Philip Hasleton

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma.

Introduction: Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies. Methods: An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach. Results: The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized. Conclusions: This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.

Epstein-Barr virus replication within pulmonary epithelial cells in cryptogenic fibrosing alveolitis.

BACKGROUND--Cryptogenic fibrosing alveolitis (synonymous with idiopathic pulmonary fibrosis) is a clinically heterogeneous condition in which the precipitating factor is unclear. Both environmental and infective factors have been implicated. An association between Epstein-Barr virus (EBV) and cryptogenic fibrosing alveolitis was suggested over a decade ago by a study based on EBV serology, but the significance of this has been unclear. METHODS--Lung tissue obtained surgically from patients (n = 20) with cryptogenic fibrosing alveolitis was investigated for evidence of EBV replication and compared with lung tissue from 21 control patients. Fourteen of the 20 patients had received no specific therapy for cryptogenic fibrosing alveolitis at the time of biopsy. Monoclonal antibodies directed against the EBV viral antigens, EBV viral capsid antigen (VCA) and gp 340/220 antigen, which are expressed during the lytic phase of the EBV life cycle, were studied. RESULTS--Fourteen (70%) of the 20 patients with cryptogenic fibrosing alveolitis were positive for both EBV VCA and gp 340/220 compared with two (9%) of the 21 controls. In the patients with cryptogenic fibrosing alveolitis viral replication was localised to pulmonary epithelial cells using epithelial cell markers, and immunohistochemical analysis confirmed the staining to be within type II alveolar cells. CONCLUSIONS--This is the first report of in vivo EBV replication within epithelial cells of the lower respiratory tract in an immunocompetent human host. Furthermore, this suggests that EBV may be an immune trigger or contribute to lung injury in cryptogenic fibrosing alveolitis, thus offering a potential new avenue of treatment.

Genotypic variation in the transforming growth factor-β1 gene : Association with transforming growth factor-β1 production, fibrotic lung disease, and graft fibrosis after lung transplantation

BACKGROUND Transforming growth factor (TGF)-beta1 is a profibrogenetic cytokine that has been implicated in the development of fibrosis in transplanted tissues. In this study, we have analyzed the genetic regulation of TGF-beta1 production in lung transplant recipients. METHOD A polymerase chain reaction-single-stranded conformational polymorphism technique was used to detect polymorphisms in the TGF-beta1 gene from genomic DNA. Polymorphisms were shown to correlate with in vitro TGF-beta1 production by stimulated lymphocytes. A single-specific oligonucleotide probe hybridization method was devised to screen for these polymorphisms in lung transplant groups and controls. RESULTS We have identified five polymorphisms in the TGF-beta1 gene: two in the promoter region at positions -800 and -509, one at position +72 in a nontranslated region, and two in the signal sequence at positions +869 and +915. The polymorphism at position +915 in the signal sequence, which changes codon 25 (arginine-->proline), is associated with interindividual variation in levels of TGF-beta1 production. Stimulated lymphocytes of homozygous genotype (arginine/arginine) from control individuals produced significantly more TGF-beta1 in vitro (10037+/-745 pg/ml) compared with heterozygous (arginine/proline) individuals (6729+/-883 pg/ml; P<0.02). In patients requiring lung transplantation for a fibrotic lung condition, there was an increase in the frequency of the high-producer TGF-beta1 allele (arginine). This allele was significantly associated with pretransplant fibrotic pathology (P<0.02) (n=45) when compared with controls (n=107) and with pretransplant nonfibrotic pathology (P<0.004) (n=50). This allele was also associated with allograft fibrosis in transbronchial biopsies when compared with controls (P<0.03) and with nonallograft fibrosis (P<0.01). CONCLUSION The production of TGF-beta1 is under genetic control, and this in turn influences the development of lung fibrosis. Hence, the TGF-beta1 genotype has prognostic significance in transplant recipients.

Discrepancies between clinical and autopsy diagnosis and the value of post mortem histology; a meta-analysis and review.

The autopsy is in decline, despite the fact that accurate mortality statistics remain essential for public health and health service planning. The falling autopsy rate combined with the Coroners Review and Human Tissue Act have contributed to this decline, and to a falling use of autopsy histology, with potential impact on clinical audit and mortality statistics. At a time when the need for reform and improvement in the death certification process is so prominent, we felt it important to assess the value of the autopsy and autopsy histology. We carried out a meta‐analysis of discrepancies between clinical and autopsy diagnoses and the contribution of autopsy histology. There has been little improvement in the overall rate of discrepancies between the 1960s and the present. At least a third of death certificates are likely to be incorrect and 50% of autopsies produce findings unsuspected before death. In addition, the cases which give rise to discrepancies cannot be identified prior to autopsy. Over 20% of clinically unexpected autopsy findings, including 5% of major findings, can be correctly diagnosed only by histological examination. Although the autopsy and particularly autopsy histology are being undermined, they are still the most accurate method of determining the cause of death and auditing accuracy of clinical diagnosis, diagnostic tests and death certification.

Diagnosis of Lung Cancer in Small Biopsies and Cytology: Implications of the 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society Classification

The new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society lung adenocarcinoma classification provides, for the first time, standardized terminology for lung cancer diagnosis in small biopsies and cytology; this was not primarily addressed by previous World Health Organization classifications. Until recently there have been no therapeutic implications to further classification of NSCLC, so little attention has been given to the distinction of adenocarcinoma and squamous cell carcinoma in small tissue samples. This situation has changed dramatically in recent years with the discovery of several therapeutic options that are available only to patients with adenocarcinoma or NSCLC, not otherwise specified, rather than squamous cell carcinoma. This includes recommendation for use of special stains as an aid to diagnosis, particularly in the setting of poorly differentiated tumors that do not show clear differentiation by routine light microscopy. A limited diagnostic workup is recommended to preserve as much tissue for molecular testing as possible. Most tumors can be classified using a single adenocarcinoma marker (eg, thyroid transcription factor 1 or mucin) and a single squamous marker (eg, p40 or p63). Carcinomas lacking clear differentiation by morphology and special stains are classified as NSCLC, not otherwise specified. Not otherwise specified carcinomas that stain with adenocarcinoma markers are classified as NSCLC, favor adenocarcinoma, and tumors that stain only with squamous markers are classified as NSCLC, favor squamous cell carcinoma. The need for every institution to develop a multidisciplinary tissue management strategy to obtain these small specimens and process them, not only for diagnosis but also for molecular testing and evaluation of markers of resistance to therapy, is emphasized.

Active Lung Fibrosis up to 17 Years after Chemotherapy with Carmustine (BCNU) in Childhood

BACKGROUND Carmustine (BCNU) is an anticancer drug known to produce pulmonary fibrosis as a side effect within three years of treatment. It is not known whether pulmonary fibrosis can appear later. METHODS To investigate the clinical range of this side effect, we studied the survivors among 31 children treated with carmustine for brain tumors between 1972 and 1976. Fourteen had died of their tumor; of the remaining 17, 6 had died of lung fibrosis--2 within 3 years of treatment and 4 from 8 to 13 years after treatment. This report focuses primarily on the 11 survivors, 8 of whom were available for detailed study 13 to 17 years (mean, 14) after treatment. RESULTS Of the eight survivors studied, six had abnormal chest radiographs showing predominantly upper-zone fibrotic changes. These patients also had abnormal CT scans, showing a previously undescribed pattern of upper-zone fibrosis. All the survivors studied had restrictive spirometric defects (mean [+/- SD] vital capacity, 54 +/- 19 percent of the predicted value). Bronchoalveolar-lavage fluid contained abnormal proportions of specific macrophage subgroups. Light and electron microscopy in six patients revealed interstitial fibrosis and elastosis with damage to epithelial and endothelial cells. Four patients had symptoms (shortness of breath, cough, or both). CONCLUSIONS Carmustine chemotherapy in childhood causes lung fibrosis that may remain asymptomatic for many years or become symptomatic at any time.

Transforming growth factor beta (TGF-β) and obliterative bronchiolitis following pulmonary transplantation

BACKGROUND Obliterative bronchiolitis (OB) characterised by small-airway fibrosis is a major cause of morbidity and mortality after lung transplantation. TGF-beta has been implicated in the pathogenesis of fibrosis. METHODS We immunohistochemically examined 380 transbronchial biopsies (from 91 pulmonary transplants) using TGF-beta polyclonal antibodies. OB and interstitial fibrosis were diagnosed and graded in all biopsies. Other potential histologic and clinical risk factors for OB were analysed. RESULTS Procedures were heart and lung (n = 32), bilateral sequential lung (n = 18), and single lung transplantation (n = 41). The incidence of OB in this group was 28.5%. In all patients with OB, TGF-beta was immunolocalized in the airways and lung parenchyma. TGF-beta expression was greater in OB patients (median score 8, range 5-12) in comparison to patients without OB (median score 4, range 1-13), p < .0001. Positive TGF-beta staining preceded the histologic confirmation of OB by 6 to 18 months. The development of OB was associated with two HLA mismatches at the A locus (p = .02); recurrent acute rejection episodes (p < .0005); lymphocytic bronchiolitis (p = .0001); and tissue eosinophilia, regardless of the rejection grade (p < .0001). CONCLUSIONS Increased expression of TGF-beta is a risk factor for the development of OB. Other risk factors are recurrent acute rejection, lymphocytic bronchiolitis, tissue eosinophilia, and two mismatches at the HLA-A locus. This suggests that the pathogenesis of progressive small airway fibrosis characteristic of OB may be inflammatory damage, followed by an aberrant repair process due to excessive TGF-beta production following allograft injury. Hence, modulation of TGF-beta levels or function by antagonists may represent an important approach to control OB.

Expression of epidermal growth factor receptor (EGF-R) in human lung tumours

Epidermal growth factor receptor (EGF-R) expression was assessed in 63 lung tumour samples with a monoclonal antibody (EGF-R1) by indirect immunoperoxidase staining on cryostat sections. All 15 small cell lung cancer samples were negative whereas over 80% of the 48 non small lung cancer stained positively. In 30 bronchial biopsies two monoclonal antibodies against the cytoplasmic part of the EGF-R were evaluated. These antibodies showed weaker staining than EGF-R1. No additional or enhanced staining as compared with EGF-R1 was observed, suggesting a lack of enhanced expression of a truncated EGF-R analogous to the v-erb-B oncogene product. Monoclonal antibodies against the EGF-R may be helpful diagnostically in differentiating small cell from non small cell lung cancer and may also be important in elucidating biological differences in primary lung cancer.

Bronchioloalveolar carcinoma and lung adenocarcinoma: the clinical importance and research relevance of the 2004 World Health Organization pathologic criteria.

Introduction: Advances in the pathology and computed tomography (CT) of lung adenocarcinoma and bronchioloalveolar carcinoma (BAC) have demonstrated important new prognostic features that have led to changes in classification and diagnostic criteria. Methods: The literature and a set of cases were reviewed by a pathology/CT review panel of pathologists and radiologists who met during a November 2004 International Association for the Study of Lung Cancer/American Society of Clinical Oncology consensus workshop in New York. The group addressed the question of whether sufficient data exist to modify the 2004 World Health Organization (WHO) classification of adenocarcinoma and BAC to define a “minimally invasive” adenocarcinoma with BAC. The problems of diffuse and/or multicentric BAC and adenocarcinoma were evaluated. Results: The clinical concept of BAC needs to be reevaluated with careful attention to the new 2004 WHO criteria because of the major clinical implications. Existing data indicate that patients with solitary, small, peripheral BAC have a 100% 5-year survival rate. The favorable prognostic impact of the restrictive criteria for BAC is already being detected in major epidemiologic data sets such as the Surveillance Epidemiology and End-Results registry. Most lung adenocarcinomas, including those with a BAC component, are invasive and consist of a mixture of histologic patterns. Therefore, they are best classified as adenocarcinoma, mixed subtype. This applies not only to adenocarcinomas with a solitary nodule presentation but also to tumors with a diffuse/multinodular pattern. The percentage of BAC versus invasive components in lung adenocarcinomas seems to be prognostically important. However, at the present time, a consensus definition of “minimally invasive” BAC with a favorable prognosis was not recommended by the panel, so the 1999/2004 WHO criteria for BAC remain unchanged. In small biopsy specimens or cytology specimens, recognition of a BAC component is possible. However, it is not possible to exclude an invasive component. The diagnosis of BAC requires thorough histologic sampling of the tumor. Conclusion: Advances in understanding of the pathology and CT features of BAC and adenocarcinoma have led to important changes in diagnostic criteria and classification of BAC and adenocarcinoma. These criteria need to be uniformly applied by pathologists, radiologists, clinicians, and researchers. The 2004 WHO classification of adenocarcinoma is readily applicable to research studies, but attention needs to be placed on the relative proportion of the adenocarcinoma subtypes. Other recently recognized prognostic features such as size of scar, size of invasive component, or pattern of invasion also seem to be important. More work is needed to determine the most important prognostic pathologic features in lung adenocarcinoma.

Malignant pleural mesothelioma and epidermal growth factor receptor (EGF-R). Relationship of EGF-R with histology and survival using fixed paraffin embedded tissue and the F4, monoclonal antibody

The expression of epidermal growth factor receptor (EGF-R) in 34 formalin fixed paraffin embedded specimens of malignant mesothelioma was examined using the F4 antibody. Eight samples of reactive pleura showed homogenous cytoplasmic staining with the antibody. EGF-R positive cells (greater than or equal to 5%) were found in 68% of the mesotheliomas examined. EGF-R positivity was more commonly seen in the epithelial histological subtype than in the sarcomatous or mixed subtypes. Patients with less than 5% of mesothelioma cells staining positive for EGF-R had a significantly shorter survival (median 299 days) compared with patients whose tumours had a greater number of cells positive for EGF-R (median 446 days) (P = 0.04). However, when the histological subgroup was also taken into consideration (epithelial type had a significantly longer survival than the sarcomatous or mixed) the survival difference in relation to EGF-R positivity was no longer significant (P = 0.08). EGF-R could not be used to distinguish between malignant and benign mesothelial tissue and was not an independent prognostic factor for survival.