Primary lung adenocarcinoma: characteristics by smoking habit and sex.

The incidence of adenocarcinoma is increasing, particularly among females. We sought to assess the role of tobacco consumption in clinical presentation according to sex. In this retrospective study, 848 patients diagnosed between 1997 and 2006 at Grenoble University Hospital (Grenoble, France) were stratified into four groups according to smoking habits. Differences between sexes and two contrasting female profiles emerged. Female current smokers were younger than female never-smokers (median 51 versus 69 yrs; p < 0.001), more often had surgery (62.7% versus 39%; p = 0.01) and had a median (95% CI) estimated survival of 26.2 (18.1-49.2) versus 15.1 (12.8-22.2) months (p = 0.002). Both groups had similar survival when taking treatment into account. Among males, smoking did not influence presentation. Male current smokers were older than female current smokers (median 59 yrs; p < 0.001) and fewer had surgery (48.8%; p = 0.015), although the percentage of stage IIIb-IV disease was similar (53% and 46%; nonsignificant) and they had a poorer estimated survival of 14.3 (13.0-18.5) months (p = 0.0024). Males smoked more than females (median 41 versus 30 pack-yrs; p < 0.001). Quitting smoking delayed age at diagnosis by 11 yrs for females (p = 0.0035) and 8 yrs for males (p < 0.001). Our results support the hypothesis that carcinogenesis differs between males and females, and between female smokers and never-smokers.

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.

[Pathogenesis and treatment of vascular calcification in CKD]. / Invecchiamento cardiovascolare nel soggetto uremico: nuove acquisizioni.

Increased vascular calcification is a major cause of cardiovascular events in patients with chronic kidney disease (CKD). It is the result of an active ossification process counteracted by ''bone'' proteins such as osteopontin, alkaline phosphatase, osteoprotegerin, and osteocalcin. Chronic kidney disease - mineral and bone disorder (CKD-MBD) is a systemic disorder of mineral and bone metabolism that occurs in CKD. In addition to abnormalities in the serum calcium and phosphate profile, CKD-MBD is characterized by abnormalities of bone turnover, mineralization, volume and growth as well as vascular calcification. Considering that the presence and extent of vascular calcification in CKD portend a poor prognosis, many efforts have been made to shed light on this complicated phenomenon to prevent vascular calcium deposition and its progression. Indeed, careful control of calcium load, serum phosphate and parathyroid hormone along with the use of calcium-free phosphate binders and vitamin D receptor activators represent a new therapeutic armamentarium to improve quality of life and reduce mortality in CKD.

E2F-1, Skp2 and cyclin E oncoproteins are upregulated and directly correlated in high-grade neuroendocrine lung tumors.

The transcription factor E2F-1 plays a crucial role in the control of cellular growth. We previously reported its differential pattern of expression in human lung tumors. In this study, we have investigated the relationships linking the status of E2F-1 and a mediator of its proteasomal degradation, the S-phase kinase-associated protein 2 (Skp2) F-box protein. Using immunohistochemistry in a series of 129 lung tumors of all histological types, we demonstrate that Skp2 accumulates preferentially in high-grade neuroendocrine (HGNE) lung carcinomas (86%, P<0.0001), and show that Skp2 overexpression is associated with advanced stages (P<0.0001) and nodal metastasis (P<0.0001) in neuroendocrine (NE) lung tumors. Unexpectedly, we observe that Skp2 and E2F-1 expression directly correlates in NE lung tumors (P<0.0001). Moreover, using cellular models, we identify Skp2 as a new E2F-1 transcriptional target. Furthermore, we also provide evidence that Skp2 interacts physiologically with E2F-1 and stimulates its transcriptional activity toward the cyclin E promoter. Consistently, we demonstrate that cyclin E expression directly correlates with Skp2 (P<0.0001) and E2F-1 (P=0.0001) status in NE lung tumors. Overall, our data provide the first evidence of a direct and functional interconnection between the E2F-1, Skp2 and cyclin E oncoproteins in HGNE lung carcinomas.

Lung carcinomas with a basaloid pattern: a study of 90 cases focusing on their poor prognosis.

Lung carcinoma with a basaloid pattern (BC) is classified as either a basaloid variant of squamous cell carcinoma (SCC) or as variant of large cell carcinoma (LCC) depending on the presence of a squamous component. In a previous study of 37 cases, the present authors showed that BC presented with a shorter median and overall survival. In order to confirm its clinical significance in a larger series, 90 BC, including 46 basaloid variants of LCC and 44 basaloid variants of SCC, were compared with 1,328 other nonsmall cell lung carcinoma (NSCLC) with regard to clinical features and survival. The survival of basaloid variants of LCC and SCC was comparable. Median and overall survival were significantly lower for BC than for NSCLC in stage I-II patients, with a median survival of 29 and 49 months, respectively, and 5-yr survival rates of 27 and 44% for BC and NSCLC. When disease-specific survival was considered, BC had a shorter survival than both NSCLC and SCC. Basaloid pattern confers a poor prognosis in nonsmall cell lung carcinoma, especially in stage I-II patients, suggesting that lung carcinoma with a basaloid pattern is not only a variant of squamous cell carcinoma or large cell carcinoma, but is a unique entity with a significantly poor prognosis.

[Early diagnosis of bronchial carcinoma after head and neck cancer]. / Diagnostic précoce du cancer bronchique après cancer "tête et cou"

BACKGROUND: Patients with a previous history of cancer of the upper respiratory and digestive tracts (URDT) frequently develop a bronchial carcinoma (synchronous or metachronous) that may affect their survival. OBJECTIVE: To determine the prevalence of bronchial carcinoma at an early stage in a population of patients treated for cancer of the URDT. MATERIALS AND METHODS: This was a single centre prospective study (2002-2006). Patients in remission following treatment of cancers of the buccal cavity, pharynx (stages I -II) and larynx (stages I - III), were examined by a spiral CT scan and fibreoptic bronchoscopy (white light and autofluorescence), with biopsies, and cytology of the bronchial aspirate. RESULTS: 60 patients (55 men) were included. Two peripheral bronchial carcinomas were detected by scanning and two more (proximal) by endoscopy. All 4 bronchial tumours were squamous carcinomas (stage IA). Three patients had surgery, the fourth declined intervention. CONCLUSION: Our study confirms the high prevalence (6.7%) of bronchial carcinoma in patients with a past history of cancer of the URDT. It emphasises the complimentary roles of spiral scanning and bronchoscopy in early diagnosis. It is still too early to evaluate the impact of these investigations on the survival of the patients.

E2F1 induces apoptosis and sensitizes human lung adenocarcinoma cells to death-receptor-mediated apoptosis through specific downregulation of c-FLIP(short).

E2F1 is a transcription factor that plays a well-documented role during S phase progression and apoptosis. We had previously postulated that the low level of E2F1 in primary lung adenocarcinoma contributes to their carcinogenesis. Here, we show that E2F1 triggers apoptosis in various lung adenocarcinoma cell lines by a mechanism involving the specific downregulation of the cellular FLICE-inhibitory protein short, leading to caspase-8 activation at the death-inducing signaling complex. Importantly, we also provide evidence that E2F1 sensitizes tumor as well as primary cells to apoptosis mediated by FAS ligand or tumor necrosis factor-related apoptosis-inducing ligand, and enhances the cytotoxic effect of T lymphocytes against tumor cells. Finally, we describe the specific overexpression of c-FLIP(S) in human lung adenocarcinomas with low level of E2F1. Overall, our data identify E2F1 as a critical determinant of the cellular response to death-receptor-mediated apoptosis, and suggest that its downregulation contributes to the immune escape of lung adenocarcinoma tumor cells.

[Non-solid and part-solid pulmonary nodules on CT scanning]. / Nodules pulmonaires partiellement ou totalement en verre dépoli.

INTRODUCTION: The entities of non-solid and part-solid pulmonary nodules on CT scan have been recently described. STATE OF ART: Nonsolid and part-solid pulmonary nodules account for between 2.9 and 19% of all pulmonary nodules detected in high-risk patients included in CT screening series for lung cancer. Radio-pathological correlations have shown that the aetiology could be either benign (chronic pneumonia, atypical adenomatous hyperplasia, localized fibrosis) or malignant (broncholoalveolar cell carcinoma, adenocarcinoma, more rarely metastasis). Part-solid or non-solid nodules are more likely to be malignant than solid ones. The doubling time of non-solid nodules can be longer than part-solid ones and even longer than the doubling time of solid nodules. Patient prognosis is related to the proportion of the ground glass component. PERSPECTIVE: The management of these nodules requires prolonged surveillance of nodules less than 10mm in diameter and surgical excision of nodules greater than 10mm persisting on scans between 1 to 3 months after they have been discovered and anti-inflammatory and anti-infectious therapy has been administered. CONCLUSIONS: Nonsolid and part-solid pulmonary nodules found on CT scan warrant a specific diagnostic workup.

Primary chemotherapy to avoid mastectomy in tumors with diameters of three centimeters or more.

In 165 women with breast cancer who were candidates for mastectomy because the largest diameter of the tumor was 3 cm or more, we administered primary chemotherapy in the attempt to substitute conservative for mutilating surgery. We then systematically quantitated tumor reduction by clinical, radiologic, and histopathologic evaluations. Five consecutive groups of 33 patients received cyclophosphamide, methotrexate, and fluorouracil (CMF); fluorouracil, doxorubicin (Adriamycin), and cyclophosphamide (FAC); or fluorouracil, epirubicin, and cyclophosphamide (FEC). The regimens for the five groups were as follows: group 1, three cycles of CMF; group 2, four cycles of CMF; group 3, three cycles of FAC; group 4, four cycles of FAC; and group 5, three cycles of FEC. In response to primary chemotherapy, 157 of the 161 assessable patients showed measurable tumor shrinkage; progressive disease was documented in four. Tumor shrinkage to less than 3 cm was documented in 127 (81%) of the 157 women subjected to surgery, thus allowing a breast-saving procedure, rather than modified radical mastectomy, in these 127 women. Histopathologic complete remission was documented in seven patients. Tumor response was unrelated to age, menopausal status, DNA content (ploidy), [3H]thymidine-labeling index, drug combination used, or number of treatment cycles in excess of three. The degree of response was inversely proportional to the initial tumor size, and the frequency of response was greater in receptor-negative tumors. Severe vomiting and hair loss were less frequent with CMF than with anthracycline-containing regimens, and the frequency of severe leukopenia and thrombocytopenia was minimal. Our results challenge the classical indication for primary mastectomy by showing that use of full-dose primary chemotherapy, sequentially combined with conservative surgery and radiation, can offer an effective and safe alternative to women concerned about the preservation of body integrity.

Activation of myc gene family in human lung carcinomas and during heterotransplantation into nude mice.

myc gene family activation (c-myc, L-myc, and N-myc) was examined in 26 human lung carcinomas and in their corresponding xenografts in nude mice. Of the 16 neuroendocrine (NE) carcinomas studied, amplification was observed in 4 with a c-myc probe and in 1 with both L- and N-myc probes. Overexpression was found in 1 of 7 cases studied for c-myc mRNA, in 1 of 7 cases for N-myc, and in 2 of 7 cases for L-myc. Of the 10 non-small cell lung carcinomas studied, only c-myc was amplified in 1 case and overexpressed in 5 of 7 cases. These results suggest that L- and N-myc gene activation are restricted to NE carcinomas. Over-expression of the myc gene without amplification was detected in 36% of cases. During heterotransplantation, there was a 27% change in myc gene abnormality and a 57% increase in myc expression levels, mostly in NE carcinomas (5 of 7; 71%). In a total of 42 xenografted lung carcinomas studied, 45% amplification and 77% overexpression of one of the myc genes were detected with a high prevalence of L-myc overexpression in NE carcinomas (50%) and of c-myc overexpression in non-small cell lung carcinomas (66%). Finally, 19 of 26 (73%) tumors are growing in nude mice with no myc gene amplification and 43% with no myc mRNA overexpression. Thus myc gene activation is not strictly required for heterotransplantation but seems to be a favorable factor in the maintenance and progression of lung carcinomas in vivo.

The human p19ARF protein encoded by the beta transcript of the p16INK4a gene is frequently lost in small cell lung cancer.

The p16IN4/CDKN2/MTS1 gene encodes two structurally different proteins: a cyclin-dependent kinase inhibitor called p16INK4a, which regulates retinoblastoma protein-dependent G1 arrest, and a cell cycle inhibitor designated p19ARF, which arrests cell growth in G1-S and also in G2-M. Whereas inactivation of p16INK4a has been described as a frequent event in lung cancer, the current function of p19ARF is still poorly understood. We have examined the expression of the human p19ARF (hp19ARF) protein in a large series of lung cancers using immunohistochemistry and showed that the protein was more frequently lost in high-grade neuroendocrine (NE) lung tumors (large cell NE carcinoma and small cell lung carcinoma; 51 of 78, 65%) than it was in non-small cell lung cancer (25 of 101, 25%). No deleterious mutation was found in exons 1beta and 2 of hp19ARF in those NE tumors with negative immunoreactivity, and a beta transcript was detected in the majority of them. Concomitant absence of hp19ARF and retinoblastoma proteins was frequently detected in high-grade NE lung tumors, whereas no relationship could be found between the status of hp19ARF and p53 proteins in those tumors. These results are consistent with an alternative growth suppressor function for hp19ARF in NE lung cancer that is distinct from that of p16INK4a. Moreover, the frequent uncoupling between the beta transcript and the hp19ARF protein suggests a novel mechanism of inactivation at the translational level.

Analysis of the activation of the myc family oncogene and of its stability over time in xenografted human lung carcinomas.

In order to validate the use of the nude mouse as a model for studying lung cancers, 21 different lung cancers were xenografted onto nude mice and the tumoral DNA and RNA were analyzed for abnormality in the myc family genes (c-myc, L-myc, and N-myc). Six of 14 small cell lung cancers (SCLC) showed a 4-35-fold amplification for L-myc, 5 of 7 non-SCLC a 3-5-fold amplification for c-myc, and 1 of 14 SCLC an 80-fold amplification for N-myc. Of the 7 SCLC with amplified L- or N-myc oncogenes, 4 were of the small and large histological type, while only 5 of the 21 cases studied were of the small and large type. All xenografted tumors with amplification of one of the myc genes showed overexpression of the related mRNA. Overexpression without amplification of the myc genes was observed for 3 SCLC and 2 non-SCLC. These results indicate that the L-myc gene seems to be associated with the small and large phenotype in SCLC, whereas c-myc seems to be implicated in non-SCLC. Of the 21 lung cancers studied 14 were analyzed for myc family gene activation for serial passages into nude mice. No variation of DNA amplification was observed during long-term growth in nude mice for any of the myc oncogenes. Changes in the level of mRNA expression were observed only for c-myc; a beginning of expression in one SCLC and an increase in expression in one non-SCLC were noted in late passages when compared with early ones. The nude mouse is therefore a valuable model for the study of lung cancers "over a 4-year period at least."

Distinct pattern of E2F1 expression in human lung tumours: E2F1 is upregulated in small cell lung carcinoma.

The transcription factor E2F1 is a key component of cell cycle that acts to transactivate genes required for S phase entry. Thus, it plays an important role in cellular proliferation, oncogenesis and differentiation. In order to investigate its potential implication in human lung carcinogenesis, we studied E2F1 protein expression by Western blotting and immunohistochemistry in a series of 58 human lung tumours of all histological types. We showed that E2F1 product was overexpressed in 92% (24/26) of small cell lung carcinoma (SCLC) and in 50% (5/10) of large cell neuroendocrine carcinoma (LCNEC) whereas it was undetectable in 90% (10/11) of adenocarcinoma and 82% (9/11) of squamous carcinoma when compared to corresponding normal lung. No amplification was found but an increase in E2F1 mRNA expression was detected in 75% (18/24) of SCLC overexpressing E2F1 product. In these tumours and in contrast with NSCLC, upregulation of E2F1 product was associated with its nuclear accumulation and with overexpression of several of its target-genes. Moreover, E2F1 overexpression in NE lung tumours was significantly associated with a high KI67 index (P<0.0001) as well as a Bcl-2:Bax ratio >1 (P<0.001). Overall, these results demonstrate a distinct pattern of E2F1 expression in human lung tumours and suggest that its deregulation could be involved in the carcinogenesis of SCLC.

Mechanisms of p16INK4A inactivation in non small-cell lung cancers.

The cyclin-dependent kinase inhibitor p16 (p16INK4A/CDKN2/MTS1) is a potent inhibitor of the cyclin D-dependent phosphorylation of the retinoblastoma gene (Rb) product, the inactivation of which induces loss of Rb-dependent G1 arrest through inappropriate phosphorylation of the Rb protein. To analyse the role of p16INK4A as a tumor suppressor in the genesis of non small cell lung cancers (NSCLC) and correlate loss of p16INK4A protein expression to genetic or epigenetic mechanisms, we have performed a comprehensive study of p16 status in a series of 43 NSCLC. To this end, we have investigated p16INK4A protein expression with immunohistochemistry, deletions of the gene by FISH, and determined the methylation status of exon 1alpha using a PCR-based methylation assay. Finally, possible mutations were studied by SSCP and subsequent sequencing. Twenty one of the 43 (49%) NSCLC studied exhibited an absence of p16INK4A nuclear staining. Of these, three (14%) had frameshift or missense mutations, seven (33%) displayed methylation of exon 1alpha and 10 (48%) displayed homozygous deletions. In total, 95% of the tumors with p16INK4A negative staining carried one of these three alternative genetic or epigenetic alterations. Furthermore, a high degree of chromosome 9 polysomy was found (58%) in those tumors with p16INK4A inactivation. Taken together these results suggest that deregulation of the p16 gene locus is a frequently occurring event in NSCLC through distinct mechanisms including rare point mutations, promotor methylation and frequent homozygous deletions. Furthermore, our data show that immunohistochemistry is a rapid and an accurate technique for screening of p16INK4A gene inactivation events that result in loss of protein expression.

Human ARF binds E2F1 and inhibits its transcriptional activity.

The INK4a/ARF locus which is frequently inactivated in human tumours encodes two different tumour suppressive proteins, p16(INK4a) and ARF. p16(INK4a) is a major component of the RB pathway. ARF is part of an ARF-mdm2-p53 network that exerts a negative control on hyperproliferative signals emanating from oncogenic stimuli. Among these is the transcription factor E2F1, a final effector of the RB pathway, that induces ARF expression. Recent data suggest that ARF function is not restricted to the p53 pathway. However, ARF target(s) implicated in this p53-independent function remains to be identified. We show that ARF is able to inhibit the proliferation of human cell lines independently of their p53 status. In this context, we demonstrate that ARF interacts physically with E2F1 and inhibits its transcriptional activity. Moreover, we show that mdm2 is required for the modulation of E2F1 activity by ARF. Beside the well-known p53 and mdm2 partners, these results identify E2F1 as a new ARF target. Thus, ARF can be viewed as a dual-acting tumour suppressor protein in both the p53 and RB pathways, further emphasizing its role in tumour surveillance.

Primary chemotherapy in operable breast cancer: eight-year experience at the Milan Cancer Institute.

PURPOSE: Primary chemotherapy was administered to patients with tumors that measured > or = 2.5 cm in largest diameter to decrease the size of the primary tumor and allow for effective local and distant control while avoiding mastectomy. PATIENTS AND METHODS: Two prospective nonrandomized studies were performed that used different regimens of primary chemotherapy followed by breast-sparing surgery in the presence of objective tumor remission. Additional postoperative chemotherapy was given to women at high risk of disease relapse. The median follow-up duration was 65 months. RESULTS: A total of 536 assessable patients were enrolled, and the main characteristics were fairly comparable between the two trials. Following primary chemotherapy, 85% of patients could be subjected to breast-sparing surgery; in 14 patients (3%), surgical specimens failed to show any residual neoplastic cell. In the final multivariate analysis, the histologically assessed extent of axillary node involvement (P < .001), as well as degree of response to primary chemotherapy (P = .034), represented the significant variables able to influence 8-year relapse-free survival. In women subjected to a breast-conserving approach, the cumulative risk of local relapse as first event alone was 6.8% (95% confidence interval, 3.9% to 8.8%). CONCLUSION: Current findings indicate that primary chemotherapy can be safely administered in women with large tumors (>5.0 cm) and can allow breast-sparing surgery in a high fraction of patients (62%). However, to assess effectively the worthiness of this approach on long-term results, properlyconceived large randomized studies with newer and more effective drug regimens are warranted.

Cytotoxic chemotherapy induces cell differentiation in small-cell lung carcinoma.

Despite the high response rates resulting from chemotherapy, the majority of small-cell lung cancer (SCLC) patients relapse with chemoresistant tumors. To analyze the phenotypic changes that are precursors of chemoresistant status, and to investigate the role of chemotherapy in these changes, tumor samples from 20 patients, taken before chemotherapy (etoposide, doxorubicin, and cyclophosphamide) and again at the onset of chemoresistance (after at least three courses of chemotherapy), were compared. The histologic changes were minor in 10 of 20 patients, as shown by an increase in cell size; they were major in 10 of 20 patients, with the appearance of mixed composite tumors in which neuroendocrine (NE), epidermoid, and glandular components were mixed. Major changes correlated with a good response to chemotherapy (P = .001). Ultrastructural studies showed an increase in neurosecretory granules and desmosomes, and a high frequency of multidirectional differentiation (45%) when comparison was made with pretherapy samples (10%) (P less than .01). Immunohistochemical (IH) analysis showed an increase in cytokeratin (CK) expression in treated patients, with a different labeling pattern and the expression of higher molecular weight CK. The expression of NE lineage markers (Leu 19, Sy 38, SL 11-14) remained stable, while that of NE differentiation markers (Leu 7, chromogranin) increased in the treated patients. The neuron-specific enolase (NSE) activity remained stable in treated SCLC. Large cells with a more differentiated phenotype and proliferative capacity (as shown by Ki 67 labeling), appeared to be characteristic of treated and secondary chemoresistant SCLC. The acquisition of a more complex phenotype, which correlates with primary response to therapy, implies a drug-induced differentiation in SCLC.

Promoter methylation of genes in bronchial lavages: a marker for early diagnosis of primary and relapsing non-small cell lung cancer?

A prospective screening program, including CT, autofluorescent bronchoscopy, biopsies and bronchial lavage (BL) collection, was initiated with the specific goal of identifying biomarkers for the early detection of non-small cell lung cancer. We report and discuss the results of p16, DAPK, MGMT, FHIT and APC methylation analysis in the 126 first patients: 77 at high risk of cancer and 49 followed up after primary cancer resection. Positive results were found in 49% of BLs, 53% in current smokers and 43% in former smokers. In presence of peripheral tumours, only 38% of BLs were abnormal versus 73% in presence of central tumours, 50% in presence of preneoplasic lesions and 47% in absence of lesions. FHIT methylation was an early event, observed in one-third of the BLs from patients with or without lesions as well as in tumours. APC methylation was a late event observed in 33% of tumours but rarely in BLs. p16 was methylated in 17% of BLs but in 48% of tumours; DAPK in 15% of BL and 22% of tumours. MGMT methylation was rare. Among patients followed up after cancer surgery, 14 were in remission with normalised BL, whereas three had positive BLs and relapsed with a central tumour. Thus, gene methylation in BL might help to detect central tumours but a CT is crucial for peripheral cancer detection.

Expression of plasminogen activator inhibitors 1 and 2 in lung cancer and their role in tumor progression.

The plasminogen activator cascade initiated by urokinase type plasminogen activator (u-PA) is involved in extracellular matrix degradation during the tumor invasion process. The plasminogen activator inhibitors 1 (PAI-1) and 2 (PAI-2) are two specific inhibitors of u-PA. We hypothesized that the balance between u-PA and its two inhibitors could be disrupted to favor plasminogen activation during lung cancer progression. Using immunohistochemistry, we analyzed the pattern of expression of u-PA, PAI-1, and PAI-2 in non-small cell lung carcinomas (NSCLC) and neuroendocrine (NE) lung tumors. u-PA and PAI-1 were both detected in stromal fibroblasts and in tumor cells. In 84 NSCLCs, their epithelial expression was strongly correlated and linked to the presence of node metastasis (P = 0.008), whereas their coexpression in fibroblasts was associated with larger tumor size (P = 0.04) and advanced stages (P = 0.009). In 72 NE tumors, u-PA and PAI-1 were more frequently expressed in fibroblasts in high-grade NE tumors (SCLC and large cell NE tumors) than in low- and intermediate-grade tumors (typical and atypical carcinoids). Comparison of in situ hybridization and immunohistochemistry in 14 cases showed that PAI-1 was consistently expressed by stromal fibroblasts, although the protein was also localized in tumor cells. In contrast, the expression of PAI-2 was restricted to fibroblasts and correlated with the absence of nodal involvement (P = 0.005). Considering NE tumors, the frequency of PAI-2 expression decreased along the NE spectrum from typical carcinoids to SCLCs. These data suggest that PAI-lacts in synergy with u-PA to favor tumor invasion process and connotes aggressivity, in contrast with PAI-2, which may block u-PA-mediated proteolysis and is inversely correlated with tumor progression.