Pathologist-initiated reflex testing for biomarkers in non-small-cell lung cancer: expert consensus on the rationale and considerations for implementation.

Biomarker tests in lung cancer have been traditionally ordered by the treating oncologist upon confirmation of an appropriate pathological diagnosis. The delay this introduces prolongs yet further what is already a complex, multi-stage, pre-treatment pathway and delays the start of first-line systemic treatment, which is crucially informed by the results of such analysis. Reflex testing, in which the responsibility for testing for an agreed range of biomarkers lies with the pathologist, has been shown to standardise and expedite the process. Twelve experts discussed the rationale and considerations for implementing reflex testing as standard clinical practice.

EUELC project: a multi-centre, multipurpose study to investigate early stage NSCLC, and to establish a biobank for ongoing collaboration.

The European Early Lung Cancer (EUELC) project aims to determine if specific genetic alterations occurring in lung carcinogenesis are detectable in the respiratory epithelium. In order to pursue this objective, nonsmall cell lung cancer (NSCLC) patients with a very high risk of developing progressive lung cancer were recruited from 12 centres in eight European countries: France, Germany, southern Ireland, Italy, the Netherlands, Poland, Spain and the UK. In addition, NSCLC patients were followed up every 6 months for 36 months. A European Bronchial Tissue Bank was set up at the University of Liverpool (Liverpool, UK) to optimise the use of biological specimens. The molecular-pathological investigations were subdivided into specific work packages that were delivered by EUELC Partners. The work packages encompassed mutational analysis, genetic instability, methylation profiling, expression profiling utilising immunohistochemistry and chip-based technologies, as well as in-depth analysis of FHIT and RARbeta genes, the telomerase catalytic subunit hTERT and genotyping of susceptibility genes in specific pathways. The EUELC project engendered a tremendous collaborative effort, and it enabled the EUELC Partners to establish protocols for assessing molecular biomarkers in early lung cancer with the view to using such biomarkers for early diagnosis and as intermediate end-points in future chemopreventive programmes.

hMLH1 and hMSH2 expression correlates with allelic imbalance on chromosome 3p in non-small cell lung carcinomas.

DNA mismatch repair genes have been implicated in the pathogenesis and predisposition of certain malignancies through a mutator phenotype. In this study, we investigated, in 150 non-small cell lung carcinomas, the expression levels of hMLH1 and hMSH2 proteins in relation to loss of heterozygosity on chromosomes 3p and 2p, the mutational status of these genes' promoters and the hot spot exons. We have demonstrated that 88 of 150 (58.6%) tumor specimens had reduced expression levels of the hMLH1 protein, whereas 85 of 147 (57.8%) specimens had reduced expression levels of the hMSH2 protein. Reduced expression levels of both proteins were observed in 51 of 150 (34%) specimens. In adenocarcinomas, the reduction of hMSH2 expression was more frequently observed than that of hMLH1 (P<0.003), whereas in squamous cell carcinoma of the lung hMLH1 expression was more frequently reduced than hMSH2 (P<0.006). Reduced expression of hMLH1correlated with allelic imbalance on loci D3S1289 (P<0.0002) and D2S391 (P<0.05). It is of note that an inverse correlation was found between hMSH2 reduced expression and loss of heterozygosity at locus D3S1300 (P = 0.016). In addition, hMLH1 reduced expression was more frequently associated with heavy smokers, assessed by daily tobacco uptake (P = 0.018) and total smoking exposure (pack-years; P<0.05). In addition, a correlation between hMLH1 reduced expression and nodal metastasis in squamous cell carcinoma of the lung was observed (P = 0.015). No mutations were identified in the promoters or exons examined in these two genes. These findings indicate that hMLH1 and hMSH2 gene inactivation is a common event in the development of non-small cell lung carcinoma and allelic loss seems to be a major genetic event involved in hMLH1 silencing. In addition, we propose that a putative negative regulator of hMSH2 gene may be located at the locus 3p14.

Cancer-specific genomic instability in bronchial lavage: a molecular tool for lung cancer detection.

We examined genomic instability in DNA from 80 bronchial lavage samples from patients with lung cancer and individuals with no malignant lung disease. We used a multiplex assay of eight fluorescent-tagged microsatellite markers that have a very high incidence of allelic imbalance in lung tumors. When genomic instability at individual loci was analyzed statistically against diagnosis, markers D3S1289 (P = 0.033), D3S1300 (P = 0.001), D13S171 (P = 0.009), and D17S2179E (P = 0.017) demonstrated significantly higher frequency of instability in bronchial lavage specimens from lung cancer cases than those with nonmalignant conditions. In contrast, markers D9S157, D9S161, D13S153, and D5S644 demonstrated lower specificity (P > 0.05) for lung tumors. These results suggest that genomic instability in some loci may be related to high proliferation rates but not necessarily to cell commitment to malignancy. When genomic instability was scored with only the four cancer-specific markers, the assay produced a sensitivity of 73.9% and a specificity of 76.5%. On combining the results from the cytological examination and the molecular assay, the sensitivity reached 82.6%. These results indicate that in our efforts to investigate genomic instability as a potential marker for the early detection of lung cancer, we need to identify cancer-specific genomic instability markers. This paper has shown that these first four markers may be considered to form an individual set of cancer-specific genomic instability markers.

Multiple target sites of allelic imbalance on chromosome 17 in Barrett's oesophageal cancer.

Twelve Barrett's adenocarcinomas have been analysed for the occurrence of allelic imbalance (LOH) on chromosome 17 using 41 microsatellite markers. This study provides evidence for 13 minimal regions of LOH, six on 17p and seven on 17q. Four of these centre in the vicinity of the known tumour suppressor genes (TSGs) TP53 (17p13.1), NFI (17q11.2), BRCA1 (17q21.1), and a putative TSG (17p13.3). The tumours all displayed relatively small regions of LOH (1-10 cM), and in several tumours extensive regions of LOH were detected. One tumour displayed only two very small regions of LOH; 17p11.2 and 17p13.1. The frequency of allelic imbalance has been calculated based on the LOH encompassing only one minimal region, and based on all the LOH observations. By both evaluations the highest LOH frequencies were found for regions II (p53), III (17p13.1 centromeric to p53), IV (17p12), V (17p11.2) and VII (NF1, 17q11.2). Our data supports the existence of multiple TSGs on chromosome 17 and challenges the view that p53 is the sole target of LOH on 17p in Barrett's adenocarcinoma.

The evolution of loss of heterozygosity on chromosome 17 during the progression to barrett's adenocarcinoma involves a unique combination of target sites in individual specimens.

We have previously identified thirteen common minimally deleted regions (MRs) on chromosome 17 in twelve Barrett's esophageal adenocarcinoma (BOA) specimens using 41 precisely mapped microsatellite markers (Dunn et al., Oncogene, 17: 987-993, 1999). The aim of the present study has been to identify the earliest sites of loss on this chromosome that arise and persist during the progression to BOA. This has been undertaken by the analysis of multiple carefully microdissected tissue samples from each of five esophagectomy specimens, several of which contained identifiable premalignant tissue. Our data demonstrate a stepwise accumulation of loss in each analyzed specimen, consistent with a single clonal pathway in four specimens and several coexisting pathways in one specimen. Several clonal anomalies (loss preceding heterozygosity and variable intrasample degrees of loss at different markers) were also observed. Within extensively deleted regions of the tumor (seen in three specimens), small deletions were detected in premalignant tissue, predominantly at the site of our identified MRs, and these losses were seen to expand and merge during the progression to BOA. Clonal losses at MRs were first detected in tissue showing early changes histologically, including Barrett's intestinal metaplasia and intermediate-grade dysplasia. Our results provide further support for many of the MRs we have previously identified, thereby adding to evidence for the existence of multiple novel cancer-associated genes on chromosome 17 involved in the development of BOA.

Morphological changes in the pituitary and thyroid of the rat in hypobaric hypoxia.

When a group of adult male Wistar rats was exposed to a barometric pressure of 380 mmHg for 28 days in an hypobaric chamber, profound changes occurred in their hypothalamic-pituitary-thyroidal axes in comparison with normobaric controls. The thyroid glands of the hypoxic animals had an inactive appearance, comprising large colloid-filled follicles lined by low epithelium. The thyrotrophs of the pars distalis of the pituitary glands were markedly decreased in number. They occupied only 0.41% of the total cell population in contrast with 1.34% in the controls (P less than 0.001); a total population which is itself decreased in the hypoxic animals. Classical 'thyroidectomy cells' were not seen. These observations support previous studies which indicate suppression of thyroid function in an hypoxic environment, and tend to suggest that this is a consequence of a direct effect of hypoxia on the hypothalamus or pituitary gland, rather than on the thyroid itself.

Effects of hypobaric hypoxia on the Leydig cell population of the testis of the rat.

A group of ten young adult male Wistar albino rats was exposed to hypobaric hypoxia at a barometric pressure of 380 mmHg for 28 days. After this period their testes were of smaller weight (and volume) in comparison with matched controls (1.220 vs 1.553 g; P less than 0.005). Histological examination revealed degeneration and sloughing of spermatogenic cells in occasional tubules. Quantitative methods also revealed a marked difference in the volume of the testis occupied by Leydig cells. These were of a significantly smaller total volume in the hypoxic animals (0.046 vs 0.083 ml; P less than 0.001) and this could not be accounted for merely by the smaller overall testicular volume.

Telomerase activity in non-small cell lung carcinomas correlates with smoking status.

Human telomerase is a ribonucleoprotein DNA polymerase which maintains the telomeric region of human chromosomes and has been detected in all types of human cancer tested. We used the telomeric repeat amplification protocol (TRAP) assay to examine 71 non-small cell lung carcinomas (NSCLC) and their adjacent normal tissue. Telomerase activity was detected in 61 (86%) of the 71 NSCLC examined but not in any of the matched normal lung tissues. A significant correlation was found between the presence of telomerase activity and current smoking status at the time of diagnosis (p=0. 0076). In addition, a trend was found between telomerase activity and smoking exposure (p=0.06). Our findings demonstrate that telomerase activity is a common phenomenon in NSCLC cases but not in the normal lung. However, certain cases in former smokers may follow a telomerase independent pathway.

Orthostatic hypotension and vasodilatory peptides in bronchial carcinoma.

AIM: To determine whether inappropriately secreted vasodilatory peptides have a role in the pathogenesis of orthostatic (postural) hypotension, a recognised paraneoplastic effect of bronchial malignancies usually attributed to immune mediated destruction of autonomic ganglia. METHODS: Serum concentrations of three vasodilatory peptides, atrial natriuretic peptide (ANP), vasoactive intestinal polypeptide (VIP) and calcitonin gene related peptide (CGRP), were measured in 111 patients with bronchial carcinoma and 35 controls prospectively screened for orthostatic hypotension (> 20 mmHg drop in systolic blood pressure on repeated occasions on standing from the supine position) and in whom other causes of this condition were excluded. RESULTS: Twenty two (20%) patients with carcinoma and two (6%) controls had orthostatic hypotension according to the criteria used. Serum concentrations of ANP, VIP and CGRP were elevated above normal in, respectively, 25 (23%), 10 (9%) and eight (7%) patients with carcinoma and in six (18%), zero and three (9%) controls. There was no correlation between orthostatic hypotension and concentrations of any of the vasodilatory peptides. CONCLUSION: Elevated serum concentrations of ANP and CGRP were no more frequent in subjects with bronchial carcinoma than in controls and could not be attributed to the tumour, although there was a possible association for VIP. Orthostatic hypotension was more common in patients with carcinoma, but there was no evidence that the peptides measured played a role in its pathogenesis.

Exposure to cigarette smoke and expression of the protein encoded by the p53 gene in bronchial carcinoma.

Mutation of the onco-suppressor gene encoding the protein known as p53 may cause synthesis of a mutant p53 protein which can bind to and inactivate its wild-type equivalent. This protein is detectable in many malignant neoplasms, including bronchial carcinoma, and has been associated with cigarette smoking. Of 59 tissue biopsy specimens of primary bronchial malignancies immunolabeled for p53 by the avidin-biotin technique using the antibodies PAb 1801, CM1, and D07, 13 (22%) expressed the protein. Of these 13 patients, 10 (77%) smoked more than 20 cigarettes a day and their mean total exposure was 53 pack-years. Corresponding figures for those with p53-negative tumors were 21 (46%) smoking more than 20 cigarettes a day with a mean total exposure of 36 pack-years. There was, however, no difference between the groups in total duration of exposure (46 vs. 47 years). Although p53 was expressed more commonly in adenocarcinoma (30% of 10) and squamous carcinoma (28% of 29) than in small cell tumors (10% of 20), this could be accounted for by the smoking history. This study supports a relationship between mutations of the p53-encoding gene associated with overexpression of its protein product and intensity of exposure to cigarette smoke.

Pulmonary neuroendocrine cell system in pediatric and adult lung disease.

In humans lungs affected by naturally occurring pulmonary disease, the pulmonary neuroendocrine cell system, which is normally arranged in a sparse but even distribution throughout the respiratory tract, increases in size. It is likely that the stimulus for this is pulmonary injury and that its purpose is the paracrine regulation of the restoration of pulmonary tissues to their normal state, an hypothesis supported by studies of animal lungs subjected to experimental injury as well as of the development of human and animal lungs in utero. Initially, this increase involves the development of interrupted rows of neuroendocrine cells. In the later stages, however, development of more disorderly intraepithelial aggregates can occur and the small, locally invasive neuroendocrine cell lesions known as tumourlets may occasionally result. Both of these latter structures often contain secretory products not found in the neuroendocrine cells of normal human lungs, probably indicating a derangement of what appears to be a fundamentally physiological response. It is likely that, in some circumstances, this disorderly change may contribute to pulmonary disease as well as being the result of it.

Low levels of ras p21 oncogene expression correlates with clinical outcome in head and neck squamous cell carcinoma.

We have previously demonstrated that the Ha-ras and the Ki-ras oncogenes are overexpressed in squamous cell carcinoma of the head and neck. In this study we have used the Y13-259 monoclonal antibody to p21 ras to determine if expression of the ras oncoprotein correlates with any of the clinico-pathological parameters or with survival in 69 patients with squamous cell carcinoma of the head and neck. Forty-four specimens were from patients with previously untreated tumours and 25 from patients with previously treated disease. We have found a correlation between low levels of ras expression and the disease-free survival period in patients with previously untreated tumours. Three per cent of the patients with ras negative staining were alive 60 months after diagnosis, whereas 54 per cent of the patients with positive staining were still alive after the same time period (P less than 0.05).

Allelic imbalance at the DNA mismatch repair loci, hMSH2, hMLH1, hPMS1, hPMS2 and hMSH3, in squamous cell carcinoma of the head and neck.

BACKGROUND: Squamous cell carcinoma of the head and neck (SCCHN) is one of the 10 most frequently occurring cancers in the world. Defective mismatch repair, as exhibited by the phenomenon of microsatellite instability, has been observed in SCCHN although no reports of mismatch repair gene mutations or altered protein expression have been published. In a variety of microsatellite instability (MSI) positive cancers where mutations in the mismatch repair (MMR) genes were not observed, allelic imbalance at the loci of the MMR genes was prevalent. OBJECTIVE: To investigate whether allelic imbalance at the MMR genetic loci contributes to the development of SCCHN. MATERIALS AND METHODS: 35 matched normal/tumour SCCHN pairs were studied using 29 microsatellite markers located within and adjacent to six known DNA mismatch repair genes. In addition, mutational analysis and protein expression of hMSH2 and hMLH1 were investigated. RESULTS AND CONCLUSIONS: We demonstrated that 36 and 17% of the analysed SCCHN specimens exhibited allele imbalance at the hMLH1 and hMSH3 genetic loci, respectively. Allelic instability at these two loci was found to be correlated with the MSI status of the SCCHN tumours. Allelic instability was found to be uncommon at the other MMR gene loci analysed. One mutation was found in hMSH2 and none in hMLH1 in this series of tumours. 23 of 24 (96%) of the examined SCCHN tumours showed reduced expression of either hMSH2 or hMCH1 genes. Allelic instability in the MMR genes, hMLH1 and hMSH3, is proposed to be involved in the aetiology of SCCHN tumours.

C-erbB-2 expression in squamous cell carcinoma of the head and neck.

Seventy-five squamous cell carcinomas of the head and neck were analysed for c-erbB-2 expression using immunohistochemical techniques with four different c-erbB-2 antibodies. No membrane staining was seen in any of the squamous cell carcinomas studied with any of the antibodies; however, c-erbB-2 cytoplasmic staining was seen in 60 per cent of the tumours. The significance of cytoplasmic staining is discussed and that it may possibly represent elevated c-erbB-2 expression in squamous cell carcinomas. C-erbB-2 cytoplasmic staining was also observed in 10 of 23 normal specimens obtained from the resection margin of the tumours. No correlations were found between positive c-erbB-2 cytoplasmic staining and any of the clinicopathological parameters or survival.

c-myc oncoprotein in bronchial carcinoma: expression in all major morphological types.

We have studied the prevalence of a 62 kd protein product of the c-myc oncogene in tissue biopsies from 79 primary bronchial carcinomata using the monoclonal antibody Myc 1-9E10 and the avidin-biotin complex (ABC) technique. This oncoprotein was strongly expressed in 43% of 37 squamous lesions, 29% of 14 adenocarcinomata, 42% of 7 non-small cell lesions not further classifiable and 19% of 21 small cell neoplasms, all of classical morphology. There was no statistical difference between groups in the prevalence of its expression, nor was it related to survival. This oncoprotein is commonly expressed in non-small cell as well as small cell bronchial carcinomata and, in the latter, is not confined to those variant tumours which possess a "large cell" morphology and carry a poor prognosis.

Effect of prenatal glucocorticoids on pulmonary vascular muscularisation in nitrofen-induced congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Pulmonary hypertension (PH) contributes significantly to the mortality of congenital diaphragmatic hernia (CDH). Pulmonary vascular changes in CDH include a reduced vascular bed with increased arterial medial wall thickness and peripheral extension of muscle into intraacinar vessels. Antenatal steroids improve biochemical immaturity, lung compliance, and morphology in experimental CDH animals. The aim of this study was to examine the effects of prenatal glucocorticoid therapy on pulmonary artery muscularisation in CDH rats. METHODS: CDH was induced in fetal rats by the maternal administration of 100 mg of nitrofen by gavage on day 9.5 of gestation (term, day 22). Control animals received olive oil (OO). Dexamethasone (Dex, 0.25 mg/kg) or normal saline (NS) was given by intraperitoneal injection on days 18.5 and 19.5, and fetuses were delivered by caesarean section on day 21.5. Lung sections from five fetuses in each of four experimental groups were studied by a blinded investigator- OO-NS controls, CDH-NS, CDH-Dex, and non-CDH-NS. The external diameter (ED), medial wall thickness (MT), percent of medial wall thickness, and wall structure were evaluated from preacinar arteries accompanying conducting airways, and the intraacinar arterioles associated with the respiratory bronchi and saccules. RESULTS: In the preacinar arteries, CDH-NS animals had a significantly increased MT percentage compared with OO-NS controls (21.2+/-8.8 v 17.8+/-10.3, P = .0001). CDH-Dex rats had a lower MT percentage than CDH-NS rats (15.5+/-6.7 v 21.2+/-8.8, P = .0001). In the intraacinar region, CDH-Dex fetuses had a reduced percentage of muscularised intraacinar blood vessels compared with CDH-NS and OO-NS controls (10% v 24% and 28%, respectively, P = .01). Dexamethasone-treated CDH pups also displayed a significantly lower MT percentage of the intraacinar arteries compared with CDH-NS and OO-NS animals (15.7+/-13 v 23.4+/-9 and 25.4+/-12, P = .003). CONCLUSIONS: Medial hypertrophy is present in the preacinar but not the intraacinar blood vessels of CDH rats before birth. Dexamethasone inhibits medial hypertrophy and reduces the number of muscularised intraacinar vessels. Antenatal glucocorticoids may reduce the risk of PH developing in human newborns with antenatally diagnosed CDH.

Pulmonary endocrine cells in native Peruvian guinea-pigs at low and high altitude.

The role of pulmonary endocrine cells is unclear, but those which are aggregated into innervated clusters are probably chemoreceptors, responding to hypoxia in the airways, whereas solitary endocrine cells are probably quite different in their function. There were significantly more clusters of endocrine cells in the lungs of a group of 10 indigenous Peruvian guinea-pigs considered to be adapted to high altitude, in comparison with controls from sea-level, whereas there was no difference in the number of solitary cells. It is concluded that, whereas the clusters are indeed responding to and affected by hypoxia, the solitary cells are not, and play a distinct and possibly trophic role in the lung.

Basal cell carcinoma with hepatic metastases.

A case of metastatic basal cell carcinoma is presented which illustrates precisely the type of lesion most likely to metastasise to distant sites. The primary growth had been present for over 20 years at presentation, was in the middle third of the face, was widely invasive locally extending to involve bone, and was subject to repeated partially successful attempts at eradication. Histologically it was of the metatypical subtype. All are risk factors for metastasis of basal cell carcinoma which, in this case, eventually developed to the liver.