Overexpression of the c-erbB-2/neu–encoded p185 protein in primary lung cancer

NSCLC and HER2: between lights and shadows

The therapeutic landscape of non-small-cell lung cancer (NSCLC) has dramatically changed in the last few years with the introduction of molecularly targeted agents, leading to unprecedented results in lung tumors with a paradigmatic shift from a "one size fits all" approach to an histologic and molecular-based approach. The discovery of epidermal growth factor receptor (EGFR) mutations in NSCLC in 2004 and the marked response to the EGFR tyrosine kinase inhibitor gefitinib, in a small subset of patients harboring these genetic abnormalities, stimulated the study of other kinase mutants involvement in NSCLC. The incredible story of ALK rearranged tumors, with the rapid Food and Drug Administration approval of Crizotinib after only 4 years from the discovery of EML4-ALK translocation in NSCLC, has profoundly influenced the concept of drug development in NSCLC, paving the way to a novel series of molecularly selected studies with specific inhibitors. The identification of these oncogenic drivers has dramatically changed the genetic landscape of NSCLC moving away from the old concept of a large indistinct histological entity to a combination of rare clinically relevant molecular subsets. Recently, a renewed interest has been emerging on the human epidermal growth factor-2 (HER2) pathway. Genetic aberrations of this signaling pathway have been reported over time to be associated in NSCLC with different sensitivity to the EGFR tyrosine kinase inhibitors, to have a possible prognostic role and more recently HER2 amplification has been emerged as a possible mechanism in EGFR-mutated tumors of acquired resistance to the EGFR tyrosine kinase inhibitors. In addition, dysregulation of the HER2 pathway, in particular HER2 mutations (mostly, in-frame exon 20 insertions), may represent a possible novel therapeutic target in NSCLC, paving the way for a new generation of targeted agents in NSCLC. Since anecdotal case reports of clinical activity of anti-HER2 agents in NSCLC patients with HER2 mutations, several targeted agents have been evaluated in HER2-mutated patients, generating a growing interest upon this oncogenic driver, leading to the design of molecularly selected trials with anti-HER2 compounds and the rediscover of hastily thrown out drugs, such as neratinib. The aim of this article is to provide an overview of the role of HER2 dysregulation in NSCLCs, trying to throw a light not only on the strengths but also the weaknesses of the studies conducted so far. It is a long way to the clinical implementation of these biomarkers and probably the increasing use of next generation sequencing techniques, the creation of large multi-institutional molecular testing platforms and the design of rationally based trials can get closer personalized medicine in NSCLC.

The interrelationship between HER2 and CASP3/8 with apoptosis in different cancer cell lines

HER2/ErbB2, a known proto-oncogene (also known as HER2, neu), is among the most practiced molecules in the cancer area. Human epidermal growth factor receptor 2 (HER2) is over expressed in approximately 20-30 % of breast cancer tumors and also in a lot of other human cancer types. It is known to be related to the aggressiveness of the disease, increased mortality and higher relapse ratio. The unusual HER2 overexpression is associated with more severe disease characteristics in several cancers. In recent past, there have been remarkable advances in understanding the role of the HER2 gene in cancers. Caspases are well renowned proteases that act as essential initiators and executioners of the apoptotic process. The primary function of HER2 is suppressing apoptosis to enhance cell survival and eventually giving rise to uncontrolled proliferation and tumor growth. The objective of this work was to study the expression levels of HER2 and apoptosis related factors CASP-3 and CASP-8 in several breast and other cancer cell lines and finally to find a meaningful correlation between all these. We summed up by obtaining an increase in expression of HER2 in all cancer cell lines as compared to that of CASP-3 and CASP-8. In summary we conclude that HER2 promotes cell survival by inhibiting apoptosis i.e. by downregulating CASP-3 and CASP-8. This is a novel study comprising the expression study of HER2 and different caspases in different cancer cell lines simultaneously. It is thus expected that this study will aid in better establishment of correlation between HER2 and caspases in different malignancies.

Relationship of immunohistochemical biomarker expression and lymph node involvement in patients undergoing surgical treatment of NSCLC with long-term follow-up

We try to identify the relationship between immunohistochemical marker expression and lymph node involvement in a cohort of 282 patients followed for 5 years after curative resection for NSCLC. In 189 patients (67%), lymph nodes were unaffected while 93 patients (33%) showed nodal involvement. The expression of 15 molecular markers was determined from each patient by tissue-array immunohistochemistry. Univariate analysis indicated significantly higher expression of E-cadherin, γ-catenin, p27, and p53 in patients with lymph node involvement. In those with unaffected nodes, p16 and Rb were expressed. E-cadherin expression was related to a 50% mortality reduction in patients with node involvement (hazard ratio (HR) 0.5; p = 0.017). c-erbB-2 expression was correlated with a 3.4-fold increase in mortality compared to patients without expression of this marker in subjects without node involvement (HR 3.41; p = 0.017). Multivariate analysis identified c-erbB-2 (HR 2.22; p = 0.089) and p27 (HR 1.44; p = 0.019) as prognostics of mortality while Rb (HR 0.74) indicated a good prognosis. The expression of proteins encoded by oncogenes and tumor suppressor genes was different according to lymph node involvement. The increased mortality related to c-erbB-2 expression in patients with unaffected lymph nodes would suggests a need for adjuvant treatment.

Soluble Human Epidermal Growth Factor Receptor 2 (sHER2) as a Potential Risk Assessment, Screening, and Diagnostic Biomarker of Lung Adenocarcinoma

Lung cancer is the leading cause of cancer-related death in the United States. Here, we evaluated the potential clinical utility of soluble human epidermal growth factor receptor 2 (sHER2) for the risk assessment, screening, and diagnosis of non-small cell lung cancer (NSCLC) using an unmatched case-control study design. Serum sHER2 concentrations were measured by immunoassay in 244 primary NSCLC cases and 218 healthy controls. Wilcoxon rank-sum tests, logistic regression models, and receiver operating characteristic plots were used to assess whether sHER2 is associated with lung cancer. Median serum sHER2 concentrations are higher in patients with adenocarcinoma than squamous cell carcinoma regardless of gender, and sHER2 is a weak, independent biomarker of adenocarcinoma, but not of squamous cell carcinoma, adjusted for age and gender. The age-adjusted relative risk (odds) of adenocarcinoma is 3.95 (95% CI: 1.22, 12.81) and 7.93 (95% CI: 2.26, 27.82) greater for women and men with high sHER2 concentrations (≥6.60 ng/mL) vs. low sHER2 concentrations (≤1.85 ng/mL), respectively. When adjusted for each other, sHER2, age, and gender discern healthy controls from patients with primary adenocarcinomas of the lung with 85.9% accuracy. We conclude that even though serum sHER2 is not a strong, stand-alone discriminatory biomarker of adenocarcinoma, sHER2 may be a useful, independent covariate in multivariate risk assessment, screening, and diagnostic models of lung cancer.

Genetic and epigenetic changes in lung carcinoma and their clinical implications

Lung cancer is the leading cause of cancer deaths worldwide. Recent advance in targeted therapy for lung cancer patients with epidermal growth factor receptor (EGFR) mutations has demonstrated a promising development toward personalized therapy for lung cancer patients. The development of lung cancer is a complex process, involving a series of genetic and epigenetic changes. Tobacco smoke is the predominant etiologic risk factor for lung cancer. However, some lung cancers, especially adenocarcinomas, arise in patients who have never smoked, suggesting the importance of host genetic/epigenetic susceptibility in the occurrence and development of lung cancer. Understanding of these genetic and epigenetic changes will further aid in the biomarker-driven personalized therapy for lung cancer patients. In this review, we summarize the genetic and epigenetic alterations observed in lung cancers, including chromosomal loss of heterozygosity, tumor-suppressor gene mutation, gene methylation, histone modification, and microRNA expression changes. Clinical and preclinical studies have implied specific genetic/epigenetic changes for clinical application in lung cancer patients. However, more efforts are required in validation of the identified molecular markers in lung cancer patients for early detections, assessment for treatment response, and survival predictions.

Women and lung cancer: clinical and molecular profiling as a determinate for treatment decisions: a literature review

In the past decade the incidence of lung cancer among women has risen, whereas among men it has slightly declined. Important differences in lung cancer have been demonstrated between men and women, although many areas still remain controversial. Some biologic differences may justify the increase in response of women to therapy for lung cancer and can partially explain the improved survival of women compared with men. We extensively reviewed the published scientific literature on this topic in order to investigate the clinical and genetic profiling underlying lung cancer in women and to use this information as a tool for medical therapy.

Somatic pharmacogenomics in cancer

Many of the initial examples of the clinical utility of pharmacogenetics were elucidated in the field of oncology. Those examples were largely based on the existence of germline genetic variation that influences the metabolism of cytotoxic drugs. However, with the development of kinase inhibitors, drugs designed to preferentially target altered proteins driving oncogenesis, pharmacogenetics in cancer has shifted to understanding the somatic differences that determine response to these targeted agents. It is becoming increasingly clear that understanding the molecular genetics of cancer will lead to the further development of targeted therapeutics. Therefore, it is imperative that pharmacogenomics researchers understand the motivations and challenges of developing targeted therapies to treat cancer as a paradigm for personalized medicine. However, much of the discussion in the pharmacogenomics community in cancer is still largely focused on the germline variants as predictors of drug toxicity. In light of that fact, this review presents a detailed discussion of the development of commonly used targeted therapies for the treatment of hematological and solid tumors, the somatic mutations that determine response to those therapies, and the mechanisms of drug resistance.

EGFR, ERBB2, and KRAS mutations in Korean non-small cell lung cancer patients

The epidermal growth factor receptor (EGFR), and its family members play an important role in the development and progression of lung cancers. It has been reported that somatic mutations in the tyrosine kinase domain of the EGFR or ERBB2 genes occur in a subset of patients with lung cancer. We searched for mutations of the EGFR, ERBB2, and KRAS genes in surgically resected non-small cell lung cancers (NSCLCs) to determine the prevalence of these mutations in Korean lung cancer patients. In addition, we examined the relationship between the mutations and clinicopathologic features of lung cancers. Mutations of the EGFR, ERBB2, and KRAS genes were determined by polymerase chain reaction-based direct sequencing in 115 surgically resected non-small cell lung cancers. EGFR mutations were present in 20 patients (17.4%). The EGFR mutations were found only in adenocarcinomas (20 of 55 adenocarcinomas, 36.4%). The ERBB2 mutation was found in 1 adenocarcinoma of the 115 NSCLCs (0.9% overall; 1.8% of the 55 adenocarcinomas). KRAS mutations were found in 6 (5.2%) of the 115 NSCLCs (2 of 60 squamous cell carcinomas, or 3.3%, and 4 of 55 adenocarcinomas, or 7.3%). EGFR mutations in adenocarcinomas were more frequent in women (P = 0.02) and in never-smokers (P = 0.004). EGFR mutations in adenocarcinomas were not associated with pathologic stage in never-smokers, but were more frequent in pathologic stage II-IV than in stage I in ever-smokers (P = 0.01). Of the 55 adenocarcinomas, 25 (45.5%) had mutations of one or another of the three genes; EGFR mutations were never found in adenocarcinomas together with ERBB2 or KRAS mutations. These findings suggest that the EGFR mutation is frequent in Korean lung cancer patients, and that the ERBB2 mutation is rare. Further studies are needed to investigate the role of EGFR mutations in the carcinogenesis of adenocarcinoma among smokers.

Sex Differences in the Predictive Power of the Molecular Prognostic Factor HER2/neu in Patients with Non–Small-Cell Lung Cancer

BACKGROUND

Recent studies imply that HER2/neu is a potential prognostic factor in patients with non-small-cell lung cancer (NSCLC). Whereas considerable evidence indicates sex differences in epidemiologic, hormonal, biologic, and genetic factors in this disease, it has remained unknown whether HER2/neu has a diverse function as a prognostic factor in men and women.

PATIENTS AND METHODS

We investigated the association between gene expression levels of HER2/neu in the primary tumors of 90 patients with curable resected NSCLC and survival, especially analyzing whether there is a different potential of this molecular factor in its prognostic impact between men and women.

RESULTS

High HER2/neu gene expression levels were found in 62 patients (68.9%), and low HER2/neu gene expression levels were found in 28 patients (31.1%). High HER2/neu messenger RNA expression levels were associated with inferior survival (P = 0.09) compared with lower HER2/neu expression. Survival analysis was then carried out separately for men and women in this group of patients. An HER2/neu gene expression cutoff point was identified that separated women, but not men, into good and poor prognostic groups.

CONCLUSION

These findings suggest that HER2/neu as a prognostic factor is strongly sex specific, indicating that it is not useful for men but highly predictive for women.

Randomized phase II study of weekly docetaxel plus trastuzumab versus weekly paclitaxel plus trastuzumab in patients with previously untreated advanced nonsmall cell lung carcinoma

BACKGROUND

Trastuzumab is a monoclonal antibody directed against the human epidermal growth factor receptor-2 (HER-2). Nonsmall cell lung carcinoma (NSCLC) overexpresses HER-2 protein in approximately 20% of cases. In the current study, the authors combined trastuzumab with weekly taxanes in an attempt to improve outcomes over standard chemotherapy in patients with advanced NSCLC.

METHODS

The primary objective was to determine whether docetaxel plus trastuzumab or paclitaxel plus trastuzumab was the superior regimen based on response and toxicity, and to determine whether either regimen was appropriate for further testing in a randomized Phase III trial. After stratification based on the results of HER-2 immunohistochemistry, chemotherapy-naive patients were randomized to receive trastuzumab plus docetaxel or trastuzumab plus paclitaxel. The study was designed so patients with or without HER-2 overexpression would be distributed equally between the study arms.

RESULTS

Immunohistochemistry for HER-2 protein expression was attempted for 182 pathologic samples from 169 patients. Twenty-eight of the 179 evaluable samples (16%) revealed 2+ or 3+ staining. The objective response rate was 23% (7 of 30 patients) in the patients treated with docetaxel plus trastuzumab and 32% (11 of 34 patients) in the patients treated with paclitaxel plus trastuzumab (P=0.76, Wilcoxon test). No difference was noted in the median survival (16 mos vs. 14 mos) or 1-year survival (57% vs. 55%) (P=0.998). Toxicities were mild in both treatment arms. No difference with regard to response rates or survival was noted between HER-2-positive (2+ or 3+) and HER-2-negative (0-1+) patients.

CONCLUSIONS

The expression of HER-2 protein in patients with advanced NSCLC in this study was found to be similar to that reported in previous series. The response rates and toxicities for patients treated with docetaxel and trasuzumab or paclitaxel and trasuzumab were not significantly different, though survival in both arms was better than expected. HER-2 expression status did not appear to affect outcomes for this uniform group of patients who were treated in a comparable fashion. Because of the infrequency of HER-2 overexpression, and the absence of improved outcomes in patients with NSCLC who were treated with trastuzumab plus chemotherapy in other studies, neither regimen tested will be advanced to a Phase III trial.

Combination Treatment with Erlotinib and Pertuzumab against Human Tumor Xenografts Is Superior to Monotherapy

In many solid tumors, overexpression of human epidermal growth factor receptors (e.g., HER1/EGFR and HER2) correlates with poor prognosis. Erlotinib (Tarceva) is a potent HER1/EGFR tyrosine kinase inhibitor. Pertuzumab (Omnitarg), a novel HER2-specific, recombinant, humanized monoclonal antibody, prevents heterodimerization of HER2 with other HERs. Both mechanisms disrupt signaling pathways, resulting in tumor growth inhibition. We evaluated whether inhibition of both mechanisms is superior to monotherapy in tumor cell lines expressing different HER levels. Human non-small cell lung cancer (NSCLC) cells (Calu-3: HER1/EGFR 0+, HER2 3+; QG56: HER1/EGFR 2-3+, HER2 0+) and breast cancer cells (KPL-4: HER1/EGFR 2-3+, HER2 3+) were implanted into BALB/c nu/nu mice and severe combined immunodeficient beige mice, respectively. Tumor-bearing mice (n = 12 or 15 per group) were treated with vehicle (Captisol or buffer), erlotinib (orally, 50 mg/kg/d), pertuzumab (i.p. 6 mg/kg/wk with a 2-fold loading dose), or erlotinib and pertuzumab for 20 (QG56), 27 (KPL-4), or 49 (Calu-3) days. Drug monotherapy had antitumor activity in all models. Tumor volume treatment-to-control ratios (TCR) with erlotinib were 0.36 (Calu-3), 0.79 (QG56), and 0.51 (KPL-4). Pertuzumab TCR values were 0.42, 0.51, and 0.64 in Calu-3, QG56, and KPL-4 models, respectively. Combination treatment resulted in additive (QG56: TCR 0.39; KPL-4: TCR 0.38) or greater than additive (Calu-3: TCR 0.12) antitumor activity. Serum tumor markers for NSCLC (Cyfra 21.1) and breast cancer (soluble HER2) were markedly inhibited by combination treatment (80-97% in Calu-3 and QG56; 92% in KPL-4), correlating with decreased tumor volume. Overall, erlotinib and pertuzumab are active against various human xenograft models, independently of HER1/EGFR or HER2 expression. A combination of these HER-targeted agents resulted in additive or greater than additive antitumor activity.

c-erbB-2 as a target for immunotherapy

The c-erbB-2 proto-oncogene encodes a 185 kDa transmembrane Type 1 tyrosine kinase receptor whose amplification and/or overexpression has been linked with poor prognosis in a variety of cancers. The oncoprotein has been suggested to play a key role in tumour cell invasion, motility and metastasis, and in responsiveness to therapeutic agents. Over-expression of c-erbB-2 therefore identifies an important subset of patients with a high probability of relapse, but low probability of response to certain conventional therapies. The cell surface location of the oncoprotein, its stability of expression and low levels in normal adult tissues render it an attractive target for immunotherapeutic intervention. Although a 'self' antigen, there is evidence that c-erbB-2 p185 can induce both humoral and cell-mediated immune responses in cancer patients. Approaches to exploit p185 as an immunotherapeutic target include vaccination with peptides, plasmid DNA or vectors (viruses/bacteria) carrying the gene; with cytokines, co-stimulatory factors and superantigens being evaluated as adjuvants. Many monoclonal antibody (mAb)-based strategies are also in clinical development. Monoclonal antibodies can serve multiple functions; direct inhibition of c-erbB-2 activity, recruitment of host effector mechanisms and direct or indirect delivery of toxic payloads. Clinical trials in patients with late stage disease have shown that many of these approaches are safe, feasible and relatively non-toxic, and, in some cases, objective responses have been seen. As with all immunotherapy, the greatest benefit is likely to be obtained in patients with minimal residual disease in an adjuvant setting; such studies are awaited with interest.

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.

HER2/neu expression and amplification in non-small cell lung cancer prior to and after neoadjuvant therapy

BACKGROUND

Expression and amplification of the HER2/neu protooncogene was analyzed in locally advanced NSCLC in a multimodality therapy approach in order to obtain information on the predictive value of HER2/neu for success or failure of neoadjuvant therapy.

METHODS

In the scope of a prospective randomized phase III-trial, tumor tissue of pre-therapeutically obtained mediastinal lymph node biopsies (n=105) and corresponding post-surgical resection specimens (n=44) was analyzed by means of immunohistochemistry (DAKO-Hercep-Test) and fluorescence in situ hybridization (FISH). In 58 of 105 patients with metastatic mediastinal lymph node disease the extent of therapy-induced tumor regression could be established.

RESULTS

Concerning HER2/neu expression, 16 lymph node biopsies (15.2%) showed 1+, 2+, or 3+ results. Five of these cases revealed amplification in FISH analysis (4.8%). In 44 corresponding resection specimens, Hercep-Test showed 1+, 2+, or 3+ results in 13 tumors (29.5%). Two of these patients revealed HER2/neu amplification in FISH analysis (4.5%). In patients with HER2/neu expressing tumors a trend towards a less extensive therapy-induced tumor regression could be demonstrated. When comparing pre-therapy and post-surgical results, there was a weak trend towards a selection of HER2/neu expressing tumor tissue in the course of neoadjuvant therapy.

CONCLUSIONS

Only a limited subcollective of locally advanced NSCLC meets the biological requirements for anti-HER2/neu therapy. HER2/neu positive tumors appeared to be relatively resistant to chemotherapy and radiation treatment, none of these cases having a pathological complete or at least subtotal response in the corresponding resection specimens. This observation requires confirmation in large randomized controlled studies.

Trastuzumab in combination with cisplatin and gemcitabine in patients with Her2-overexpressing, untreated, advanced non-small cell lung cancer: report of a phase II trial and findings regarding optimal identification of patients with Her2-overexpressing disease

The purpose of this study was to evaluate the feasibility, efficacy, safety, and pharmacokinetics of trastuzumab plus cisplatin and gemcitabine in patients with Her2-overexpressing stages IIIB or IV non-small cell lung cancer (NSCLC) and to study the relationship between results from the two methods for determining levels of Her2 overexpression. Chemonaive patients were eligible if they had stages IIIB or IV NSCLC with either a Her2 score of at least 1+ by immunohistochemical (IHC) analysis or a serum Her2 shed antigen level of at least 15 ng/ml by enzyme-linked immunosorbent assay (ELISA). Treatment consisted of cisplatin 75 mg/m(2) day one plus gemcitabine 1250 mg/m(2) days one and eight plus trastuzumab 4 mg/kg day one and 2 mg/kg weekly thereafter on a 21-day cycle for six cycles followed by weekly maintenance trastuzumab therapy. Of the 21 patients enrolled, 8 (38%) patients had a partial response. The 1-year survival rate was 62% (13/21). Median time to progression was 36 weeks. Pharmacokinetic studies revealed no interaction between trastuzumab and gemcitabine plus cisplatin. In patients screened for this study, Her2 expression was zero in 283/360 (79%); 1+ in 32/360 (9%); 2+ in 27/360 (8%); and 3+ in 18/360 patients (5%). Serum Her2 shed antigen was >15 ng/ml in 27/ 288 (9%) patients. Of patients who had both Her2 assays, 24% (4/17) with ELISA scores >15 ng/ml had IHC scores of 3+, compared with only 2% (3/145) of the patients <15 ng/ml and 4% (7/162) of all patients. The addition of trastuzumab to cisplatin and gemcitabine was well tolerated, but further study will be required to determine whether this combination is superior to chemotherapy alone. This may be demonstrated if only those patients with Her2, having a score of IHC 3+ were eligible. Since IHC 3+ is rare in NSCLC, performing IHC in only those patients with serum Her2 shed antigen >15 ng/ml would greatly increase the efficiency of IHC screening though at the cost of excluding nearly half the patients with Her2 scores of 3+ on IHC analysis. Thus, if sequential screening consisting of serum ELISA followed by IHC analysis is implemented, it may make a trastuzumab trial feasible but should ultimately be supplanted by another screening system if trastuzumab is shown to be beneficial to some patients with IHC Her2 scores of 3+.

Randomized phase II trial of gemcitabine-cisplatin with or without trastuzumab in HER2-positive non-small-cell lung cancer

BACKGROUND

Trastuzumab provides significant clinical benefits in HER2-positive metastatic breast cancer patients when administered in combination with chemotherapy. Chemotherapy has also been shown to be beneficial in some patients with advanced non-small-cell lung cancer (NSCLC). The present randomized phase II trial examined the effect of adding trastuzumab to a standard chemotherapeutic combination (gemcitabine-cisplatin) in patients with HER2-positive NSCLC.

PATIENTS AND METHODS

Patients with untreated stage IIIB/IV HER2-positive NSCLC received up to six 21-day cycles of gemcitabine 1250 mg/m(2) (days 1 and 8) and cisplatin 75 mg/m(2) (day 1). Patients in the trastuzumab arm received trastuzumab 4 mg/kg intravenously (i.v.) followed by 2 mg/kg/week i.v. until progression.

RESULTS

Of 619 patients screened, 103 were eligible. Fifty-one patients were treated with trastuzumab plus gemcitabine-cisplatin and 50 with gemcitabine-cisplatin alone. Efficacy was similar in the trastuzumab and control arms: response rate 36% versus 41%; median time to progression 6.3 versus 7.2 months; and median progression-free survival (PFS) 6.1 versus 7 months. Response rate (83%) and median PFS (8.5 months) appeared relatively good in the six trastuzumab-treated patients with HER2 3+ or fluorescence in situ hybridization (FISH)-positive NSCLC. Addition of trastuzumab to gemcitabine-cisplatin was well tolerated, side-effects were as expected, and trastuzumab did not exacerbate the known toxicity of gemcitabine and cisplatin. Symptomatic cardiotoxicity was observed in one trastuzumab-treated patient. Serum trastuzumab concentrations in the presence of gemcitabine-cisplatin were comparable to those of trastuzumab alone.

CONCLUSIONS

Trastuzumab plus gemcitabine-cisplatin is well tolerated. Clinical benefit was not observed. Although HER2 3+/FISH-positive patients may benefit from trastuzumab, the subgroup is too small to provide definitive information. No significant effect of gemcitabine-cisplatin on trastuzumab pharmacokinetics was observed.

Prognostic factors

The best predictive models of today can predict no more than 50% of the natural variability of the disease, despite the sophisticated mathematic analyses and the dozens of variables assessed. Clearly, a universe of still unknown prognostic factors remains to be discovered. Analogous to infinity being immeasurable, the fate of the individual patient will never be calculated mathematically. As the discovery of new prognostic factors continues, however, the prediction of the outcome of patients becomes more reliable. Although some prognostic factors (eg, tumor neoangiogenesis and quality of life) are already supported by a large body of evidence, recent research has introduced new groups of prognostic factors (eg, molecular genetic markers and the subclinical activation of coagulation fibrinolysis). Other intriguing factors (eg, a state of mental depression) might also be recognized as important in the near future. A new small portion of the universe has been explored.

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.

Epidermal growth factor family of receptors in preneoplasia and lung cancer: perspectives for targeted therapies

The Erb-B family of receptors plays an important role in lung carcinogenesis and tumor development, and EGFR and HER2 are highly expressed in bronchial preneoplasia. In invasive tumors, EGFR are expressed in 50-90%, and mostly in squamous cell carcinomas, but also in adenocarcinomas and large cell carcinomas, while HER2 is less frequently expressed (20-30%) and mostly expressed in adenocarcinomas. Bronchioloalveolar cell carcinomas may present a distinct EGFR profile compared to the other NSCLCs and evidence and consequences are discussed. The genetic mechanisms responsible for overexpression of EGFR and HER2 proteins might be numerous, including gene dosage (overrepresentation or amplification) as well as translational and post-translational mechanisms. However, for EGFR and HER2 there is a positive correlation between gene copy numbers and level of protein expression demonstrated by fluorescence in situ hybridization analysis and immunochemistry. Gene amplification for EGFR and HER2 is demonstrated in only 5-10% of the tumors. The treatment status and therapeutic limitation with trastuzumab (Herceptin) in lung cancer compared to breast cancer is discussed.

Inhibitors of epidermal-growth-factor receptors: a review of clinical research with a focus on non-small-cell lung cancer

Despite aggressive surgical and chemotherapeutic interventions, non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related death in men and women with overall cure rates of less than 15%. Recent advances in our understanding of cellular signalling and its critical role in tumorigenesis has led to the development of novel therapies which may offer new hope. In particular, the epidermal growth-factor receptor superfamily is an attractive therapeutic target because it is commonly overexpressed in malignant disease, regulates many vital cellular processes, and seems to be a negative prognostic indicator. Several selective inhibitors of this family of receptors are currently being evaluated in several cancers including NSCLC. In this review we examine current preclinical and clinical evidence on monoclonal antibodies (cetuximab, ABX-EGF, EMD72000, MAb ICR62, h-R3, MDX-447, MDX-H210, trastuzumab, and 2C4), immunoconjugates (Y10, Ua30:2, Mab806), anti-EGF vaccine (YMB2000), and tyrosine kinase inhibitors (gefitinib, erlotinib, CI1033, GW572016, EKB 569, PKI166, PD158780, and TAK 165).

ErbB-2 activates Stat3 alpha in a Src- and JAK2-dependent manner

Stats (signal transducer and activator of transcription) are latent transcription factors that translocate from the cytoplasm to the nucleus. Constitutive activation of Stat3 alpha by upstream oncoproteins and receptor tyrosine kinases has been found in many human tumors and tumor-derived cell lines. Constitutively activated Stat3 alpha is often correlated with the activation of ErbB-2, a member of the EGFR family. To explore the involvement of ErbB-2 in the activation of Stat3 and the mechanism underlying this event, an ErbB-2 point mutant was used as a model of constitutively activated receptor. Phenylalanine mutations (Y-->F) were made in the autophosphorylation sites of the receptor, and their ability to activate Stat3 alpha was evaluated. Our results suggest that Stat3 alpha and JAK2 associates with ErbB-2 prior to phosphorylation of the receptor and that full activation of Stat3 alpha by ErbB-2 requires the participation of other non-receptor tyrosine kinases. Both Src and Jak2 kinases contribute to the activation of Stat3 alpha but Src binds to ErbB-2 only when the receptor is phosphorylated. Our results also suggest that tyrosine 1139 may be important for Src homology 2 domain association because a mutant lacking this tyrosine reduces the ability of the Src homology 2 domain to bind to ErbB-2 and significantly decreases its ability to activate Stat3 alpha.

Protein expression profile of primary human squamous cell lung carcinomas indicative of the incidence of metastases

The purpose of this investigation was to evaluate firstly whether different protein expression patterns exist in primary squamous cell lung carcinomas of patients with and without lymph node involvement and secondly, whether or not different patterns exist in tumours with positive lymph nodes. For this reason, formalin-fixed, paraffin-embedded specimens from 130 patients with squamous cell lung carcinomas were analyzed by immunohistochemistry. In a first step, proteins were selected which showed a relationship to lymph node involvement. The expression of JUN, ERBB2, MYC, cyclin D, PCNA, bFGF, VEGF and Hsp70 proteins revealed a positive correlation to lymph node involvement. In contrast, caspase-3, Fas ligand, Fas/CD95, and PAI showed an inverse correlation to lymph node involvement. In a second step, these parameters were further analyzed by hierarchical cluster analyses. The resulting clusters were correlated to patients with or without lymph node involvement. The data show that different protein expression patterns exist between primary squamous cell lung carcinomas with and without lymph node involvement and within carcinomas with lymph node involvement. The data suggest that various metastasis profiles exist.

Non-small cell lung cancer clinical trials with trastuzumab: their foundation and preliminary results

The overexpression of HER2, a transmembrane glycoprotein tyrosine kinase, has been implicated in mitogenesis, cell survival, invasion and angiogenesis. Preclinical evidence suggests that HER2 overexpression contributes to tumor progression in non-small cell lung cancer (NSCLC) and retrospective clinical correlative studies show that it is probably associated with poor clinical outcome. Trastuzumab (Herceptin, Genentech Inc., South San Francisco, CA) is a recombinant humanized monoclonal antibody that targets HER2 and is currently approved for use in the treatment of patients with HER2-overexpressing metastatic breast cancer. Two primary mechanisms proposed for the activity of trastuzumab are downregulation of HER2 and induction of antibody-dependent cell-mediated cytotoxicity. Evidence from preclinical studies of trastuzumab in NSCLC and other cell lines, the presence of HER2 overexpression in NSCLC clinical specimens and the clinical benefit derived from trastuzumab in phase II and III metastatic breast cancer trials have led to the development of clinical trials of trastuzumab in NSCLC. Phase II studies of trastuzumab in patients with stage IIIB or IV NSCLC are being conducted to test the efficacy of trastuzumab as a single agent or in combination with chemotherapy. Preliminary results show combinations of chemotherapy plus trastuzumab are well tolerated, with encouraging response rates of 21-40%. A randomized phase II trial of chemotherapy with or without trastuzumab showed promise in a small subgroup of patients with 3+ HER2 overexpression by immunohistochemistry or HER2 DNA amplification by fluorescence in situ hybridization. Taken together, these data indicate that trastuzumab warrants further investigation in a clinical study in selected patients with NSCLC.

Immunohistochemical study of thyroid transcription factor-1 and HER2/neu in non-small cell lung cancer: strong thyroid transcription factor-1 expression predicts better survival

The relationship of thyroid transcription factor-1 (TTF-1) and HER2/neu expression in non-small cell lung cancer (NSCLC) with multiple parameters including survival were examined. Patients with primary NSCLC who had surgical resection and follow-up of at least 5 years were included in the study. There were 57 patients (38 men and 19 women), 44 to 75 years old (median age, 61 years); 28 patients had adenocarcinoma (AD) and 29 had squamous cell carcinoma. Tumors were examined for TTF-1 and HER2/neu expression using formalin-fixed, paraffin-embedded tissue. Clinical and follow-up data were obtained from the hospital records and Cancer Center database. Representative tumor sections were stained using standard immunohistochemical technique and commercial antibodies for TTF-1 (clone 8G7G3/1, Dako) and HER2/neu (polyclonal, Dako). Tumors were graded as negative (<5%), weak positive (5-49%), and strong positive (>50%), based on the percentage of positively stained tumor cells. Statistical analyses were performed using log-rank test, Pearson and Spearman correlations, and Kaplan-Meier survival curves. TTF-1 expression was seen in 45.6% of all tumors (80% of ADs and 14% of squamous cell carcinomas). Eighteen patients with tumors showing strong TTF-1 expression had significantly better survival compared with the 39 patients whose tumors showed negative or weak TTF-1 expression, although many more of the higher stage AD had strong TTF-1 staining than stage I AD. The TTF-1 expression did not correlate with tumor differentiation and was considered an independent predictor of survival. Seventeen of the 18 tumors with strong TTF-1 expression were ADs. Only eight of 57 (17%) tumors showed HER2/neu expression; seven of these eight were ADs. Although HER2/neu expression and survival did not show correlation, the majority of those ADs with weak or strong HER2/neu staining also had strong TTF-1 staining, were mostly stage I tumors. and had overall longer survival. All patients with stage I disease showed better 5-year survival compared with those with stages II and III. Hispanic patients had significantly worse survival compared with Caucasians and African Americans. The results of this study suggest that strong expression of TTF-1 is an independent predictor of better survival and may be a useful prognostic tool for evaluation of patients with NSCLC.

HER-2/neu overexpression in patients with radically resected nonsmall cell lung carcinoma. Impact on long-term survival

BACKGROUND

Using immunohistochemistry, the authors prospectively investigated the expression of HER-2/neu protein in radically resected specimens of nonsmall cell lung carcinoma (NSCLC) and evaluated its impact on long-term prognosis.

METHODS

Between January 1991 and February 1992, surgical specimens from 130 consecutive patients who underwent radical resection for NSCLC (60 squamous cell carcinoma, 48 adenocarcinoma cases, and 22 large cell carcinomas) and that were staged (according to the TNM staging system) pathologically as Stage I (41 cases [32%]), Stage II (37 cases [28%]), and Stage IIIA (52 cases [40%]) were investigated for the expression of HER-2/neu using an avidin-biotin complex immunohistochemical technique. A semiquantitative four-stage grading system was used (0%, 1-5%, 6-20%, and > 20% positive cells) and an average number of 1500 cells/section was considered. Data were correlated with clinical and pathologic variables.

RESULTS

Normal bronchial tissue was found to be completely negative for HER-2/neu expression whereas 21 of the 130 tumor specimens (16%) were positive (range 1-> 20%). HER-2/neu positivity did not appear to differ significantly among pathologic stages and histotypes. Using a predetermined cutoff value of 5% positive cells, 15 tumor specimens (12%) were found to be above this value. The median survival time (85 weeks vs. 179 weeks) and overall survival rate were significantly lower in patients with > 5% HER-2/neu-positive tumors (hazard ratio for the group with > 5% positive cells: 2.94, 95% confidence interval, 1.62-5.34; P < 0.0004). On multivariate analysis, HER-2/neu and extent of tumor emerged as independent factors for disease-related mortality.

CONCLUSIONS

In NSCLC, the negative impact of HER-2/neu overexpression on survival was maintained in the long-term follow-up of radically resected patients. HER-2/neu overexpression may be a valuable prognostic factor as well as a potential target for biologic therapies.

Trastuzumab in the treatment of non-small cell lung cancer

Trastuzumab is a humanized monoclonal antibody that binds to human epidermal growth factor-2 (HER2) and is approved by the US Food and Drug Administration for the treatment of advanced breast cancer that overexpresses HER2/neu protein. Preclinical data suggests a role for trastuzumab in the treatment of non-small cell lung cancer (NSCLC). HER2 protein is overexpressed in 20% to 66% of resected NSCLC tumors, and has been shown to predict poor patient outcome in multiple series. Experiments with NSCLC cell lines show that HER2 overexpression increases chemoresistance, invasiveness, and metastatic potential of the cells. In mouse xenograft experiments, trastuzumab halts tumor growth and is synergistic with cytotoxic chemotherapy. Ongoing phase II trials are showing that trastuzumab can be added to standard chemotherapy in the treatment of patients with advanced NSCLC without additional toxicity, and with promising efficacy. Whether trastuzumab will show a clear benefit for patients with NSCLC, either alone or in combination with established chemotherapy, remains to be proven in phase III testing.

Targeting HER2 in other tumor types

The human epidermal growth factor receptor-2 (HER2) is overexpressed/amplified in a range of tumor types including breast, ovarian, bladder, salivary gland, endometrial, pancreatic and non-small-cell lung cancer (NSCLC). HER2 is implicated in disease initiation and progression, associated with poor prognosis, and may also predict the response to chemotherapy and hormonal therapy. Anti-HER2 monoclonal antibodies (MAbs) have been designed to specifically antagonize the function of the HER2 receptor in HER2-positive tumors. Clinical phase II and III trials have demonstrated the efficacy of the humanized anti-HER2 MAb, trastuzumab (Herceptin), both as a single agent and in combination with chemotherapy in HER2-positive, metastatic breast cancer patients. However, the prevalence of HER2 overexpression/amplification in various tumor types raises the possibility of using anti-HER2 MAbs to antagonize the abnormal function of overexpressed HER2 receptors in HER2-positive tumors other than breast. Preliminary in vitro studies indicate that anti-HER2 MAbs suppress the proliferation of ovarian, gastric and NSCLC cell lines that overexpress the HER2 receptor. These results indicate that anti-HER2 MAbs may have important therapeutic significance in patients presenting with these or other human carcinomas. Clinical trials are either planned or underway to assess the therapeutic role of trastuzumab in NSCLC, bladder and ovarian cancer.

The impact of immune responses on lung cancer and the development of new treatment modalities

OBJECTIVE

This presentation covers predominantly review data in relation with immune responses initiating and accompanying lung carcinogenesis or- on the contrary-contributing to novel therapeutic developments. Occasionally, personal findings will be considered. RESULTS 1 OF IMMUNE DEFICIENCY: It is known for several decades that cancer incidence (several sites) is increased in subjects receiving immunosuppressive therapy, e.g. to avoid transplant rejection, or suffering from AIDS. We have observed that in areas heavily polluted by industrial activities, resulting in immune deficiency, cancer incidence is increased, notably for lung cancer. On the other hand, neoplastic cells are able to escape the host's immune responses by inducing apoptosis of the effector T lymphocytes. Apoptosis in T-cells is triggered by the interaction of the membrane receptor Fas with its normal ligand Fas L, or an activating antibody. Now lung carcinoma cells have been shown to express Fas L, enabling them to destroy cytolytic T cells. RESULTS 2 OF IMMUNE TREATMENT: It is well over a century ago that interest in the immunotherapy of cancer was aroused by the observation of tumour regressions concomitant with bacterial infection, an observation leading to the development of 'Coley's toxin', a mixture of killed bacteria (presently known to act through the presence of TNF-alpha). Since these long-standing empirical attempts, a lasting search for immune control of cancer has been initiated, comprising such different approaches as active non-specific immunotherapy, active specific immunotherapy, approaches based on the use of monoclonal antibodies, as well as those depending on cellular immunity and the development of adoptive immunotherapy, and the use of peptide vaccines. These different approaches will be described and their results presented.

CONCLUSION

Present state-of-the-art will be discussed and new pathways for development evoked; better understanding of immune mechanisms is opening new avenues for improved treatment efficacy.

Identification of HER-2/neu overexpression and the clinical course of lung carcinoma in non-smokers with chronic lymphocytic leukemia

Patients with CLL have an excess risk of developing second primary malignancies. The etiology of this excess risk is unclear, and has been thought to be related to smoking. HER-2/neu overexpression has evolved as a prognostic/predictive factor in some solid tumors. We reviewed our experience with non-smokers who had CLL and subsequently developed lung carcinoma, in an effort to better understand the clinical course of these patients, and to evaluate the role of HER-2/neu overexpression. We reviewed the records of all patients who had a diagnosis of both CLL and lung carcinoma between 1986 and 2000. HER-2/neu overexpression was estimated by immunohistochemistry (IHC) using the Hercep test (DAKO). An IHC score of 2+ or greater was considered positive. Overall survival was calculated from the date of diagnosis of lung carcinoma by the Kaplan-Meier product limit method. Fourteen non-smokers in whom a diagnosis of CLL was made at least 6 months prior to the diagnosis of lung carcinoma were identified. The median age for diagnosis of CLL in this group was 67 years while that for lung carcinoma was 70 years. The lung carcinomas included 10 non-small cell (NSCLC) and four small cell (SCLC) carcinomas. Nine specimens (six NSCLC and three SCLC) showed HER-2/neu overexpression. Interestingly, 90% of patients with advanced stage cancer (stage IIIB/IV NSCLC or extensive SCLC) overexpressed HER-2/neu. The presence of CLL did not alter outcome in patients with early stage lung cancer. However, after adjustment for age and performance status, patients with advanced stage NSCLC and CLL had a worse than expected outcome. HER-2/neu overexpression (independent of smoking) may be involved in the development/progression of lung cancer in patients with CLL, and has an associated worse outcome. It is appropriate to consider heightened surveillance of CLL patients for lung carcinoma.

Overexpression of c-erbB2 protein correlates with disease-stage and chromosomal gain at the c-erbB2 locus in non-small cell lung cancer

Overexpression of the c-erbB2 protein is observed in a variety of malignancies including non-small cell lung cancer (NSCLC). We aimed to determine the rate of c-erbB2-overexpression in our tumour collection and to clarify its correlation with the chromosomal status at the c-erbB2 locus 17q21 in NSCLC. Eighty-nine NSCLC were analysed immunohistochemically using a polyclonal c-erbB2 antibody (DAKO). The staining was scored according to the guidelines of the Clinical Trial Assay recommendations (0-3+). Of these, 44 cases were also analysed by comparative genomic hybridisation (CGH). Overexpression was observed in 37% of the cases (score>1) which was associated with higher disease stages and a positive nodal status in adenocarcinomas. Chromosomal gains at 17q21 were clearly correlated with overexpression of the gene (P=0.009). In addition, there was a highly significant correlation between the c-erbB2 expression comparing the whole section immunostaining analysis and a 127 lung tumour tissue array which included 74 of the 89 cases that were analysed by the classical procedure. We conclude that c-erbB2 is a marker of tumour progression in NSCLC which can be observed on protein level and reflects chromosomal alterations at 17q21.

Protein overexpression and gene amplification of c-erb B-2 in pulmonary carcinomas: a comparative immunohistochemical and fluorescence in situ hybridization study

Amplification of the c-er bB-2 gene (located on 17q11.2--12) is accompanied by overexpression of its cell surface receptor product, p185(ERBB2). In pulmonary carcinomas, however, there has been disagreement between the reported frequencies of gene amplification and overexpression. To clarify their relationship, the correlation between the cellular expression of p185(ERBB2) and the level of c-erb B-2 gene amplification was studied. A total of 195 pulmonary carcinomas (182 primary and 13 metastatic) were examined immunohistochemically using a polyclonal antibody, which recognizes the internal domain of the human c-erb B-2 protein, and positive tumors were further examined for the gene amplification by dual-color fluorescence in situ hybridization using probes for centromere 17 and 17q11.2--12. By immunohistochemistry, distinct membrane staining was found in an adenocarcinoma, a large cell carcinoma and a metastatic carcinoma from the breast, and cytoplasmic and/or faint membranous staining was observed in 23 non-small cell lung carcinomas. It was in the two primaries and the metastatic carcinoma that more than 8-fold amplification of c-erb B-2 was found by fluorescence in situ hybridization. Especially, in the two primary carcinomas, tumor cells had amplified genes with the signals forming one or two clusters, indicating that the amplified gene was present in homogeneously staining regions. Among the 23 tumors, three tumors showed low-level amplification (less than 3-fold), which was differentiated from polysomy 17 found in the other two. In the 30 non-small cell lung carcinomas selected at random from 151 with negative immunostaining, there were five trisomy 17, but no tumors with the gene amplification. This suggests that although c-erb B-2 amplification in pulmonary carcinoma is rare, it occurs in the form of a homogeneously staining region and is thought to control the overexpression of the protein in the cell membrane. New adjuvant therapy using a humanized antibody to the oncoprotein may be beneficial to patients with these tumors.

c-erbB-2 expression in small-cell lung cancer is associated with poor prognosis

Small-cell lung cancer (SCLC) carries a bad prognosis despite good initial response to chemotherapy. It is therefore important to identify molecular markers that influence survival as potential new therapeutic targets. In our study, expression of the tyrosine kinase c-erbB-2 (HER2/neu) receptor in tumor tissues of 107 consecutive newly diagnosed patients with primary SCLC was quantified using a monoclonal antibody directed against the c-terminal domain of c-erbB-2. A clear-cut positive expression of c-erbB-2 was observed in 13% of patients. Surprisingly, c-erbB-2 was an independent prognostic factor (RR = 2.16; p = 0.014) when a proportional-hazard model was adjusted to stage (limited vs. extensive disease) and performance status (WHO I-IV), the most relevant clinical parameters. Similarly, a significant association between c-erbB-2 and survival was obtained if a larger number of clinical parameters were included into the analysis, namely response to chemotherapy, TNM stage, lactate dehydrogenase (LDH), neuron-specific enolase (NSE), gender and age (p = 0.033). Interestingly, c-erbB-2 expression was more relevant for patients with advanced tumors. In the subgroup of patients with bad performance status (WHO II-IV), median survival of patients with undetectable c-erbB-2 expression was 274 days compared with only 23 days for patients with clear-cut positive c-erbB-2 immunohistochemistry (p = 0.0031; log-rank test). Similar results were obtained for patients with extensive disease (p = 0.028) and high TNM stages (T>2 or N>1 or M1; p < 0.068, all comparisons). In contrast, c-erbB-2 expression was not associated with survival in patients with limited disease (p = 0.97), low TNM stages (p > 0.56, all comparisons) and good performance status (p = 0.97). In conclusion, c-erbB-2 is expressed in more than 10% of SCLC. Expression of c-erbB-2 is an independent prognostic factor of survival. The effect of c-erbB-2 expression seems to become more important in advanced stages of the disease. Since c-erbB-2 is a therapeutical target in other types of cancer, further studies to identify the role of c-erbB-2 in SCLC are clearly warranted.

Cell biology of lymphatic metastasis. The potential role of c-erbB oncogene signalling

Lymphatic metastases are an important indicator of the malignancy of epithelial cancers. Empirical clinical observations associating specific genetic abnormalities with tumour progression, allied with basic laboratory investigations, are providing not only improved prognostic and diagnostic opportunities, but also a detailed understanding of the molecular machinery of metastasis. One such association--between the c-erbB oncogene family and metastasis--has proved particularly instructive. Functional links between over-expression (and occasionally mutational activation) of c-erbB-1 (EGFR) and c-erbB-2 and specific phenotypes of metastatic cells have been elucidated. Activated c-erbB oncogenes potentiate tumour cell adhesion to endothelial cells and upregulate VEGF, potentially facilitating angiogenesis and vascular invasion. In addition, cells over-expressing these oncogenes frequently show aberrant cell-cell and cell-matrix interactions, mediated by changes in integrin and cadherin function. Thirdly, both EGFR and c-erbB-2 signalling can significantly upregulate specific matrix metalloproteinases, key enzymes involved in angiogenesis and invasion. Finally, c-erbB receptors linked to the actin cytoskeleton and highly expressed on invadopodia, are thought to assist cell migration. Taken together, these observations suggest that such receptors can act as "master switches" in metastasis, whose activation co-ordinately controls events normally utilised in development, now subverted by the metastatic cell. As such, they represent ideal targets for therapeutic intervention.

Effect of HER2/neu Expression on Survival in Non–Small-Cell Lung Cancer

Major prognostic factors for early-stage non-small-cell lung cancer (NSCLC) are tumor size and nodal status. It has been suggested that HER2/neu overexpression may be related to poor prognosis in NSCLC. We evaluated the significance of HER2/neu overexpression on survival in patients with NSCLC. Data were collected on 239 patients treated surgically for stage I/II NSCLC between 1987 and 1996. None of the patients received adjuvant chemotherapy or radiation. Formalin-fixed, paraffin-embedded tumor tissue samples were stained with p185/HER2 receptor antibody. Results were reported as positive (2+, 3+) or negative (0, 1+) (Group A). A separate analysis considered only 3+ as positive (Group B). HER2/neu overexpression was seen in 18% in Group A (43 of 239) and 6% in Group B (15 of 239). HER2/neu overexpression was highest in bronchoalveolar cell carcinoma and adenocarcinoma. More stage I tumors were positive than stage II in both groups, but this was significant only in Group A (21% vs. 7%, P = 0.02). No difference was seen with age, gender, or grade for either group. In Group A, the relapse rate was 55% for HER2/neu-overexpressing tumors and 31% for HER2/neu-negative tumors (P = 0.003). Median time to relapse in patients with HER2/neu-positive tumors was 2.9 years; it was not reached in patients with HER2/neu-negative tumors. Median survival of patients with HER2/neu-positive tumors was 3.6 years compared to 5 years in patients with HER2/neu-negative tumors (P = 0.66). In Group B, the relapse rate was 60% for HER2/neu-overexpressing tumors and 33% for negative tumors (P = 0.036). Median time to relapse was 3.4 years in HER2/neu positive and had not been reached in negative tumors. There was no difference in 5-year survival rates for both groups (47% for HER2/neu positive and 50% for negative, P = 0.66).

Comparative methodological analysis of erbB-2/HER-2 gene dosage, chromosomal copy number and protein overexpression in breast carcinoma tissues for diagnostic use

AIMS

This study was performed to test the validity of different methods for determining the status of the erbB-2/HER-2 oncogene in breast cancer tissues for diagnostic use.

METHODS AND RESULTS

Forty formalin-fixed, paraffin-embedded breast carcinomas were investigated by fluorescence in situ and comparative genomic hybridization (FISH, CGH) as well as by immunohistochemistry (IHC) using Dako-HercepTest and CB11 antibody (Ventana). Additionally, competitive-differential polymerase chain reaction (cdPCR) was performed on frozen samples to estimate gene dosage alterations of erbB-2/HER-2. Amplification was detected in 12-23% and protein overexpression in 16-68% of the cases, depending on the methodology and/or the reagent used. Perfect concordance (100%) was found between the results of cdPCR and CB11-IHC, and a 97% concordance between FISH and CB11-IHC. The concordance between Dako-HercepTest and CB11-IHC was 78%: seven of eight 2+ carcinomas with the Dako-HercepTest were classified as nonamplified using FISH.

CONCLUSIONS

Our results indicate that high-level expression as well as normal erbB-2/HER-2 status of breast carcinomas can be detected reliably both by IHC and gene dosage assessment in paraffin material for diagnostic use. However, borderline results, especially those with 2 + immunopositivity, should be interpreted with caution and increased emphasis should be given to other clinical and prognostic information available.

Multiple molecular marker testing (p53, C-Ki-ras, c-erbB-2) improves estimation of prognosis in potentially curative resected non-small cell lung cancer

A prospective study was performed in patients with non-small cell lung cancer (NSCLC) to evaluate the prognostic importance of multiple molecular marker (p53, c-Ki-ras, c-erbB-2) testing. 103 patients with potentially curative resections (RO resection) for NSCLC in histopathological stages I-IIIA were included. SSCP analysis and DNA sequencing for p53 and c-Ki-ras genes were performed on paired tumour and normal lung tissue samples and immunohistochemistry (c-erbB-2) was done on frozen tissue sections with a specific anti-c-erbB-2 monoclonal antibody. 46/103 (44.6%) NSCLC showed p53 mutations and 17/103 (16.5%) c-Ki-ras mutations including 12/37 (32.4%) adenocarcinomas. Overexpression of c-erbB-2 (p185) was detected in 56/103 (54.4%) tumours. 24/103 (23.3%) NSCLC were negative for alterations in all 3 parameters (c-Ki-ras, p53 and p185) whereas 79/103 (76.7%) were positive for at least one of the 3 parameters. In a regression model including a multiple molecular marker parameter (negative for all 3 markers versus positive for at least one marker), histopathological stage (P<0.00001), respectively the pT (P<0.01) and pN (P<0.00001) categories and the multiple molecular marker parameter (P<0.01) were of significant prognostic importance. This study demonstrates that testing 3 molecular markers (c-Ki-ras, p53 and c-erbB-2) improves estimation of prognosis compared to single marker testing and appears to define low (82.6%+/-7.9% 5-year survival) and high risk (40.2%+/-5.5% 5-year survival) groups for treatment failure in potentially curative (RO) resected NSCLC.

What is HER2?

The focus of recent research into the cause of cancer has been the cell systems controlling growth. This has shown that mutations affecting growth factor receptors are involved in oncogenesis. The human epidermal growth factor receptor (HER) family is one of the best characterized systems in breast cancer and has important functions in the control of normal growth regulation. HER2 has a central role in the HER family, interacting with the other members of this receptor family to potentiate intracellular signalling. Although our understanding of how HER2 functions and is regulated is limited, studies have linked HER2 gene amplification/receptor overexpression to cancer development. HER2 gene amplification/receptor overexpression is observed in a significant proportion of various tumour types, occurs relatively early during cancer progression and is associated with poor prognosis in women with breast cancer. Knowing the HER2 status of patients with breast cancer will become increasingly important for making management decisions.

The ets protein PEA3 suppresses HER-2/neu overexpression and inhibits tumorigenesis

Because HER-2/neu overexpression is important in cancer development, we looked for a method of suppressing the cell transformation mediated by HER-2/neu overexpression. We have identified that the DNA-binding protein PEA3, which is encoded by a previously isolated gene of the ets family, specifically targeted a DNA sequence on the HER-2/neu promoter and downregulated the promoter activity. Expression of PEA3 resulted in preferential inhibition of cell growth and tumor development of HER-2/neu-overexpressing cancer cells. This is a new approach to targeting HER-2/neu overexpression and also provides a rationale to the design for repressors of diseases caused by overexpression of pathogenic genes.