The role of HER-2/neu expression on the survival of patients with lung cancer: a systematic review of the literature

Diagnostic surgical pathology in lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

OBJECTIVE

The objective of this study was to provide evidence-based background and recommendations for the development of American College of Chest Physicians guidelines for the diagnosis and management of lung cancer.

METHODS

A systematic search of the medical and scientific literature using MEDLINE, MDCONSULT, UpToDate, Cochrane Library, NCCN guidelines, and NCI/NIH search engines was performed for the years 1990 to 2006 to identify evidence-based and consensus guidelines. The search was limited to literature on humans and articles in the English language.

RESULTS

The pathologic assessment of lung cancers is based on a set of well-accepted findings, including histologic type, tumor size and location, involvement of visceral pleura, and extension to regional and distant lymph nodes and organs. Bronchial-based incipient neoplasia needs to be recognized both grossly and microscopically because these lesions may be multifocal and represent multistep carcinogenesis and may be amenable to therapy. Cytologic assessment of the individual with no symptoms is, as yet, of insufficient clinical benefit for screening of lung cancer. In challenging situations of pathologic differential diagnosis, additional studies may provide information that enables the separation of distinct tumor types. Pathobiological and molecular biological studies may yield prognostic and predictive information for clinical management and should be considered as part of protocol studies. Enhanced pathologic and molecular techniques may identify the presence of micrometastatic disease within lymph nodes; however, the clinical utility of these approaches is still unresolved. Intraoperative consultations have high diagnostic accuracy and may aid ongoing treatment and management decisions.

CONCLUSIONS

Pathologic assessment is a crucial component for the diagnosis, management, and prognosis of lung cancer. Selective diagnostic techniques and decision analysis will increase diagnostic accuracy. Cytologic screening, molecular characterization of tumors, and micrometastatic analysis are potential but not yet proved modalities for the evaluation of lung cancers.

Simultaneous expression of c-erbB-1, c-erbB-2, c-erbB-3 and c-erbB-4 receptors in non-small-cell lung carcinomas: correlation with clinical outcome

The expression of c-erbB receptors was immunohistochemically examined in paraffin embedded specimens from non-small-cell lung carcinomas. A total of 209 patients were enrolled [squamous-cell carcinomas (n=59), adenocarcinomas (n=130), large-cell carcinomas (n=15) and giant-cell carcinomas (n=5)]. The HercepTest kit scoring guidelines were used for the interpretation of positivity. C-erbB-1 was overexpressed in older patients, in squamous-cell carcinomas and in poorly-differentiated tumours, whereas c-erbB-2 overexpression with adenocarcinomas and poorly-differentiated tumours. C-erbB-4 overexpression correlated with advanced disease stage. The c-erbB-1/4 pair was the most commonly overexpressed and significantly correlated with female gender, while the c-erbB-1/2 pair with older age. Response to chemotherapy was significantly reduced in patients with tumours overexpressing c-erbB-1 receptor as well as the c-erbB-1/2 and c-erbB-3/4 receptor pairs. Patients' overall survival was significantly correlated with the co-expression of c-erbB-1 and c-erbB-4 receptors. These findings clearly suggest that specific receptors overexpression or co-overexpression is correlated with patients' disease control rate and outcome. A better understanding of the overexpression of the heterodimerized partners of c-erbB family receptors may provide a useful predictive indicator of response to molecular targeted therapies with c-erbB inhibitors.

Targeting receptor tyrosine kinase signalling in small cell lung cancer (SCLC): what have we learned so far?

Small cell lung cancer (SCLC) is an aggressive form of lung cancer, which represents 13% of all cases and is strongly associated with cigarette smoking. The survival of SCLC patients is dismal and has not greatly improved in the last 20 years, despite advances in chemotherapy regimens and a better understanding of SCLC biology. The development of resistance to chemotherapy and metastasis are commonly recognized as important causes of poor clinical outcome in SCLC. Targeting receptor tyrosine kinase (RTK) signalling represents an attractive approach to develop new drugs for SCLC, in view of the accumulating data demonstrating that polypeptide growth factors play a key role in driving SCLC cell proliferation, chemoresistance and metastasis. The insulin-like growth factor-I receptor (IGF-IR), c-Kit, vascular endothelial growth factor receptor (VEGFR) and epidermal growth factor receptor (EGFR) have been identified as potential drug targets in SCLC. Moreover, downstream signalling mediators of RTKs, such as phosphoinositide 3-kinase (PI3K)/Akt and the mammalian target of rapamycin (mTOR) may also represent attractive candidate molecules for anti-cancer therapies in SCLC. Here we will review the available data concerning results with RTK inhibitors in SCLC and the clinical trials undertaken to investigate the potential of these compounds as anti-tumour agents in SCLC.

Quality of reporting of cancer prognostic marker studies: association with reported prognostic effect

BACKGROUND

Issues of reported study quality have not been addressed empirically with large-scale data in the cancer prognostic literature.

METHODS

Eight quality measures pertaining to study design and assay methods (i.e., blinding, prospective versus retrospective design, power calculations, outcomes' definitions, time of enrollment, reporting of variables, assay description, and assay reference) were evaluated in cancer prognostic marker studies included in meta-analyses identified in Medline and EMBASE. To be eligible, meta-analyses had to include at least six studies and to examine binary outcomes. We estimated the ratios of relative risks, which compared the overall prognostic effects (summary relative risks) between poor-quality and good-quality studies for each quality item. Between-study heterogeneity was tested with the Q statistic (statistically significant at P<.10). All statistical tests were two-sided.

RESULTS

We identified 20 meta-analyses that included 331 cancer prognostic marker studies published between 1987 and 2005. Only three (0.9%) of the 331 studies presented power calculations, 129 (39.0%) studies stated that analyses were blinded, and 73 (21.5%) stated that they were prospective. Time of enrollment was defined in 232 (70.0%), 234 (70.7%) gave lists of candidate variables, and 254 (76.7%) defined outcomes. The assay used was described in 317 (95.8%), but only 177 (53.5%) provided the assay reference. Estimates of prognostic effects from poor-quality studies varied considerably and could be larger or smaller than summary estimates derived from meta-analyses. Summary ratios of relative risks of poor- versus good-quality studies for the seven quality measures ranged from 0.95 to but 1.26, but none was statistically significantly. There was statistically significant heterogeneity (P<.10) between the ratios of relative risk estimates across meta-analyses for blinding, defining endpoints, and stating variables and assay references.

CONCLUSIONS

Among cancer prognostic marker studies, reporting quality of design and assay information often appears suboptimal, indicating that this literature may be largely unreliable. Given the potential clinical importance of prognostic marker information, improved design and reporting of these studies are warranted.

A dimerization hierarchy in the transmembrane domains of the HER receptor family

Bitopic membrane proteins offer an opportunity for studying transmembrane domain interactions without the structural complexity inherent to multitopic integral membrane proteins. To date, only homomeric associations have been extensively studied quantitatively. Here we propose to assess the thermodynamics of heteromeric associations, which opens the way to investigating specificity and selectivity. A very interesting system of biological relevance with single transmembrane domains possibly involved in interactions with different partners is the EGFR receptor family. The four members, all tyrosine kinase receptors, are involved in an interaction network that potentially leads to a complete set of homo- and heterodimers, ideally suited to such a study. Furthermore, the transmembrane domains of these receptors have been previously implicated in their function in the past by mutations in the transmembrane domain leading to constitutive activation. We demonstrate, using a fluorescence-based measurement of interaction energies, a hierarchy of transmembrane domain interactions ranging from a noninteractive pair to strong dimerization. We propose a structural model based on the crystal structure of the EGFR dimer, to show how the dimeric structure favors these interactions. The correlation we observe between transmembrane domain and whole receptor interaction hierarchies opens a new perspective, suggesting a role for transmembrane receptor domains in the modulation of receptor signaling.

Expression of ontogene C-erbB-2 and its correlations with invasion and metastasis in colorectal carcinoma

AIM: To investigate the expression of oncogene C-erbB-2 and its significance in colorectal carcinoma.

METHODS: Immunohistochemical technique (SP) was performed to detect the expression of oncogene C-erbB-2 in 69 cases of colorectal carcinoma and its corresponding tissues from patients received curative resection.

RESULTS: The expression of C-erbB-2 was mainly found in cell membrane and cytoplasm of colorectal carcinoma tissues with a positive rate of 65.2% (45/69), which was significantly higher than that in the tissues of benign tumor (2/20, P < 0.05). The positive rate of C-erbB-2 expression had significant difference between colorectal cancer (65.2%) and its surrounding tissues (mesenteric: 47.8%, normal cancer-adjacent: 30.4%, distant resection margin: 13.0%; all P < 0.05). The expression of C-erbB-2 was significantly correlated with the gross morphology, differentiation of the tumor cells, clinical staging (Dukes staging) and lymph node metastasis (P < 0.05), but not with the age, sex of patients, tumor location and size, as well as distant metastasis (P > 0.05). The expression of oncogene C-erbB-2 in the mesenteric margin and cancer-adjacent tissues was markedly different between routine histology and immunohistochemistry (P < 0.05).

CONCLUSION: The expression of C-erbB-2 gene is positively correlated with tumor invasion and metastasis in colorectal carcinoma, and it is a marker in evaluating the prognosis of colorectal carcinoma.

The 17q12-q21 amplicon: Her2 and topoisomerase-IIalpha and their importance to the biology of solid tumours

Her2 and topoisomerase-IIalpha (T2A) gene amplification are separate events, although the latter is more frequently seen in Her2 amplified (34-90%) than in Her2 non-amplified (5-10%) tumours. There is a better correlation between Her2 amplification and protein overexpression in breast cancer (BC) than in other tumour types. This marker is also considered a powerful prognostic factor in BC, with similar data emerging in other solid tumours such as bladder, ovarian, endometrial, gastro-oesophageal and non-small cell lung cancer. Her2 amplification and/or overexpression are highly predictive of response to HER2-targeted compounds such as trastuzumab and lapatinib but have been inconsistent predictors of response to cytotoxic chemotherapy. There is also evidence that these tumours are relatively resistant to anti-oestrogen therapy (tamoxifen) but not to oestrogen deprivation (e.g. with aromatase inhibitors). T2A aberrations are uncommon events in solid tumours, with an overall prevalence of approximately 10%. T2A amplification has shown inconsistent correlation with T2A protein expression in preclinical and clinical studies, mainly because non-genetic events such as proliferation rate can also affect protein expression. Expression of T2A protein has not been shown to reliably predict response to T2A inhibitors, despite the fact that this enzyme is the direct target for these compounds. In BC, T2A amplification appears to be a good predictor of response to anthracyclines, but these data are still in the process of validation. The significance of T2A deletions is currently under investigation, but contrary to what was previously thought, it may also predict benefit from treatment with T2A inhibitors. The prognostic significance of T2A aberrations is currently unknown.

Expression of P53 and C-erbB-2 and their significances in chronic atrophic gastritis

AIM: To investigate the expression of P53 and C-erbB-2 proteins in chronic atrophic gastritis (CAG) and their correlation with clinicopathological parameters in CAG.

METHODS: SP immunohistochemistry was used to detect the expression of P53 and C-erbB-2 proteins in normal gastric mucosa (n = 56), chronic atrophic gastritis with cystic dysplasia (n = 61), intestinal metaplasia (n = 73), atypical hyperplasia (n= 295) and early gastric carcinoma (n = 57). The relationship between the expression of P53 and C-erbB-2 and the clinicopathological characteristics were analyzed.

RESULTS: The positive rates of P53 and C-erbB-2 protein expression were increased with the malignant degrees of gastric tissues. There were significant differences between normal gastric mucosa, moderate atypical hyperplasia, intestinal metaplasia, severe atypical hyperplasia and gastric carcinoma (P < 0.01). The expression of P53 was notably correlated with the age and gender of patients (χ² = 12.393, P < 0.01; χ² = 8.799, P < 0.01), while C-erbB-2 expression was just correlated with the age of patients (χ² = 7.706, P < 0.01). Besides, the expression of P53 was positively correlated with that of C-erbB-2 (r = 0.867, P < 0.05).

CONCLUSION: P53 and C-erbB-2 expression have significant correlations with the malignancy progression in CAG, and they can help to make early diagnosis for gastric cancer.

Thyroid transcription factor 1--a new prognostic factor in lung cancer: a meta-analysis

BACKGROUND

The aim of this study was to determine the prognostic role for survival of thyroid transcription factor 1 (TTF-1) in lung cancer.

METHODS

Studies evaluating survival and TTF-1 in lung cancer patients, published until August 2005, were assessed with a methodological scoring system. The required data for estimation of individual hazard ratios (HRs) for survival were extracted from the publications and a combined HR was calculated.

RESULTS

We identified 10 eligible papers, all dealing with non-small-cell lung cancer (NSCLC). Eight were meta-analysed (evaluable studies). Seven studies included patients with local and/or locoregional diseases and three dealt only with adenocarcinoma. Median methodological quality score was 65.9% (range = 31.8%-70.5%). TTF-1 positivity was associated with statistically significant reduced or improved survival in one and four studies, respectively. Combined HR for the eight evaluable studies was 0.64 [95% confidence interval (CI) = 0.41-1.00]. In the subgroup of adenocarcinoma, the combined HR was 0.53 (95% CI = 0.29-0.95).

CONCLUSION

TTF-1 is a good prognostic factor for survival in NSCLC. Its effect appears also significant when the analysis is restricted to patients with adenocarcinoma. This study supports the fact that TTF-1 could be included in further prospective trials studying prognostic factors in NSCLC.

Has Cox-2 a prognostic role in non-small-cell lung cancer? A systematic review of the literature with meta-analysis of the survival results

Cyclooxygenase-2 (COX-2) is overexpressed in lung cancer, especially in adenocarcinoma (ADC). Our aim was to determine the prognostic value of COX-2 on survival in patients with lung cancer. Studies evaluating the survival impact of COX-2 in lung cancer, published until December 2005, were selected. Data for estimation of individual hazard ratios (HR) for survival were extracted from the publications and combined in a pooled HR. Among 14 eligible papers, all dealing with non-small-cell lung cancer, 10 provided results for meta-analysis of survival data (evaluable studies). Cyclooxygenase-2 positivity was associated with reduced survival, improved survival or no statistically significant impact in six, one and seven studies, respectively. Combined HR for the 10 evaluable studies (1236 patients) was 1.39 (95% confidence intervals (CI): 0.97-1.99). In stage I lung cancer (six evaluable studies, 554 patients), it was 1.64 (95% CI: 1.21-2.24). No significant impact was shown in ADC. A slight detrimental effect on survival in patients with lung cancer is associated with COX-2 expression, but the statistical significance is not reached. This effect is statistically significant in stage I, suggesting that COX-2 expression could be useful at early stages to distinguish those with a worse prognosis.

Tyrosine kinase inhibitors. 19. 6-Alkynamides of 4-anilinoquinazolines and 4-anilinopyrido[3,4-d]pyrimidines as irreversible inhibitors of the erbB family of tyrosine kinase receptors

Structure-activity relationships for inhibition of erbB1, erbB2, and erbB4 were determined for a series of alkynamide analogues of quinazoline- and pyrido[3,4-d]pyrimidine-based compounds. The compounds were prepared by coupling the appropriate 6-aminoquinazolines or 6-aminopyrido[3,4-d]pyrimidines with alkynoic acids, using EDCI.HCl in pyridine. The compounds showed pan-erbB enzyme inhibition but were on average about 10-fold more potent against erbB1 than against erbB2 and erbB4. For cellular inhibition, the nature of the alkylating side chains was an important determinant, with 5-dialkylamino-2-pentynamide type Michael acceptors providing the highest potency. This is suggested to be due to an improved ability of the amine to participate in an autocatalysis of the Michael reaction with enzyme cysteine residues. Pyrido[3,4-d]pyrimidine analogue 39 was selected for in vivo evaluation and achieved tumor regressions at 10 mg/kg in the A431 human epidermoid carcinoma and at 40 mg/kg for the SF767 human glioblastoma and the SKOV3 human ovarian carcinoma. Complete stasis was observed at 40 mg/kg in the BXPC3 human pancreatic carcinoma as well as in the H125 human non-small-cell lung carcinoma.

Chemoprevention in lung carcinogenesis--an overview

Lung cancer ranks among the most commonly occurring malignancies and is currently the leading cause of cancer-related death worldwide. This is due to its late diagnosis and relative resistance to standard oncological treatment approaches. The heavy burden of lung cancer and its treatment resistance have elicited an intense interest in the promising approach of chemoprevention. Chemoprevention is defined as a pharmacologic intervention to suppress or reverse the carcinogenic process and the lung is one of the most studied sites for cancer chemoprevention. This review, with a short update on pulmonary carcinogenesis, will summarize the available knowledge of chemoprevention trials and agents with a preventive potential in the 'lung field'.

Molecular pathology of non-small-cell lung cancer

The molecular basis of lung carcinogenesis must be understood more fully and exploited to enhance survival rates of patients suffering from lung cancer. In this review we will discuss the major molecular alterations that occur in lung cancer. Emphasis is placed on alterations that occur early during carcinogenesis since they might be relevant for future screening programs. Finally we will shortly review new approaches that are used to study the molecular pathology of lung cancer and how they can be applied in a clinical setting.

Selective reporting biases in cancer prognostic factor studies

BACKGROUND

Nonreported and selectively reported information and the use of different definitions may introduce biases in the literature of prognostic factors. We probed these biases in a meta-analysis of a prognostic factor for head and neck squamous cell cancer (HNSCC) mortality that has drawn wide attention--the status of the tumor suppressor protein TP53.

METHODS

We compared results of meta-analyses that included published data plus unpublished data retrieved from investigators; published data; and only published data indexed with "survival" or "mortality" in MEDLINE/EMBASE, with or without standardized definitions. We also evaluated whether previously published meta-analyses on mortality predictors for various malignancies addressed issues of retrieval and standardized information. All statistical tests were two-sided.

RESULTS

For the 18 studies with 1364 patients that included published and indexed data, we obtained a highly statistically significant association between TP53 status and mortality. When we used the definitions preferred by each publication, the association was stronger (risk ratio [RR] = 1.38, 95% confidence interval [CI] = 1.13 to 1.67; P = .001) than when we standardized definitions (RR = 1.27, 95% CI = 1.06 to 1.53; P = .011). The addition of 13 studies with 1028 subjects that included published but not indexed data reduced the observed association (RR = 1.23, 95% CI = 1.03 to 1.47; P = .02). Finally, when we obtained data from investigators (11 studies with 996 patients) and analyzed it with all other data, statistical significance was lost (RR = 1.16, 95% CI = 0.99 to 1.35; P = .06). Among 18 published meta-analyses of 37 cancer prognostic factors, 13 (72%) did not use standardized definitions and 16 (89%) did not retrieve additional information.

CONCLUSIONS

Selective reporting may spuriously inflate the importance of postulated prognostic factors for various malignancies. We recommend that meta-analyses thereof should maximize retrieval of information and standardize definitions.

Is there a relationship between c-erbB-1 and c-erbB-2 amplification and protein overexpression in NSCLC?

In order to analyse the genetic abnormalities and protein expression of c-erbB-1 and -2, we have performed fluorescence in situ hybridisation (FISH) and immunohistochemistry (IHC) in resected non-small cell lung carcinoma (NSCLC). By IHC (106 patients), 11% of the patients were positive both for c-erbB-1 and -2 protein expression and 47% negative for both proteins. FISH (69 patients) showed a balanced disomy for both c-erbB-1 and -2 in 38%, all other cases had genetic abnormalities in at least one of both genes. c-erbB-2 gene was amplified in less than 10% of the tumours and c-erbB-1 gene was never amplified. c-erbB-2 protein overexpression was observed in only three out of the six cases showing c-erbB-2 amplification. The negative predictive value (NPV) of IHC for gene abnormalities was high for both markers. Median survival time (MST) was respectively of 76 and 174 weeks for patients with or without c-erbB-2 overexpression. Patients with c-erbB-2 amplification had a shorter survival: 125 weeks versus 165 weeks. MST was respectively of 109 and 196 weeks for patients with or without EGFR overexpression and patients with EGFR gene abnormalities had also a shorter survival with MST 136 weeks versus 189 weeks. These differences were not significant. In conclusion, if the majority of NSCLC showed genetic abnormalities in the c-erbB-1 and/or c-erbB-2 gene receptor, amplification could be observed only in a few tumours and was not strictly correlated with protein expression. Finally, survival of patients expressing EGFR and/or c-erbB-2 was slightly shorter.

Perspectives on novel therapies for bronchial carcinoma

Improvements in conventional cytotoxic treatment have probably reached a plateau for the treatment of lung cancer; therefore, new treatment strategies that are based on a better understanding of tumour biology are required. Some progress has been made for non-small cell lung cancer, in which erlotinib (Tarceva, OSI-774; Genentech), an epidermal growth factor receptor antagonist, has demonstrated a significant clinical benefit in a Phase III randomised trial, and has been licensed for second- or third-line treatment. Other therapies under investigation include angiogenesis inhibitors, COX-2 inhibitors, retinoids, farnesyl transferase inhibitors, Bcl-2 inhibitors and c-Kit antagonists. In this article the recent and ongoing Phase II and III trials of these therapies in lung cancer are summarised, and the prospects for their further clinical development are discussed.

Therapeutic targeting of receptor tyrosine kinases in lung cancer

Lung cancer is a difficult illness with a poor overall survival. Even though combination strategies with chemotherapy, radiation therapy and surgery have all been utilised, the overall outcome for this disease continues to be relatively disappointing. In order to make a difference in the treatment of lung cancer, novel therapeutics will have to be developed. Through basic biological studies, a number of receptor tyrosine kinases have been implicated in the pathogenesis and progression of lung cancer. In this review, the authors summarise the mechanisms of several major receptor tyrosine kinases in lung cancer, especially epidermal growth factor receptor, Her2/neu, MET, vascular endothelial growth factor and KIT. The biology associated with these receptors is described, and the various novel therapeutic inhibitory strategies that are ongoing in preclinical and clinical studies for lung cancer are detailed. Through understanding of receptor tyrosine kinases and the utilisation of specific inhibitors, it is hopeful that a dramatic impact will be made on the biology and therapy for lung cancer.

Association of HER-2 overexpression with prognosis in nonsmall cell lung carcinoma: a metaanalysis

BACKGROUND

Prognostic implications of overexpression of the HER-2 gene in nonsmall cell lung carcinoma (NSCLC) are a matter of controversy. Many conflicting results have been reported from different laboratories.

METHODS

A metaanalysis of published studies was performed for this quantitative review of the effects of HER-2 overexpression on survival among patients with NSCLC. Of 44 articles initially selected, 20 articles fulfilled eligibility criteria. DerSimonian-Laird random effects analysis was used to estimate the effects of HER-2 overexpression on survival differences (the survival rate among patients without HER-2 overexpression minus the survival rate among patients with HER-2 overexpression) at endpoints of 1 years, 3 years, and 5 years after resection of NSCLC.

RESULTS

In total, 2579 patients were included in the final analysis. Overall, HER-2 positivity differed according to histologic type and included 38% of patients with adenocarcinoma, 16% of patients with squamous cell carcinoma, and 18% of patients with large cell carcinoma (P < 0.0001). The combined survival differences in patients with NSCLC at 1 year, 3 years, and 5 years, respectively, were 2.7% (95% confidence interval [95% CI], 1.3-6.7%; P = 0.1787), 15.2% (95% CI, 5.8-24.5%; P = 0.0015), and 16.4% (95% CI, 7.9-14.8%; P = 0.0001), suggesting significant poorer survival at 3 years and 5 years among patients with HER-2 overexpression. In patients with adenocarcinoma, the combined survival difference at 5 years was 26.0% (95% CI, 16.0-36.1%; P < 0.0001), suggesting a particularly strong survival impact for HER-2 overexpression.

CONCLUSIONS

A significant, unfavorable prognostic effect of HER-2 overexpression in NSCLC was evident from the metaanalysis. However, because several studies that found no significant difference were excluded by the current eligibility criteria, caution is needed in interpreting the results.

Cytoplasmic expression of c-erbB2 in non-small cell lung cancers

The aim of this study was to investigate the expression of c-erbB2 in non-small cell lung cancers (NSCLCs) with attention both to membranous and cytoplasmic reaction, and to try to elucidate the meaning of cytoplasmic expression of c-erbB2 in NSCLCs. Immunohistochemical c-erbB2 expression and related clinico-pathological features were examined in 312 surgically resected patient tissues of NSCLCs, including 175 cases of adenocarcinoma and 137 cases of squamous cell carcinoma. Immunostaining of inner- and ecto-domain of c-erbB2, mRNA expression and the quantitation of soluble c-erbB2 in cultured media were performed in five NSCLC cell lines. Cytoplasmic expression of c-erbB2 was observed more frequently than membranous, both in patient tissues and cell lines. Neither membranous nor cytoplasmic expression of c-erbB2 was significantly correlated with short outcome in NSCLCs. Membranous c-erbB2 was expressed by both inner and ecto-domain, while cytoplasmic c-erbB2 was expressed by either or both inner and ecto-domain. c-erbB2 mRNA was produced in most cell lines; however, the soluble form was only detectable in a cell line that only presented a membranous c-erbB2. In conclusion, cytoplasmic c-erbB2 of NSCLCs was not a full-length protein only expressed in cellular membrane, but reflected degenerated c-erbB2 fragments with less functional ability.

The role of RAS oncogene in survival of patients with lung cancer: a systematic review of the literature with meta-analysis

The proto-oncogene RAS, coding for a 21 kDa protein (p21), is mutated in 20% of lung cancer. However, the literature remains controversial on its prognostic significance for survival in lung cancer. We performed a systematic review of the literature with meta-analysis to assess its possible prognostic value on survival. Published studies on lung cancer assessing prognostic value of RAS mutation or p21 overexpression on survival were identified by an electronic search. After a methodological assessment, we estimated individual hazard ratios (HR) estimating RAS protein alteration or RAS mutation effect on survival and combined them using meta-analytic methods. In total, 53 studies were found eligible, with 10 concerning the same cohorts of patients. Among the 43 remaining studies, the revelation method was immunohistochemistry (IHC) in nine and polymerase chain reaction (PCR) in 34. Results in terms of survival were significantly pejorative, significantly favourable, not significant and not conclusive in 9, 1, 31, 2, respectively. In total, 29 studies were evaluable for meta-analysis but we aggregated only the 28 dealing with non-small-cell lung cancer (NSCLC) and not the only one dealing with small-cell-lung cancer (SCLC). The quality scores were not statistically significantly different between studies with or without significant results in terms of survival, allowing us to perform a quantitative aggregation. The combined HR was 1.35 (95% CI: 1.16–1.56), showing a worse survival for NSCLC with KRAS2 mutations or p21 overexpression and, particularly, in adenocarcinomas (ADC) (HR 1.59; 95% CI 1.26–2.02) and in studies using PCR (HR 1.40; 95% CI 1.18–1.65) but not in studies using IHC (HR 1.08; 95% CI 0.86–1.34). RAS appears to be a pejorative prognostic factor in terms of survival in NSCLC globally, in ADC and when it is studied by PCR.

Epidermal growth factor receptor, HER-2/neu and related pathways in lung adenocarcinomas with bronchioloalveolar features

Lung adenocarcinomas with bronchioalveolar features (ABAF), formerly called bronchioloalveolar cancers (BAC), constitute a distinct clinical, radiological and pathological entity among lung malignancies. Epidermal growth factor receptor (EGFR) and to a less extent, HER-2/neu, are known to be overexpressed in non-small lung cancers, but their exact status in ABAF is not well-documented. Stimulation of these two receptors results in the initiation of two major cascades, namely phosphatidylinositol 3-kinase (PI-3K) and Ras-dependent pathways. We have therefore studied the expressions of EGFR, HER-2/neu as well as phosphorylated AKT (pAKT) and phosphorylated extracellular-signal regulated kinase (ERK), which are key molecules in these two pathways, in 15 ABAF patients. EGFR was found to be overexpressed in 9 of 15 patients (60%). HER-2/neu overexpression was detected in 6 of the 14 tumors tested (43%). pAKT and pERK were both found to be positive in 13 of 15 patients (87%). Six of the seven tumors with mucinous pattern were negative for EGFR, while all of the other eight cases were positive (P=0.001). Mucinous tumors were also less likely than non-mucinous tumors to overexpress HER-2/neu (17% versus 63%, respectively). These findings suggest that ABAF, particularly those with non-mucinous histology, commonly harbors EGFR and HER-2/neu overexpression. PI-3K and Ras-dependant pathways that lie downstream are generally activated, even in the absence of EGFR and/or HER-2/neu overexpression. ABAF may be a particularly promising candidate for EGFR-targeted strategies and this possibility merits extensive evaluation in clinical trials.

Ki-67 expression and patients survival in lung cancer: systematic review of the literature with meta-analysis

Among new biological markers that could become useful prognostic factors for lung carcinoma, Ki-67 is a nuclear protein involved in cell proliferation regulation. Some studies have suggested an association between Ki-67 and poor survival in lung cancer patients. In order to clarify this point, we have performed a systematic review of the literature, using the methodology already described by our Group, the European Lung Cancer Working Party. In total, 37 studies, including 3983 patients, were found to be eligible. In total, 49% of the patients were considered as having a tumour positive for the expression of Ki-67 according to the authors cutoff. In all, 29 of the studies dealt with non-small-cell lung carcinoma (NSCLC), one with small-cell carcinoma (SCLC), two with carcinoid tumours and five with any histology. In terms of survival results, Ki-67 was a bad prognosis factor for survival in 15 studies while it was not in 22. As there was no statistical difference in quality scores between the significant and nonsignificant studies evaluable for the meta-analysis, we were allowed to aggregate the survival results. The combined hazard ratio for NSCLC, calculated using a random-effects model was 1.56 (95% CI: 1.30–1.87), showing a worse survival when Ki-67 expression is increased. In conclusion, our meta-analysis shows that the expression of Ki-67 is a factor of poor prognosis for survival in NSCLC.

Validation of molecular and immunological factors with predictive importance in lung cancer

Histological classification and staging are cornerstones of diagnosis in lung cancer. Treatment options have been enriched in the last few years by the development of a number of new drugs, and therapy is now increasingly being carried out within multimodal concepts and at earlier stages. Still, outcome of the disease is far from satisfactory and progress in clinical and preclinical research is time-consuming. With the whole variety of potent new therapeutic compounds including classical cytostatics and biological factors at hand, many now believe that a clear improvement of treatment results will be derived from a better understanding of the biology of these tumours and a resulting improvement of diagnosis. Biological factors reflecting the underlying tumour biology and aspects of clinically important pathomechanisms may not only better predict outcome of the disease but also of its treatment, serving as surrogate markers for a more appropriate general intensification of therapy and ideally for specific "targeted" interventions. This article describes the different insights in the biology of these tumours in relation with the representing surrogate markers, and opens routes to possible diagnostic and therapeutic consequences.

Prognostic significance of HER2/neu, p53, and vascular endothelial growth factor expression in early stage conventional adenocarcinoma and bronchioloalveolar carcinoma of the lung

In this study, we investigated the prognostic value of HER2/neu, p53, and vascular endothelial growth factor in early stage conventional adenocarcinoma and bronchioloalveolar carcinoma of the lung. We studied 100 patients and consisted of 50 cases with conventional adenocarcinoma and 50 cases with bronchioloalveolar carcinoma (32 nonmucinous and 18 mucinous subtypes). Representative sections were immunostained for HER2/neu, p53, and vascular endothelial growth factor. Positivity was scored quantitatively by three observers and correlated with multiple prognostic parameters including survival. In the conventional adenocarcinoma, HER2/neu, p53, and vascular endothelial growth factor were expressed in 19/50 (38%), 32/50 (64%), 33/50 (66%), respectively. In this group, p53 showed a significant correlation with recurrence while vascular endothelial growth factor correlated with angiolymphatic invasion (P < 0.05). HER2/neu, p53, and vascular endothelial growth factor expression was associated with significantly shorter survival (log rank, P < 0.05). Patient whose tumors coexpressed both p53 and HER2/neu had the worst outcome. In the bronchioloalveolar carcinoma, HER2/neu, p53, and vascular endothelial growth factor were expressed in 9/50 (18%), 3/50 (6%) and 12/50 (24%), respectively which was significantly less than in conventional adenocarcinoma (P < 0.05). HER2/neu positivity showed a significant correlation with shorter survival (log rank, P < 0.05) in nonmucinous type. In conclusion, vascular endothelial growth factor was associated with angiolymphatic invasion and poor prognosis in conventional adenocarcinoma. Also, in conventional adenocarcinoma, p53, and HER2/neu expression appeared to be poor prognostic markers, while in bronchioloalveolar carcinoma, only HER2/neu was associated with a poorer prognosis. This immunostaining pattern suggests that conventional adenocarcinoma has different molecular abnormalities than bronchioloalveolar carcinoma.

Trastuzumab plus docetaxel in HER2/neu-positive non-small-cell lung cancer: a California Cancer Consortium screening and phase II trial

HER2 is reported to be overexpressed in 20% of cases of non-small-cell lung cancer (NSCLC), principally adenocarcinoma. Trastuzumab is a monoclonal antibody against HER2 that, when combined with a taxane, improves survival compared with chemotherapy alone in advanced breast cancer. In view of these observations, we conducted a phase II HER2 screening and efficacy trial of trastuzumab plus weekly docetaxel in cases of advanced NSCLC in which primary platinum-based therapy had failed. Patients with advanced or metastatic NSCLC were screened for HER2 overexpression by immunohistochemistry. Patients with HER2-positive tumors (2+ or 3+) were initially randomized to either single-agent trastuzumab or docetaxel. After completing 2 treatment cycles, all patients went on to receive the trastuzumab/docetaxel combination regardless of response to the single agents. Treatment consisted of docetaxel 30 mg/m2 weekly for 6 weeks followed by a 2-week break and trastuzumab 4 mg/kg intravenously on week 1 followed by 2 mg/kg per week thereafter. Cycle length was 8 weeks. Sixty-nine patients with NSCLC (33 men, 36 women) were screened between August 1999 and March 2001. Only 13 patients (19%) had HER2-positive disease; all 13 enrolled in the efficacy trial. Of 9 patients receiving docetaxel alone, 1 partial response (PR) was seen. None responded to trastuzumab alone. The overall outcomes to the sequence of single-agent therapy followed by combination therapy included a PR rate in 8% of cases, stable disease in 23%, progression in 46%, and nonassessable disease in 23%. Estimated event-free and overall survival times were 4.3 and 5.7 months, respectively. Treatment was well tolerated. The screening component of this trial demonstrated that the target population for trastuzumab therapy in NSCLC is relatively small. Because of the limited clinical activity of trastuzumab-based therapy in this cohort and the similar disappointing reports from other studies of trastuzumab in NSCLC, this trial was closed to further accrual. In view of the limited target population for HER2 inhibition, future efforts and resources should be directed toward molecular targets other than HER2 in NSCLC.

Lack of prognostic implications of HER-2/neu abnormalities in 345 stage I nonsmall cell carcinomas (NSCLC) and 207 stage I-III neuroendocrine tumours (NET) of the lung

HER-2/neu oncogene activation by either gene amplification and/or protein overexpression has been documented in several human malignancies. Irrespective of protein overexpression, HER-2/neu gene amplification is rare in lung cancer and studies on its prevalence and clinicopathological implications in early stage non-small cell lung cancer (NCSLC) and neuroendocrine tumours (NET) of the lung are lacking. We evaluated HER-2/neu abnormalities in 345 Stage I NSCLC and 207 Stage I-III NET of the lung of all the diverse histological types, by using immunohistochemistry and fluorescent in situ hybridization in selected cases. Overall, HER-2/neu immunoreactivity was detected in 23% of 345 NSCLC and in 7% of 207 NET. Gene amplification was seen in only 7 (7.4%) of the immunoreactive tumours, with high-level amplification (HER-2/neu gene to chromosome 17 ratio > 4.0) in 3 adenocarcinomas, 1 squamous-cell carcinoma and 1 large-cell neuroendocrine carcinoma (LCNEC), and low-level amplification (HER-2/neu gene to chromosome 17 ratio from 2.0 to 4.0) in 1 squamous-cell carcinoma and 1 LCNEC. None of tested carcinoids and SCLC showed gene amplification. All but 1 gene amplified case exhibited 2+ or 3+ membrane labeling. No relationship was found between gene amplification or protein overexpression and patients' survival or other clinicopathological variables. HER-2/neu gene amplification and protein overexpression are not closely correlated in lung carcinomas and do not bear any prognostic implication. Among neuroendocrine tumours, LCNEC show a slightly higher prevalence of either HER-2/neu gene amplification or protein overexpression.