur anywhere in the lungs. Recognition of the clinical, radiologic, and pathologic features of these diseases will be important for some years to come.