The Role of Human Epidermal Growth Factor Receptor 2 as a Prognostic Factor in Lung Cancer: A Meta-Analysis of Published Data

Worldwide variations in EGFR somatic mutations: a challenge for personalized medicine

Two studies recently reported around 10% of EGFR activating mutations in triple negative breast cancers from Asian patients. However, we did not find any EGFR activating mutation in a series of 229 breast tumor samples from European patients. Like in lung cancer, the EGFR mutation profiles seem to be related to the ethnical origin of patients. This is an important point that should be considered when developing anti-EGFR therapies.

Impact of HER2 and PTEN simultaneous deregulation in non-small cell lung carcinoma: correlation with biological behavior

BACKGROUND

HER2/neu overexpression due to gene amplification is an important factor in breast cancer, modifying the sensitivity to anti-HER2 monoclonal antibody therapy. The clinical significance of HER2 expression in non small cell lung carcinoma (NSCLC) is currently under evaluation. The tumor suppressor gene PTEN negatively regulates the HER2/PI3K/Akt signalling pathway. The purpose of this study was to evaluate the role of simultaneous alteration in HER2 and PTEN protein expression in relation to biological behaviour of NSCLCs.

MATERIALS AND METHOD

Protein expression was determined by immunohistochemistry in sixty-one (n=61) NSCLC cases along with CISH for HER2 gene analysis and detection of chromosome 17 aneuploidy. Patients were followed-up for a period of 34 to 41 months after surgery.

RESULTS

HER2 overexpression (2+/3+ score) was detected in 17 (27.9%) patients while loss of PTEN expression was observed in 24 (39.3%) cases, low expression in 29 (47.6%) and overexpression in 8 (13.1%). Simultaneous HER2 overexpression and PTEN low/loss of expression were correlated with metastasis (71.4% vs 36.2% p=0.03) . Analysis in the subgroup of 22 patients of pTNM stage III with lymph node status N1 or N2 revealed that there was a relationship between the number of positive regional lymph node groups and simultaneous deregulation of the two genes (p=0.04). Multivariate analysis determined that HER2 overexpression was associated with an increasing risk of developing metastases (OR: 4.3; 95%CI: 1.2-15.9; p: 0.03) while PTEN overexpression was associated with lower risk (OR: 0.1; 95%CI: 0.1, 1.0; p: 0.05).

CONCLUSIONS

Simultaneous HER2/PTEN deregulation is a significant genetic event that leads to a more aggressive phenotype of NSCLC.

The role of cyclin D1 expression and patient's survival in non-small-cell lung cancer: a systematic review with meta-analysis

BACKGROUND

The role of cell-cycle protein cyclin D1 in lung cancer remains controversial. To clarify its impact on survival in non-small-cell lung cancer (NSCLC), we performed a meta-analysis on the currently available medial literature to quantitatively assess its role on survival of NSCLC according to cyclin D1 status.

METHOD

Published studies that investigated the association between cyclin D1 expression and NSCLC survival were identified. Meta-analysis was performed by using a DerSimonian-Laird model. Funnel plot was used to investigate publication bias and sources of heterogeneity were identified by using meta-regression analysis.

RESULT

A total of 24 studies with 2731 patients were evaluable for this meta-analysis. No statistical significance was found that cyclin D1 expression was associated with poor prognosis in NSCLC (hazard ratio 1.08 [95% CI, 0.80-1.45]) without publication bias found. But there was significant heterogeneity present; meta-regression analysis was used to explore the sources of heterogeneity and revealed that the outcome of analysis was influenced by cutoff values and ethnicity. No difference between positive and negative studies on study quality assessment was present.

CONCLUSION

The cyclin D1 expression is unlikely to be useful as a prognostic marker for NSCLC in clinical practice from current evidence. The conclusion should be confirmed by a large well-designed prospective study.

Expression and clinical significance of leptin, the functional receptor of leptin (OB-Rb) and HER-2 in non-small-cell lung cancer: a retrospective analysis

BACKGROUND

The human epidermal growth factor receptor 2 (HER-2) and leptin/OB-R system have been reported to be intertwined in several cancer types. However, limited research has been conducted with regard to this interaction in lung cancers. In this study, we investigated the relationship between the expression levels of these proteins and the development, progression and prognosis of non-small-cell lung cancer (NSCLC).

METHODS

The expression of leptin, OB-Rb and HER-2 was evaluated in 100 NSCLC specimens by immunohistochemistry, with normal lung tissue as controls. The relationships between their expression levels and clinicopathological factors were evaluated by correlation analysis. Univariate and multivariate analyses were used to determine the associations between the expression levels of these proteins and the survival of NSCLC patients.

RESULTS

Leptin was expressed in 71 and 25% (P < 0.05) of NSCLC and normal lung tissues, respectively, while OB-Rb was expressed in 62 and 31% (P < 0.05), respectively. Overexpression of HER-2 was detected in 53% of NSCLC tissues versus 0% of normal lung tissues (P < 0.05). A significant association was found between the expression levels of leptin and OB-Rb (P = 0.024), and between tumor-node-metastasis (TNM) stage and HER-2 expression (P = 0.003). Univariate survival analysis showed that TNM stage (P < 0.001) and leptin expression (P = 0.009) influenced survival time. Multivariate analysis suggested that TNM stage [hazard ratio (HR) 1.63, 95% confidence interval (CI) 1.30-2.04, P < 0.001] and leptin expression (HR 1.69, 95% CI 1.01-2.80, P = 0.044) were independent prognostic factors for NSCLC.

CONCLUSIONS

The expression of leptin, OB-Rb and HER-2 was significantly higher in NSCLC tissues than in normal lung tissues. The expression of leptin is an independent prognostic factor for NSCLC.

Immune effects of trastuzumab

Trastuzumab's targeted therapy has become a stronghold for human epidermal growth factor receptor 2 positive breast cancer patients. This humanized monoclonal antibody binds to the extracellular juxta-membrane domain of HER2 and inhibits the proliferation and survival of HER2 dependent cancer cells. The ways by which this molecule exerts its action have been partially elucidated but several new mechanisms are being constantly identified. Several new agents are being introduced that interfere with HER2. Several new immunotherapy strategies are being introduced in order to direct the immune system against cells and tissues that aberrantly overexpressed HER2. We review the strategies currently adopted and those suggested against HER2 expressing tumors.