Travis, William D.

Context .—Malignant mesothelioma (MM) is an uncommon tumor that can be difficult to diagnose. Objective .—To provide updated practical guidelines for the pathologic diagnosis of MM. Data Sources .—Pathologists involved in the International Mesothelioma Interest Group and others with an interest in the field contributed to this update. Reference material includes peer-reviewed publications and textbooks. Conclusions .—There was consensus opinion regarding (1) distinction of benign from malignant mesothelial proliferations (both epithelioid and spindle cell lesions), (2) cytologic diagnosis of MM, (3) key histologic features of pleural and peritoneal MM, (4) use of histochemical and immunohistochemical stains in the diagnosis and differential diagnosis of MM, (5) differentiation of epithelioid MM from various carcinomas (lung, breast, ovarian, and colonic adenocarcinomas, and squamous cell and renal cell carcinomas), (6) diagnosis of sarcomatoid mesothelioma, (7) use of molecular markers in the diagnosis of MM, (8) electron microscopy in the diagnosis of MM, and (9) some caveats and pitfalls in the diagnosis of MM. Immunohistochemical panels are integral to the diagnosis of MM, but the exact makeup of panels used is dependent on the differential diagnosis and on the antibodies available in a given laboratory. Immunohistochemical panels should contain both positive and negative markers. It is recommended that immunohistochemical markers have either sensitivity or specificity greater than 80% for the lesions in question. Interpretation of positivity generally should take into account the localization of the stain (eg, nuclear versus cytoplasmic) and the percentage of cells staining (>10% is suggested for cytoplasmic membranous markers). These guidelines are meant to be a practical reference for the pathologist.

Abstract Rationale Idiopathic pulmonary fibrosis (IPF) and other idiopathic interstitial pneumonias (IIPs) have similar clinical and radiographic features, but their histopathology, response to therapy, and natural history differ. A surgical lung biopsy is often required to distinguish between these entities. Objectives We sought to determine if clinical variables could predict a histopathologic diagnosis of IPF in patients without honeycomb change on high-resolution computed tomography (HRCT). Methods Data from 97 patients with biopsy-proven IPF and 38 patients with other IIPs were examined. Logistic regression models were built to identify the clinical variables that predict histopathologic diagnosis of IPF. Measurements and Main Results Increasing age and average total HRCT interstitial score on HRCT scan of the chest may predict a biopsy confirmation of IPF. Sex, pulmonary function, presence of desaturation, or distance walked during a 6-minute walk test did not help discriminate pulmonary fibrosis from other IIPs. Conclusions Clinical data may be used to predict a diagnosis of IPF over other IIPs. Validation of these data with a prospective study is needed.

Abstract Purpose: The eukaryotic translation initiation factor complex 4E (eIF4E) is downstream in the mammalian target of rapamycin (mTOR) pathway. This study explored expression of eIF4E and its relationship with the PTEN/AKT and RAS/MEK/ERK pathways in non–small cell lung carcinoma (NSCLC). Experimental Design: The status of phosphorylated eIF4E (p-eIF4E), phosphorylated AKT (p-AKT), PTEN, phosphorylated tuberin (p-TSC2), phosphorylated mTOR (p-mTOR), phosphorylated S6 (p-S6), and phosphorylated Erk1/2 (p-Erk1/2) was studied using immunohistochemical analysis applied to a tissue microarray containing 300 NSCLCs. Staining results for each antibody were compared with clinical and pathologic features, and the relationship between staining results was explored. Results: Overexpression of p-eIF4E, p-AKT, p-TSC2, p-mTOR, p-S6, and p-Erk1/2 in NSCLC was found in 39.9%, 78.8%, 5.1%, 46.7%, 27.1%, and 16.6% of tumors, respectively. The phenotype of p-eIF4E correlated positively with that of p-AKT, p-TSC2, and p-S6 (P < 0.001). Overall survival in NSCLC patients was significantly shorter in cases with overexpression of p-eIF4E and p-AKT alone and in combination (log-rank P < 0.001, each). Cases with underexpression of PTEN were limited (6.4%), and this phenotype did not correlate with any clinical variable. In cluster analysis, the p-AKT/p-mTOR/p-eIF4E/p-S6–positive group had significantly shorter survival compared with the survival of all cases (P < 0.001). Multivariate analysis showed that p-eIF4E overexpression is an independent prognostic factor for NSCLC (P = 0.004). Conclusions: This study shows that p-eIF4E expression in addition to p-AKT predicts poor prognosis in NSCLC. Moreover, the correlation between expression of p-eIF4E with p-AKT, as well as p-TSC2 and p-S6, indicates that eIF4E activation through the AKT pathway plays an important role in the progression of NSCLC. Clin Cancer Res; 16(1); OF1–9

Abstract Rationale Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea, impaired gas exchange, and ultimate mortality. Objectives To test the hypothesis that maximal oxygen uptake during cardiopulmonary exercise testing at baseline and with short-term longitudinal measures would predict mortality in patients with idiopathic pulmonary fibrosis. Methods Data from 117 patients with IPF and longitudinal cardiopulmonary exercise tests were examined retrospectively. Survival was calculated from the date of the first cardiopulmonary exercise test. Measurements and Main Results Patients with baseline maximal oxygen uptake less than 8.3 ml/kg/min had an increased risk of death (n = 8; hazard ratio, 3.24; 95% confidence interval, 1.10–9.56; P = 0.03) after adjusting for age, gender, smoking status, baseline forced vital capacity, and baseline diffusion capacity for carbon monoxide. We were unable to define a unit change in maximal oxygen uptake that predicted survival in our cohort. Conclusions We conclude that a threshold maximal oxygen uptake of 8.3 ml/kg/min during cardiopulmonary exercise testing at baseline adds prognostic information for patients with IPF.

Abstract Rationale The 2002 American Thoracic Society/European Respiratory Society classification of idiopathic interstitial pneumonias identified nonspecific interstitial pneumonia (NSIP) as a provisional diagnosis. Concern was expressed that NSIP was a “wastebasket” category, difficult to distinguish from other idiopathic interstitial pneumonias. Objectives The following questions were addressed: (1) Is idiopathic NSIP a distinct entity? 2) If so, what are its clinical, radiologic and pathologic characteristics? (3) What is the role of radiology and pathology in establishing the diagnosis? (4) To make a diagnosis of idiopathic NSIP, what other disorders need to be excluded and how should this be done? Methods Investigators who had previously reported cases of idiopathic NSIP were invited to submit cases for review (n = 305). After initial review, cases with complete clinical, radiologic, and pathologic information (n = 193) were reviewed in a series of workshops. Measurements and Main Results Sixty-seven cases were identified as NSIP. Mean age was 52 years, 67% were women, 69% were never-smokers, and 46% were from Asian countries. The most common symptoms were dyspnea (96%) and cough (87%); 69% had restriction. By high-resolution computed tomography, the lower lung zones were predominantly involved in 92% of cases; 46% had a peripheral distribution; 47% were diffuse. Most showed a reticular pattern (87%) with traction bronchiectasis (82%) and volume loss (77%). Lung biopsies showed uniform thickening of alveolar walls with a spectrum of cellular to fibrosing patterns. Five-year survival was 82.3%. Conclusions Idiopathic NSIP is a distinct clinical entity that occurs mostly in middle-aged women who are never-smokers. The prognosis of NSIP is very good.

Abstract Rationale Prostaglandin (PG) E2, a cyclooxygenase-derived lipid mediator, is a potent down-regulator of fibroblast activation in normal lung fibroblasts. Although fibroblasts from patients with idiopathic pulmonary fibrosis are known to exhibit a defect in PGE2 synthesis, there is little information about their responsiveness to this lipid mediator. Objectives To compare responses to PGE2 in normal, usual interstitial pneumonia (UIP), and other diffuse parenchymal lung disease (DPLD) fibroblasts. Methods Fibroblasts were grown in vitro from well characterized control (n = 7), UIP (n = 17), or other DPLD (n = 13) lung tissue. The effects of PGE2 on fibroblast proliferation and collagen expression were determined. Measurements and Main Results Only 3 of 12 UIP fibroblast lines exhibited PGE2-mediated inhibition of both collagen synthesis and cell proliferation, as opposed to 6 of 6 nonfibrotic control cell lines. The degree of PGE2 resistance in DPLD fibroblasts was quite variable, with UIP cells exhibiting the greatest degree of resistance to PGE2, whereas other DPLD fibroblasts manifested a degree of resistance intermediate to control and UIP. The resistance to suppression of collagen expression correlated with worse lung function. Molecular mechanisms for resistance included altered E prostanoid receptor profiles and diminished expression of the downstream kinase, protein kinase A. Conclusions The recognition that UIP fibroblasts manifest variable refractoriness to PGE2 suppression sheds new light on the activation phenotype of these cells and on the pathogenesis of fibrotic lung disease.

Abstract Rationale Treatment and prognoses of diffuse parenchymal lung diseases (DPLDs) varies by diagnosis. Obtaining a uniform diagnosis among observers is difficult. Objectives Evaluate diagnostic agreement between academic and community-based physicians for patients with DPLDs, and determine if an interactive approach between clinicians, radiologists, and pathologists improved diagnostic agreement in community and academic centers. Methods Retrospective review of 39 patients with DPLD. A total of 19 participants reviewed cases at 2 community locations and 1 academic location. Information from the history, physical examination, pulmonary function testing, high-resolution computed tomography, and surgical lung biopsy was collected. Data were presented in the same sequential fashion to three groups of physicians on separate days. Measurements and Main Results Each observer's diagnosis was coded into one of eight categories. A κ statistic allowing for multiple raters was used to assess agreement in diagnosis. Interactions between clinicians, radiologists, and pathologists improved interobserver agreement at both community and academic sites; however, final agreement was better within academic centers (κ = 0.55–0.71) than within community centers (κ = 0.32–0.44). Clinically significant disagreement was present between academic and community-based physicians (κ = 0.11–0.56). Community physicians were more likely to assign a final diagnosis of idiopathic pulmonary fibrosis compared with academic physicians. Conclusions Significant disagreement exists in the diagnosis of DPLD between physicians based in communities compared with those in academic centers. Wherever possible, patients should be referred to centers with expertise in diffuse parenchymal lung disorders to help clarify the diagnosis and provide suggestions regarding treatment options.

Abstract Rationale and Hypothesis Idiopathic pulmonary fibrosis is a fatal disease with a variable rate of progression. We hypothesized that changes in distance walked and quantity of desaturation during a six-minute-walk test (6MWT) would add prognostic information to changes in FVC or diffusing capacity for carbon monoxide. Methods One hundred ninety-seven patients with idiopathic pulmonary fibrosis were evaluated. Desaturation during the 6MWT was associated with increased mortality even if a threshold of 88% was not reached. Baseline walk distance predicted subsequent walk distance but was not a reliable predictor of subsequent mortality in multivariate survival models. The predictive ability of serial changes in physiology varied when patients were stratified by the presence/absence of desaturation ⩽ 88% during a baseline 6MWT. For patients with a baseline saturation ⩽ 88% during a 6MWT, the strongest observed predictor of mortality was serial change in diffusing capacity for carbon monoxide. For patients with saturation > 88% during their baseline walk test, serial decreases in FVC and increases in desaturation area significantly predicted subsequent mortality, whereas decreases in walk distance and in diffusing capacity for carbon monoxide displayed less consistent statistical evidence of increasing mortality in our patients. Conclusion These data highlight the importance of stratifying patients by degree of desaturation during a 6MWT before attributing prognostic value to serial changes in other physiologic variables.

Abstract We evaluated somatic genetic alterations in the kinase domain of the EGFR gene in the tumors of 219 non–small cell lung cancer patients of primarily Caucasian and African American origins. We identified 26 patients (12%) whose tumors had a mutation in the EGFR gene, and 11 (5%) patients carried novel genomic variations consistent with germ-line polymorphisms. All but one mutation were identified in Caucasian patients affected with adenocarcinoma. EGFR mutations were more frequent in women and in nonsmokers, but a significant portion of the affected patients were men (12 of 26) and current or past smokers accounted for half of the patients affected (13 of 26). Screening subjects with EGFR mutations may identify patients whose tumors could respond to targeted therapy using tyrosine kinase inhibitors.