Residual ctDNA after treatment predicts early relapse in patients with early-stage non-small cell lung cancer.

BACKGROUND: Identification of residual disease in patients with localized non-small cell lung cancer (NSCLC) following treatment with curative intent holds promise to identify patients at risk of relapse. New methods can detect circulating tumour DNA (ctDNA) in plasma to fractional concentrations as low as a few parts per million, and clinical evidence is required to inform their use. PATIENTS AND METHODS: We analyzed 363 serial plasma samples from 88 patients with early-stage NSCLC (48.9%/28.4%/22.7% at stage I/II/III), predominantly adenocarcinomas (62.5%), treated with curative intent by surgery (n = 61), surgery and adjuvant chemotherapy/radiotherapy (n = 8), or chemoradiotherapy (n = 19). Tumour exome sequencing identified somatic mutations and plasma was analyzed using patient-specific RaDaR™ assays with up to 48 amplicons targeting tumour-specific variants unique to each patient. RESULTS: ctDNA was detected before treatment in 24%, 77% and 87% of patients with stage I, II and III disease, respectively, and in 26% of all longitudinal samples. The median tumour fraction detected was 0.042%, with 63% of samples <0.1% and 36% of samples <0.01%. ctDNA detection had clinical specificity >98.5% and preceded clinical detection of recurrence of the primary tumour by a median of 212.5 days. ctDNA was detected after treatment in 18/28 (64.3%) of patients who had clinical recurrence of their primary tumour. Detection within the landmark timepoint 2 weeks to 4 months after treatment end occurred in 17% of patients, and was associated with shorter recurrence-free survival [hazard ratio (HR): 14.8, P <0.00001] and overall survival (HR: 5.48, P <0.0003). ctDNA was detected 1-3 days after surgery in 25% of patients yet was not associated with disease recurrence. Detection before treatment was associated with shorter overall survival and recurrence-free survival (HR: 2.97 and 3.14, P values 0.01 and 0.003, respectively). CONCLUSIONS: ctDNA detection after initial treatment of patients with early-stage NSCLC using sensitive patient-specific assays has potential to identify patients who may benefit from further therapeutic intervention.

Adenocarcinoma spectrum lesions of the lung: Detection, pathology and treatment strategies.

Adenocarcinoma has become the most prevalent lung cancer sub-type and its frequency is increasing. The earliest stages in the development of lung adenocarcinomas are visible using modern computed tomography (CT) as ground glass nodules. These pre-invasive nodules can progress over time to become invasive lung adenocarcinomas. Lesions in this developmental pathway are termed 'adenocarcinoma spectrum' lesions. With the introduction of lung cancer screening programs there has been an increase in the detection of these lesions raising questions about natural history, surveillance and treatment. Here we review how the radiological appearance of an adenocarcinoma spectrum lesion relates to its underlying pathology and explore the natural history and factors driving lesion progression. We examine the molecular changes that occur at each stage of adenocarcinoma spectrum lesion development, including the effects of the driver mutations, EGFR and KRAS, that are key to invasive adenocarcinoma pathology. A better understanding of the development of pre-invasive disease will create treatment targets. Our understanding of how tumours interact with the immune system has led to the development of new therapeutic strategies. We review the role of the immune system in the development of adenocarcinoma spectrum lesions. With a clear preinvasive phase there is an opportunity to treat early adenocarcinoma spectrum lesions before an invasive lung cancer develops. We review current management including surveillance, surgical resection and oncological therapy as well as exploring potential future treatment avenues.

UK Lung Cancer RCT Pilot Screening Trial: baseline findings from the screening arm provide evidence for the potential implementation of lung cancer screening.

BACKGROUND: Lung cancer screening using low-dose CT (LDCT) was shown to reduce lung cancer mortality by 20% in the National Lung Screening Trial. METHODS: The pilot UK Lung Cancer Screening (UKLS) is a randomised controlled trial of LDCT screening for lung cancer versus usual care. A population-based questionnaire was used to identify high-risk individuals. CT screen-detected nodules were managed by a pre-specified protocol. Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction. RESULTS: 247 354 individuals aged 50-75 years were approached; 30.7% expressed an interest, 8729 (11.5%) were eligible and 4055 were randomised, 2028 into the CT arm (1994 underwent a CT). Forty-two participants (2.1%) had confirmed lung cancer, 34 (1.7%) at baseline and 8 (0.4%) at the 12-month scan. 28/42 (66.7%) had stage I disease, 36/42 (85.7%) had stage I or II disease. 35/42 (83.3%) had surgical resection. 536 subjects had nodules greater than 50 mm(3) or 5 mm diameter and 41/536 were found to have lung cancer. One further cancer was detected by follow-up of nodules between 15 and 50 mm(3) at 12 months. The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening, under the UKLS protocol, was £8466 per quality adjusted life year gained (CI £5542 to £12 569). CONCLUSIONS: The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80% of cases. Health economic analysis suggests that the intervention would be cost effective-this needs to be confirmed using data on observed lung cancer mortality reduction. TRIAL REGISTRATION: ISRCTN 78513845.

The endoplasmic reticulum stress marker CHOP predicts survival in malignant mesothelioma.

BACKGROUND: Mesothelioma is an incurable cancer originating from the mesothelial cells that line the pleural, peritoneal and pericardial cavities. These cells synthesise large quantities of surface glycoproteins, rendering them dependent upon efficient endoplasmic reticulum (ER) function. When faced with elevated levels of secretory protein load, cells are said to experience ER stress, which has been implicated in the pathogenesis of many human diseases including cancer. METHOD: We set out to measure markers of ER stress in malignant mesothelioma and to determine whether ER stress signalling correlates with clinical parameters. RESULTS: We observed that expression of the ER stress-responsive transcription factor C/EBP homologous protein (CHOP) correlated with patient survival and remained an independent prognostic variable in pairwise comparisons with all clinical variables tested. The most parsimonious multivariate model in our study comprised only performance status and CHOP staining. In contrast, expression of the ER stress-responsive phosphatase growth arrest and DNA damage 34 (GADD34) correlated with the degree of mesothelial differentiation, being lost progressively in biphasic and sarcomatoid mesotheliomas. CONCLUSION: Our findings suggest that staining for CHOP provides prognostic information that may be useful in the stratification of patients with mesothelioma. Staining for GADD34 may prove useful in classification of mesothelioma histopathology.

Accuracy of cell typing in nonsmall cell lung cancer by EBUS/EUS-FNA cytological samples.

Endoscopic ultrasound-guided transbronchial or transoesophageal lymph node aspiration is increasingly used as a method of diagnosing nonsmall cell carcinoma. Data validating the accuracy of cell typing of nonsmall cell carcinoma using these cytological samples has not been assessed. 23 samples were identified in Edinburgh, UK and a further 25 in Cambridge, UK, with matching histological samples. The morphological cell type, as assessed on the cytological preparations and cell blocks, was recorded and immunohistochemical staining was performed, where possible, as an adjunct. The final cell type, as assessed by morphology with or without immunohistochemistry, was correlated with that reported in the paired histological samples. Cell blocks with tumour were available in 39 out of 48 cases. The accuracy of cell typing when no cell block was available was four out of nine cases. This increased to 25 out of 39 when a cell block was available, increasing to 33 out of 39 with the addition of immunohistochemistry. The overall accuracy of classification was 37 out of 48 cases. Accurate cell typing of nonsmall cell carcinomas can be performed using endoscopically derived fine-needle aspirates. The importance of obtaining sufficient material for the production of cell blocks is critical in allowing optimal assessment.

Bcl-2 and ß1-integrin predict survival in a tissue microarray of small cell lung cancer.

INTRODUCTION: Survival in small cell lung cancer (SCLC) is limited by the development of chemoresistance. Factors associated with chemoresistance in vitro have been difficult to validate in vivo. Both Bcl-2 and ß(1)-integrin have been identified as in vitro chemoresistance factors in SCLC but their importance in patients remains uncertain. Tissue microarrays (TMAs) are useful to validate biomarkers but no large TMA exists for SCLC. We designed an SCLC TMA to study potential biomarkers of prognosis and then used it to clarify the role of both Bcl-2 and ß(1)-integrin in SCLC. METHODS: A TMA was constructed consisting of 184 cases of SCLC and stained for expression of Bcl-2 and ß(1)-integrin. The slides were scored and the role of the proteins in survival was determined using Cox regression analysis. A meta-analysis of the role of Bcl-2 expression in SCLC prognosis was performed based on published results. RESULTS: Both proteins were expressed at high levels in the SCLC cases. For Bcl-2 (n=140), the hazard ratio for death if the staining was weak in intensity was 0.55 (0.33-0.94, P=0.03) and for ß(1)-integrin (n=151) was 0.60 (0.39-0.92, P=0.02). The meta-analysis showed an overall hazard ratio for low expression of Bcl-2 of 0.91(0.74-1.09). CONCLUSIONS: Both Bcl-2 and ß(1)-integrin are independent prognostic factors in SCLC in this cohort although further validation is required to confirm their importance. A TMA of SCLC cases is feasible but challenging and an important tool for biomarker validation.

Interobserver variation in the classification of thymic tumours--a multicentre study using the WHO classification system.

AIMS: To test the reproducibility of the current World Health Organization (WHO) classification of thymic epithelial tumours and to determine the level of interobserver variation within a group of pathologists, all with experience and expertise in thoracic pathology. METHODS AND RESULTS: Ninety-five thymic tumours were circulated to a group of 17 pathologists in the UK and The Netherlands over a 1-year period. Participants were asked to classify them according to WHO criteria. The diagnoses were subjected to statistical analysis and kappa values calculated. The overall level of agreement was moderate (kappa 0.45). When the categories were reduced in number by creating two groups, (A + AB + B1 + B2 and B3 + C), the level of agreement increased to 0.62. An alternative grouping (A + AB + B1 and B2 + B3 + C) increased it slightly further. The best agreement was in tumour types A and AB. Difficulties arose in distinguishing B1 tumours from B2 tumours and B2 tumours from B3 tumours. CONCLUSIONS: Although the WHO system describes a number of well-defined tumour types with clear diagnostic criteria, the overall level of agreement was moderate and improved if some groups were amalgamated.

Mesothelioma with non-pleural malignancy: a red herring or just an uncommon pairing?

Malignant pleural mesothelioma (MPM) is a highly aggressive cancer of the pleura with a well-established male predominance and causative link with asbestos exposure. We report four cases of female patients with MPM referred for palliation of symptoms thought to be due to previous non-pleural malignancy.With emerging novel treatments for MPM, this article discusses four unusual cases of MPM occurring in the setting of other malignancy, highlights the importance of considering a primary diagnosis of MPM even in patients with other malignancy, and reinforces the benefits of video-assisted surgical biopsy which allows simultaneous diagnosis and treatment.

Desquamative interstitial pneumonia, respiratory bronchiolitis and their relationship to smoking.

AIMS: Respiratory bronchiolitis (RB) and desquamative interstitial pneumonia (DIP) are closely associated histological patterns of interstitial pneumonia, although there are no studies on the extent of individual histological parameters. Furthermore, the term smoking related-interstitial lung disease (SR-ILD) has been proposed as a term to encompass patients with both these histological patterns who give a history of smoking, though it is not well defined how this term relates to historical cases of DIP. The aim of this study was to compare histological parameters in cases of DIP and RB and then to review in detail clinical, imaging and histological data for DIP in relation to a history of smoking. METHODS AND RESULTS: Forty-nine cases were reviewed, 24 with RB and 25 with DIP; five cases of DIP were re-classified as RB on review due to bronchocentricity of the infiltrate. There was a significantly greater extent of interstitial fibrosis (P = 0.02), lymphoid follicles (P < 0.001) and eosinophilic infiltration (P < 0.0001) in patients with DIP compared with RB. In addition, the extents of these three parameters were significantly interrelated. Patients with DIP had a lower incidence of smoking (60%) when compared with patients with RB-ILD (93%) (P < 0.005). Further analysis of smokers versus never-smokers with DIP showed no difference in histological parameters, extent of haemosiderin deposition or the number of CD1a+ macrophages between the two groups, nor were there any differences in clinical data to suggest other aetiologies. Follow-up high-resolution computed tomography data from patients with DIP suggested that a pattern of fibrotic non-specific interstitial pneumonia (NSIP) may develop in the long term in both smokers and never-smokers. CONCLUSION: There are significant differences in the extent of interstitial fibrosis, lymphoid follicles and eosinophilic infiltration between DIP and RB, as well as a much lower incidence of smoking in patients with DIP. Whether the lower reported incidence of smoking in DIP reflects referral bias or conservatism in giving a history of smoking remains uncertain, as neither histological parameters nor clinical data indicate a difference between smokers and never-smokers with DIP. Nevertheless, some cases of DIP are likely to remain idiopathic and unrelated to RB, though still have a good prognosis. Furthermore, they may evolve into a pattern resembling fibrotic NSIP. Therefore, whilst SR-ILD is appropriate in the correct clinical setting, the distinction between the histological patterns of RB and DIP remains appropriate.

Pulmonary malacoplakia in an immunocompetent girl: a case report.

Malacoplakia is an unusual inflammatory condition with distinctive histologic features. Involvement of the lung is quite uncommon and is rarely described in paediatrics. We report on a case of pulmonary malacoplakia in a teenage girl.

Transplant histopathology for the general histopathologist.

The number of patients undergoing solid organ transplants and surviving long-term has increased enormously in the last 10 years. This means that pathologists in non-specialist transplant centres are increasingly involved in the interpretation of biopsy and autopsy material from allograft recipients. This includes evaluation of allograft histology, or specimens from other native tissues, which nonetheless still have to be assessed in the setting of transplantation and immunosuppressive therapy. In this first review article we will provide an overview of the pathology of lung transplantation, and briefly describe heart and pancreatic transplants, as well as aspects of general surgical pathology and the role of the autopsy in these patients.

Squamous cell carcinoma arising in Hailey-Hailey disease of the vulva.

A 61-year-old woman, who was known to have Hailey-Hailey disease, presented with increasing vulval soreness. Biopsy showed vulval intraepithelial neoplasia (VIN) 3 and subsequent histology from a vulvectomy specimen showed extensive VIN with early invasive squamous cell carcinoma. This may be another example of chronic inflammation of the vulval area leading to the development of squamous cell carcinoma. However, in this case, chronic human papillomavirus may also have played a part, leading to VIN and reactivation of the Hailey-Hailey disease. We can find no previous reports of squamous cell carcinoma developing in the setting of Hailey-Hailey disease.

Fatal fungal infection complicating aortic dissection following coronary artery bypass grafting.

The case of a 52-year-old man with severe coronary atheroma/ischaemic heart disease, who underwent successful triple vessel coronary artery bypass grafting is described. One month later this was complicated by aortic dissection arising at the aortic cannulation site. An emergency resection and Dacron graft placement were performed. Five weeks later he represented with haemoptysis. Despite inconclusive investigations the patient went on to suffer a massive fatal haemoptysis. Autopsy revealed Candida infection of the graft with a secondary aortobronchial fistula.

Lack of association between thyroid and adrenal nodules: a histological study.

The prevalence of thyroid nodules is increased in patients with Cushing's disease, but the possibility of an association between thyroid and adrenal nodules in other patient groups has not been formally tested. We have evaluated the co-existence of thyroid and adrenal nodules in retrospective and prospective autopsy studies. Retrospective (83 autopsies) and prospective (29 autopsies) blinded studies of thyroid and adrenal gland histopathology were performed by two experienced histopathologists in unselected autopsies. The presence of nodules, defined as areas of tissue having discrete edges within the gland parenchyma seen as a step difference between the cells or architecture adjacent to the nodule, was determined for each gland. No association was found between the presence of adrenal and thyroid nodules in either the retrospective or prospective studies (p>0.2 for both). In the retrospective study, 23% of specimens had thyroid nodules and 28% adrenal nodules. In the prospective study, 24% of specimens had thyroid nodules and 7% adrenal nodules. The proportion of patients with adrenal nodules in the prospective study was significantly less than that in the retrospective study. In conclusion, thyroid and adrenal nodules are frequent autopsy findings in the general population but we have found no evidence of a relationship between the occurrence of nodules in these glands.