Serum peptide expression and treatment responses in patients with advanced non-small-cell lung cancer.

Epidermal growth factor receptor (EGFR) mutation is an important predictor for response to personalized treatments of patients with advanced non-small-cell lung cancer (NSCLC). However its usage is limited due to the difficult of obtaining tissue specimens. A novel prediction system using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been reported to be a perspective tool in European countries to identify patients who are likely to benefit from EGFR tyrosine kinase inhibitor (TKI) treatment. In the present study, MALDI-TOF MS was used on pretreatment serum samples of patients with advanced non-small-cell lung cancer to discriminate the spectra between disease control and disease progression groups in one cohort of Chinese patients. The candidate features for classification were subsequently validated in a blinded fashion in another set of patients. The correlation between plasma EGFR mutation status and the intensities of representative spectra for classification was evaluated. A total of 103 patients that were treated with EGFR-TKIs were included. It was determined that 8 polypeptides peaks were significant different between the disease control and disease progression group. A total of 6 polypeptides were established in the classification algorithm. The sensitivity of the algorithm to predict treatment responses was 76.2% (16/21) and the specificity was 81.8% (18/22). The accuracy rate of the algorithm was 79.1% (34/43). A total of 3 polypeptides were significantly correlated with EGFR mutations (P=0.04, P=0.03 and P=0.04, respectively). The present study confirmed that MALDI-TOF MS analysis can be used to predict responses to EGFR-TKI treatment of the Asian population where the EGFR mutation status differs from the European population. Furthermore, the expression intensities of the three polypeptides in the classification model were associated with EGFR mutation.

A comparison of ARMS and direct sequencing for EGFR mutation analysis and tyrosine kinase inhibitors treatment prediction in body fluid samples of non-small-cell lung cancer patients.

BACKGROUND: Epidermal growth factor receptor (EGFR) mutation is strongly associated with the therapeutic effect of tyrosine kinase inhibitors (TKIs) in patients with non-small-cell lung cancer (NSCLC). Nevertheless, tumor tissue that needed for mutation analysis is frequently unavailable. Body fluid was considered to be a feasible substitute for the analysis, but arising problems in clinical practice such as relatively lower mutation rate and poor clinical correlation are not yet fully resolved. METHOD: In this study, 50 patients (32 pleural fluids and 18 plasmas) with TKIs therapy experience and with direct sequencing results were selected from 220 patients for further analysis. The EGFR mutation status was re-evaluated by Amplification Refractory Mutation System (ARMS), and the clinical outcomes of TKIs were analyzed retrospectively. RESULTS: As compared with direct sequencing, 16 positive and 23 negative patients were confirmed by ARMS, and the other 11 former negative patients (6 pleural fluids and 5 plasmas) were redefined as positive, with a fairly well clinical outcome (7 PR, 3 SD, and 1 PD). The objective response rate (ORR) of positive patients was significant, 81.3% (direct sequencing) and 72.7% (ARMS) for pleural fluids, and 80% (ARMS) for plasma. Notably, even reclassified by ARMS, the ORR for negative patients was still relatively high, 60% for pleural fluids and 46.2% for plasma. CONCLUSIONS: When using body fluids for EGFR mutation analysis, positive result is consistently a good indicator for TKIs therapy, and the predictive effect was no less than that of tumor tissue, no matter what method was employed. However, even reclassified by ARMS, the correlation between negative results and clinical outcome of TKIs was still unsatisfied. The results indicated that false negative mutation still existed, which may be settled by using method with sensitivity to single DNA molecule or by optimizing the extraction procedure with RNA or CTC to ensure adequate amount of tumor-derived nucleic acid for the test.

[Erlotinib in the treatment of advanced non-small-cell lung cancer (NSCLC)].

OBJECTIVE: Erlotinib is a small-molecule inhibitor of EGFR tyrosine kinase, showing a significant improvement of survival in non-small-cell lung cancer (NSCLC) after the failure of front-line chemotherapy. The aim of this study was to evaluate the antitumor efficacy and toxicity of Erlotinib in the treatment of advanced NSCLC patients. METHODS: A total of 104 patients with advanced NSCLC admitted in our department during December 2006 to November 2008 were enrolled in this study. Eligible patients received oral Erlotinib 150 mg/d until disease progression or intolerable toxicity. Best clinical response was determined using RECIST criteria, the adverse events were evaluated according to the NCI criteria. RESULTS: The total effective rate was 27.9% (29/104) and the clinical benefit was 76.0% (79/104). The median progression-free survival was 5.1 months (95%CI 4.0 - 8.0). The median survival time was 13.1 months (95%CI 10.0 - 15.7). The 1-year survival rate was 61.5%. Significant survival benefit from erlobinib therapy was observed for patients with good personal status (HR 0.56, P = 0.006), adenocarcinoma (HR 0.43, P = 0.004) and skin rash (HR 0.46, P = 0.005). But patients with smoking (HR 2.75, P < 0.001) and liver metastasis (HR 2.91, P = 0.002) add the risk of death. The adverse events were mild (grade < or = 2), most common toxicities were skin rash in 73.1% (76/104) and diarrhea in 41.3% (43/104). Only 6.7% (7/104) patients got adverse events of grade > or = 3. CONCLUSION: Erlotinib is an effective and well-tolerated treatment option for advanced NSCLC and could offer an alternative for patients after the failure of first-line chemotherapy, unsuitable for or not wishing to receive chemotherapy.

Identification of differentially expressed genes contributing to radioresistance in lung cancer cells using microarray analysis.

Radiotherapy has played a key role in the control of tumor growth in many cancer patients. It is usually difficult to determine what fraction of the tumor cell population is radioresistant after a course of radiotherapy. The response of tumor cells to radiation is believed to be accompanied by complex changes in the gene expression pattern. It may be possible to use these to sensitize radioresistant tumor cells and improve radiocurability. Based on the biological effects of ionizing radiation, in the present study, we developed one oligonucleotide microarray to analyze the expression of 143 genes in cells of two lung cancer cell lines with different radiosensitivities. Compared to NCI-H446 cells, expression of 18 genes significantly increased the basal levels in the radioresistant A549 cells, in which eight genes were up-regulated and 10 genes were down-regulated. In A549 cells irradiated with 5 Gy, 22 (19 up-regulated and three down-regulated) and 26 (eight up-regulated and 18 down-regulated) differentially expressed genes were found 6 and 24 h after irradiation, respectively. In NCI-H446 cells, the expression of 17 (nine up-regulated and eight down-regulated) and 18 (six up-regulated and 12 down-regulated) genes was altered 6 and 24 h after irradiation, respectively. RT-PCR was performed, and we found that MDM2, BCL2, PKCZ and PIM2 expression levels were increased in A549 cells and decreased in NCI-H446 cells after irradiation. Genes involved in DNA repair, such as XRCC5, ERCC5, ERCC1, RAD9A, ERCC4 and the gene encoding DNA-PK, were found to be increased to a higher level in A549 cells than in NCI-H446 cells. Antisense suppression of MDM2 resulted in increased radiosensitivity of A549 cells. Taken together, these results demonstrate the possibility that a group of genes involved in DNA repair, regulation of the cell cycle, cell proliferation and apoptosis is responsible for the different radioresistance of these two lung cancer cells. This list of genes may be useful in attempts to sensitize the radioresistant lung cancer cells.