Expression and function of miRNA in postoperative radiotherapy sensitive and resistant patients of non-small cell lung cancer

Purpose

To investigate the different miRNA expression profiles of postoperative radiotherapy sensitive and resistant patients of non-small cell lung cancer, explore their potential role and find some radio-sensitivity markers.

Materials and methods

Thirty non-small cell lung cancer patients who have been treated by postoperative radiotherapy were selected and were divided into radiotherapy sensitive group and resistant group according to overall survival and local or distant recurrence rate. Expression profile of miRNA in these two groups was detected by a microarray assay and the results were validated by quantitative RT-PCR and Northern blot. At the molecular level, the effect of one differently expressed miRNA (miR-126) on the growth and apoptosis of SK-MES-1 cells induced by irradiation was examined.

Results

Comparing with resistant patients, five miRNAs (miRNA-126, miRNA-let-7a, miRNA-495, miRNA-451 and miRNA-128b) were significantly upregulated and seven miRNAs (miRNA-130a, miRNA-106b, miRNA-19b, miRNA-22, miRNA-15b, miRNA-17-5p and miRNA-21) were greatly downregulated in radiotherapy sensitive group. Overexpression of miRNA-126 inhibited the growth of SK-MES-1 cells and promoted its apoptosis induced by irradiation. The expression level of p-Akt decreased in miRNA-126 overexpression group. After treating with phosphoinositidyl-3 kinase (PI3K) constitutively activator (IGF-1) and inhibitor (LY294002), miRNA-126 overexpression had no significant effects on the apoptosis of SK-MES-1 cells.

Conclusion

We found 12 differently expressed miRNAs in the radiotherapy sensitive and resistant non-small cell lung cancer samples. Moreover, our results showed miRNA-126 promoted non-small cell lung cancer cells apoptosis induced by irradiation through the PI3K-Akt pathway.     

Establishment and comparative characterization of novel squamous cell non-small cell lung cancer cell lines and their corresponding tumor tissue

Background

Cell lines play an important role for studying tumor biology and novel therapeutic agents. Particularly in pulmonary squamous cell carcinoma (SCC) the availability of cell lines is limited and knowledge about their representativeness for corresponding tumor tissue is scanty.

Materials and methods

We established three novel SCC cell lines from fresh tumor tissue of 28 donors, including 8 SCC. Two cell lines were derived from different localizations of the same donor, i.e. primary tumor and lymph node metastasis. This represents a so far unique combination in lung cancer. The genotypes, gene expression profiles and mutational status of epidermal growth factor receptor (EGF-R) and Kirsten rat sarcoma (k-ras) of the cell lines and their corresponding tumor tissue were analyzed and compared. Moreover, the molecular characteristics were related to functional properties of the cell lines. Those comprised proliferation, motility and chemosensitivity. The cell lines were authenticated by single tandem repeat DNA typing. Tumorigenicity was analyzed in a murine xenograft model.

Results

Comparative genomic hybridization and multiplex fluorescence in situ hybridization revealed essential genetic similarities between the cell lines and their corresponding tumor tissue, but indicated also some genetic evolution and clonal selection. EGF-R or k-ras mutations were not detected. Gene expression profiling showed various differences between tumor tissue and cell lines affecting gene clusters associated with immune response, adhesion, proliferation, differentiation and angiogenesis. However, there were also common gene expression patterns reflecting the relationship between cell lines and their corresponding tumor tissue. Moreover, the molecular characteristics of the tumor tissue and the descendent cell line were associated with functional properties of the latter. All cell lines showed a unique, heterozygous human DNA profile and one cell line displayed rapid tumor formation in mice.

Conclusions

Here, we demonstrate that cell lines represent a useful in vitro system for studying basic mechanisms in lung cancer, but cover only distinct molecular characteristics of the original tumor. Moreover, we present three novel, comprehensively characterized SCC cell lines.     

The stem cell gene “inhibitor of differentiation 1” (ID1) is frequently expressed in non-small cell lung cancer

Aims

Inhibitor of differentiation 1 (ID1) plays a role in cellular differentiation, proliferation, angiogenesis and tumor invasion. As shown recently, ID1 is positively regulated by the tyrosine kinase SRC in lung carcinoma cell lines and with that appears as a potential new therapeutic target in non-small cell carcinoma (NSCLC). To substantiate this hypothesis we examined ID1, SRC and matrix metalloproteinase-9 (MMP-9) immunohistochemically in human NSCLC specimens.

Methods

From 61 consecutive patient tissue samples of a tumor tissue bank a one core tissue microarray (TMA) was produced and whole slide tissue samples of preinvasive lesions used. The staining of commercial antibodies was assessed by the H-score. Statistical analyses based on Spearman's rank correlation coefficient.

Results

ID1 was expressed in the nucleus in 70% of squamous cell carcinomas and 50% of non-squamous cell carcinomas and in vascular endothelium of non-tumor tissue. Cytoplasmic staining was found in all samples for SRC and in 93% for MMP-9. ID1-positive tissue samples co-expressed SRC and MMP-9 in 94%. In non-squamous cell carcinomas, H-scores of ID1 and SRC correlated with each other (p = 0.04). H-score of MMP-9 correlated with tumor grade (p = 0.04). The carcinoma findings were reflected in preinvasive lesions.

Conclusions

We describe for the first time the immunohistochemical expression of ID1 in the majority of NSCLC samples. The almost general co-expression of ID1, SRC and MMP-9 supports their cooperation in vivo and warrants further investigation of ID1 as a therapeutic target.     

Bronchoscopic Microsampling is a Useful Complementary Diagnostic Tool for Detecting Lung Cancer

Purpose

Bronchoscopic microsampling (BMS) is a novel and direct method with which to obtain epithelial lining fluid (ELF) from the lungs. Analysis of DNA hypermethylation of tumor suppressor genes (TSGs) is expected to be a sensitive tool for the early detection of lung cancer. It has been reported that the existence of EGFR mutations and EML4-ALK gene rearrangements are related to the sensitivity of corresponding kinase inhibitors. We aimed to evaluate the suitability of ELF as a sample for analyzing molecular changes specific for lung cancer.

Patients and methods

We collected ELF from 61 lung cancer patients by BMS from the airway close to the peripheral lung nodule and purified the nucleic acids. We performed methylation specific PCR in each ELF as well as matched serum and tumor tissue for TSGs for DNA methylation analysis. We also examined EGFR mutations and EML4-ALK rearrangement.

Results

The sensitivity for detecting DNA hypermethylation in ELF vs serum was 74.1% vs 18.5%. We found 60.1% of patients had at least one hypermethylation in ELF, while only 27.9% had it in serum. Of note, DNA hypermethylation was detected even in stage I patients (60.0%) and the detection rate was almost the same level in each stage. We also found the sensitivity for detecting EGFR mutation in ELF vs serum was 58.3% vs 8.3%. We detected an EML4-ALK fusion gene using ELF in one patient.

Conclusions

BMS is an alternative method to detect cancer specific genetic and epigenetic alterations and will be a useful complementary diagnostic tool for lung cancer.

Summary

Investigation of genetic and epigenetic changes associated with lung cancer has clinical importance for its diagnosis and management. The clinical usefulness of bronchoscopic microsampling (BMS) in lung cancer has not yet been evaluated. This study demonstrates that BMS could be useful for detecting lung cancer specific molecular changes and valuable for early diagnosis and determination of treatment options for lung cancer.     

Synergistic cytotoxicity, inhibition of signal transduction pathways and pharmacogenetics of sorafenib and gemcitabine in human NSCLC cell lines

Introduction

Lung cancer is one of the most lethal tumors and, although standard chemotherapy produces clinical response, there has been little improvement in prognosis. Therefore, research effort has focused on target-specific agents, such as sorafenib, which blocks both the RAF/MEK/ERK signalling pathways and receptors involved in neovascularization and tumor progression, including VEGFR-2 and c-Kit. We investigated whether sorafenib would be synergistic with gemcitabine against NSCLC cell lines.

Materials and methods

Human lung cancer cells A549, CALU-1, CALU-6, H23 and HCC 827 were treated with sorafenib and gemcitabine, alone or in combination, and the cytotoxicity was assessed with CellTiter 96 Non-radioactive cell proliferation kit. Cell cycle and apoptosis were investigated with flow cytometry and fluorescence microscopy, respectively. Moreover, the effects of drugs on Akt (S473), c-Kit (Y823) and ERK (pTpY185/187) phosphorylation were studied with ELISA. Finally, quantitative PCR analysis was performed to assess whether sorafenib and gemcitabine modulated the expression of genes related to drug activity.

Results

Gemcitabine and sorafenib synergistically interacted on the inhibition of cell proliferation, and assessment of apoptosis demonstrated that drug associations increased the apoptotic index. Sorafenib reduced c-Kit and ERK activation and gemcitabine inhibited Akt phosphorylation. Moreover quantitative PCR showed that sorafenib modulated the expression of targets related to gemcitabine activity, while gemcitabine induced the expression of RKIP.

Conclusions

These data demonstrate that sorafenib and gemcitabine synergistically interact against NSCLC cells, through suppression of Akt, c-Kit and ERK phosphorylation, induction of apoptosis and modulation of dCK, RRM1, RRM2 and RKIP gene expression. The association between traditional cytotoxic agents with new target-specific agents, such as sorafenib, is a challenge for both clinical and preclinical future investigations in lung cancer treatments.     

Deregulation of cap-dependent mRNA translation increases tumour radiosensitivity through reduction of the hypoxic fraction

Background and purpose

Tumour hypoxia is an important limiting factor in the successful treatment of cancer. Adaptation to hypoxia includes inhibition of mTOR, causing scavenging of eukaryotic initiation factor 4E (eIF4E), the rate-limiting factor for cap-dependent translation. The aim of this study was to determine the effect of preventing mTOR-dependent translation inhibition on hypoxic cell survival and tumour sensitivity towards irradiation.

Material and methods

The effect of eIF4E-overexpression on cell proliferation, hypoxia-tolerance, and radiation sensitivity was assessed using isogenic, inducible U373 and HCT116 cells.

Results

We found that eIF4E-overexpression significantly enhanced proliferation of cells under normal conditions, but not during hypoxia, caused by increased cell death during hypoxia. Furthermore, eIF4E-overexpression stimulated overall rates of tumour growth, but resulted in selective loss of hypoxic cells in established tumours and increased levels of necrosis. This markedly increased overall tumour sensitivity to irradiation.

Conclusions

Our results demonstrate that hypoxia induced inhibition of translational control through regulation of eIF4E is an important mediator of hypoxia tolerance and radioresistance of tumours. These data also demonstrate that deregulation of metabolic pathways such as mTOR can influence the proliferation and survival of tumour cells experiencing metabolic stress in opposite ways of nutrient replete cells.     

Duration of prior gefitinib treatment predicts survival potential in patients with lung adenocarcinoma receiving subsequent erlotinib

Purpose

We investigated survival potential in patients receiving erlotinib after failure of gefitinib, focusing on response and time to progression (TTP) with gefitinib.

Methods

We retrospectively reviewed lung adenocarcinoma patients who received erlotinib after experiencing progression with gefitinib. Our primary objective was to evaluate the prognostic significance of erlotinib therapy.

Results

A total 42 lung adenocarcinoma patients were included in this study. Overall disease control rate was 59.5% (partial response [PR], 2.4%; stable disease [SD], 57.1%). Median overall survival was 7.1 months, and median progression-free survival was 3.4 months. The number of patients who achieved PR and non-PR (SD+ progressive disease [PD]) with gefitinib were 22 (52%) and 20 (48%), respectively. Patients with PR for gefitinib showed significantly longer survival times than those with non-PR (9.2 vs. 4.7 months; p = 0.014). In particular, among PR patients, those with TTP <12 months on gefitinib showed significantly longer survival times than those with TTP ≥12 months (10.3 vs. 6.4 months; p = 0.04).

Conclusions

Erlotinib may exert survival benefit for lung adenocarcinoma patients with less than 12 months of TTP of prior gefitinib who achieved PR for gefitinib.     

Minichromosome maintenance (MCM) protein 4 as a marker for proliferation and its clinical and clinicopathological significance in non-small cell lung cancer

Background

Minichromosome maintenance (MCM) proteins 2-7 form a complex essential for the initiation of DNA replication. In the process to screen expression changes related to growth suppression of non-small cell lung cancer (NSCLC) cells by a cJun dominant-negative mutant, we found that reduced expression of MCM4 was correlated with this growth suppression.

Method

We determined the relevance of MCM4 in proliferation of NSCLC by downregulating its expression with small-interfering RNA in three NSCLC cell lines. We then immunohistochemically analyzed MCM4 expression in 156 surgically resected NSCLCs to correlate clinicopathologic characteristics.

Results

MCM4 downregulation reduced proliferation in two cell lines. MCM4 expression was higher in cancer cells than in adjacent normal bronchial epithelial cells (p < 0.001). High MCM4 expression was correlated with male gender, heavy smoking, poorer differentiation and non-adenocarcinoma histology (p < 0.001, respectively). High MCM4 expression was also correlated with proliferation markers, Ki-67 and cyclin E expression (p < 0.001, respectively). MCM4 expression was not associated with survival.

Conclusion

MCM4 may play an essential role in the proliferation of some NSCLC cells. Taken together with higher expression in NSCLCs and its correlation with clinicopathologic characteristics such as non-adenocarcinoma histology, MCM4 may have potential as a therapeutic target in certain population with NSCLCs.     

Randomized phase II study of gefitinib versus erlotinib in patients with advanced non-small cell lung cancer who failed previous chemotherapy

Purpose

Gefitinib and erlotinib are potent EGFR TKIs, with antitumor activity. In this randomized, single-center, non-comparative phase II trial, the efficacy and safety of gefitinib and erlotinib was evaluated as the second-line therapy for advanced non-small cell lung cancer (NSCLC).

Patients and methods

Patients with locally advanced, metastatic stage IIIB/IV NSCLC who failed first-line chemotherapy and had either EGFR mutation or at least two out of three clinical factors associated with higher incidence of EGFR mutations (female, adenocarcinoma histology, and never-smoker) were eligible.

Results

A total of 96 (48 per arm) patients were randomly assigned to gefitinib- or erlotinib-arm, respectively. Baseline characteristics were well-balanced between the two arms. The response rates (RR) were 47.9% in the gefitinib arm and 39.6% in the erlotinib arm. Median PFS was 4.9 months (95% CI, 1.3-8.5) in the gefitinib arm and 3.1 months (95% CI, 0.0-6.4) in the erlotinib arm. The most common grade 3/4 toxicity was skin rash. Exploratory analyses showed that there was no significant difference in RR and PFS in the gefitinib arm compared to the erlotinib arm (RR (%) 47.9 vs. 39.6, p = 0.269; median survival (months) 4.9 vs. 3.1, p = 0.336). There was no significant difference in QOL between the two arms.

Conclusion

Both gefitinib and erlotinib showed effective activity and tolerable toxicity profiles as second-line treatment for the selected population of NSCLC. We may consider conducting a phase III trial to directly compare the efficacy and toxicity between gefitinib and erlotinib in an enriched patient population.     

Notch1 signaling controls cell proliferation,apoptosis and differentiation in lung carcinoma

Objectives

The role of Notch signaling in human lung cancer still remains unclear, and there has been and stills a debate, on the extent to which Notch ligands and receptors are involved in lung cancer development. This study was carried out to investigate the role of Notch1 signaling in the proliferation and differentiation of human lung cancer cells.

Methods

We used small interfering RNA (siRNA) technology to down-regulate the expression of Notch1 in small cell lung carcinoma (SCLC) cells; H69AR and SBC-3, as well as in non-small cell lung carcinoma (NSCLC) cells; A549 adenocarcinoma (ADC) and H2170 squamous cell carcinoma (SCC). Also, we transfected venus Notch1 intracellular domain (v.NICD) plasmid into the human SCLC line H69 and H1688. In addition, H1688 cells with activated Notch1 were injected into immune-compromised Rag2(−/−) Jak3(−/−) mice for analysis of ex vivo tumor growth and differentiation phenotype.

Results

Notch1 controls cell proliferation and apoptosis in both SCLC and A549; but not in H2170 cell line. Overexpression of Notch1 in SCLC markedly decreased cell proliferation via apoptosis. The subcutaneous tumors arising from xenotransplaned SCLC cells transfected with Notch1 showed “epithelial-like glandular” arrangement, with positive Alcian blue staining and reduction in neuroendocrine markers.

Conclusion

Notch1 up regulation has an inhibitory effect on cell growth and NE differentiation in SCLC, with induction of an epithelial-like morphology of cells in tissue samples. In NSCLC, Notch1 expression has a tumor inhibitory effect on ADC cells, but not SCC cells.     

Stereotactic radiotherapy of histologically proven inoperable stage I non-small cell lung cancer: Patterns of failure

Background and purpose

To report patterns of failure of stereotactic body radiation therapy (SBRT) in inoperable patients with histologically confirmed stage I NSCLC.

Materials and methods

Ninety-two inoperable patients (median age: 75 years) with clinically staged, histologically proven T1 (n = 31) or T2 (n = 61), N0, M0 non-small cell lung cancer (NSCLC) were included in this study. Treatment consisted of 3-5 fractions with 7-15 Gy per fraction prescribed to the 60% isodose.

Results

Freedom from local recurrence at 1, 3 and 5 years was 89%, 83% and 83%, respectively. All 10 local failures were observed in patients with T2 tumors. Isolated regional recurrence was observed in 7.6%. The crude rate of distant progression was 20.7%. Overall survival at 1, 3, and 5 years was 79%, 38% and 17% with a median survival of 29 months. Disease specific survival at 1, 3, and 5 years was 93%, 64% and 48%. Karnofsky performance status, T stage, gross tumor volume and tumor location had no significant impact on overall and disease specific survival. SBRT was generally well tolerated and all patients completed therapy as planned.

Conclusion

SBRT for stage I lung cancer is very well tolerated in this patient cohort with significant cardiopulmonal comorbidity and results in excellent local control rates, although a considerable portion develops regional and distant metastases.     

Dependence of cell survival on instantaneous dose rate of a linear accelerator

Background and purpose

With the development of flattening filter-free linear accelerators for radiotherapy, the instantaneous dose rate has increased by approximately a factor 4. This leads to the question of whether there may be a radiobiological consequence. The present study investigates the radiobiological effect of this high instantaneous dose rate on two cell lines.

Materials and methods

A Varian Trilogy TX linear accelerator was used to directly compare the effect of three different dose rates (5.01, 9.99 and 29.91 Gy/min, with instantaneous dose rates in the pulse of 56.5, 112.8 and 338 Gy/s) on clonogenic survival. V79 and FaDu_DD cells were irradiated with doses in a range from 1 to 10 Gy in order to obtain dose response curves.

Results

For both cell lines, there is not observed any effect of the instantaneous dose rate on cell survival.     

Variation in surgical resection for lung cancer in relation to survival: population-based study in England 2004-2006

Background

Compared with some European countries, England has low lung cancer survival and low use of surgical resection for lung cancer. The use of surgical resection varies within England. We assessed the relationship between surgical resection rate and the survival of lung cancer patients in England.

Methods

We extracted data on 77,349 non-small cell lung cancer (NSCLC) patients diagnosed between 2004 and 2006 from the English National Cancer Repository Dataset. We calculated the frequency of surgical resection by age, socio-economic deprivation and geographical area. We used Cox regression to compute mortality hazard ratios according to quintiles of frequency of surgical resection amongst all 77,349 lung cancer patients, and separately for the 6900 patients who underwent surgical resection.

Results

We found large geographical variation in the surgical resection rate for NSCLC in PCT areas (3-18%). A high frequency of resection was strongly inversely associated with overall mortality (HR 0.88, 95% CI 0.86-0.91 for the highest compared to the lowest resection quintile) and only moderately associated with mortality amongst the resected patients (HR 1.15, 95% CI 0.98-1.36). Compared to the highest resection quintile, 5420 deaths could be delayed in the overall NSCLC group, whereas about 146 more deaths could be expected amongst the resected patients.

Conclusion

The differences in the magnitudes of both the hazard ratios and the absolute excess deaths within resected patients and all NSCLC patients suggests that lung cancer survival in England could plausibly increase if a larger proportion of patients underwent surgical resection. Carefully designed research into the possible benefit of increasing resection rates is indicated.     

A randomised trial of endobronchial ultrasound guided sampling in peripheral lung lesions

Aim

The aim of the study was to evaluate endobronchial ultrasound (EBUS) for peripheral lung lesions and to find the most cost effective combination of sampling techniques.

Materials

264 patients with lesions suspicious of malignancy were recruited in Bergen and Aalesund, Norway from 2005 to 2008.

Methods

The study was a prospective randomised cohort study. EBUS was performed with a 1.7 mm rotating probe. X-ray fluoroscopy was used in both arms. The different sampling techniques were evaluated in a cost-effectiveness analysis.

Results

The detection rate for cancer was 36% in the EBUS group, 44% in the non-EBUS group (ns). Lesions below 3 cm and lesions assumed difficult to reach had significant lower detection rates in the EBUS group. Lesions visualised by EBUS had a higher detection rate for cancer than lesions not visualised by EBUS (62% vs. 19%, p < 0.01). The cost of one additional positive sample was 1211 euro when brushing was added to biopsy. It was not cost effective to add washing or TBNA.

Conclusion

EBUS did not increase the detection rate for cancer in peripheral lung lesions when bronchoscopy was performed by bronchoscopists at all levels of expertise. Biopsy and brushing was the most cost effective combination of sampling techniques.     

Assessment of factors influencing FDG uptake in non-small cell lung cancer on PET/CT by investigating histological differences in expression of glucose transporters 1 and 3 and tumour size

Purpose

The objective of this study was to evaluate the major factors influencing on FDG uptake in non-small cell lung cancer (NSCLC) by investigating histological difference in the expression of glucose transporters 1 and 3 (Glut-1 and Glut-3) and tumour size.

Methods

This study enrolled 32 patients including 9 with squamous cell carcinoma (SCC) and 23 with adenocarcinoma (AC). The AC cases comprised 16 AC with mixed subtypes (AC-mixed) and 7 localized AC in situ (localized bronchioloalveolar carcinoma). Partial volume effect corrected maximum standardized uptake values (cSUVmax) and tumour size were obtained using FDG PET/CT. Glut-1 and Glut-3 expression were evaluated using five-point grading scales.

Results

Overexpression of Gluts was observed at high rates (88% for Glut-1 and 97% for Glut-3). They were mutually correlated. cSUVmax showed better correlation with size than with Gluts overexpression. AC and SCC showed a high positive expression rate for both Glut-1 and Glut-3, although the degree of overexpression was significantly higher in SCC than AC. In addition, localized AC in situ revealed a considerably higher positive expression rate and similar degrees of overexpression for both Glut-1 and Glut-3 compared with AC-mixed. By contrast, localized AC in situ alone was significantly smaller in both cSUVmax and size than either SCC or AC-mixed. No significant difference was found in cSUVmax or size between SCC and AC-mixed.

Conclusions

The FDG uptake of NSCLC might be dependent on size rather than on overexpression of Glut-1 or Glut-3. Low FDG uptake in localized AC in situ might result from its small size rather than Glut overexpression.     

Treatment decision-making for advanced non-small cell lung cancer and differences among European countries: 1st AIOT-ETOP meeting

Introduction

The Italian Association of Thoracic Oncology (AIOT) and the European Thoracic Oncology Platform (ETOP) realized the first conjunct educational meeting, open to European oncologists involved in the treatment of thoracic malignancies, entitled “Advanced non-small cell lung cancer: new perspectives in first-line setting”.

Methods

The educational meeting included 8 interactive talks, held by European key opinion leaders, and 5 related clinical cases in which the attendees, divided in working tables based on their country origin, were involved for interactive discussion. The aim of this course was to elucidate the differences or similarities among the European countries in the first-line treatment of patients affected by advanced non-small cell lung cancer (NSCLC).

Results

Twenty-two attendees of the following countries participated: Austria, France, Italy, Spain, Swiss, and UK. As expected, some discrepancies between the groups were identified concerning the approach to the diagnostic phase, the choice of first-line regimen, the duration of treatment and the use of maintenance therapy. These discrepancies were mainly due to familiarity with specific therapies and lack of access to certain therapies due to local regulatory issues.

Conclusion

The European Medicine Agency grants marketing of drugs in all Europe, regulatory agency of each country can register the drug, but can also deny public reimbursement thus restricting the options of the oncologist. The European Oncology Associations should join to their effort to achieve a uniform access to the cancer therapy for all patients in Europe.     

Dosimetric Evaluation of a Conformal Seven-field Coplanar Technique for Planning Lung Stereotactic Body Radiotherapy

Aims

To assess the effectiveness of a seven-field coplanar planning technique in producing dosimetrically acceptable treatment plans when measured against the dose constraints of the ROSEL trial quality assurance working party.

Materials and methods

Nineteen patients with non-small cell lung cancer staged at T1-T2 underwent computed tomography scanning in preparation for lung stereotactic body radiotherapy treatment. Planning target volumes ranged from 17 to 100 cm³. Dose plans were created with the enhanced collapsed cone algorithm on the Oncentra Masterplan treatment planning system using an open-field conformal coplanar technique. The plan acceptance criteria in the ROSEL study protocol were used for critical evaluation of the plans to determine their suitability for clinical use.

Results

Clinically acceptable plans were produced for 17 of the 19 patients with no more than two minor dosimetric deviations from protocol. The two patients where conflicts between adequate tumour coverage and unacceptably high doses to surrounding tissue could not be reconciled were characterised by low average Hounsfield Unit values in the planning target volume, i.e. less than about -700 Hounsfield Units. This tissue density was comparable with that of the surrounding healthy lung tissue.

Conclusion

This planning technique produces clinically acceptable plans for most lung stereotactic body radiotherapy patients without the need to resort to more complex methods of treatment planning and delivery.     

No evidence of an association of ERCC1 and ERCC2 polymorphisms with clinical outcomes of platinum-based chemotherapies in non-small cell lung cancer: a meta-analysis

Background

The nucleotide excision repair (NER) pathway modulates platinum-based chemotherapeutic efficacy by removing drug-induced DNA damage.

Methods

To summarize published data on the association between NER genes and responses to platinum-based chemotherapies in non-small cell lung cancer (NSCLC), we performed a meta-analysis of 17 published studies of ERCC1 C118T/C8092A and ERCC2 Lys751Gln/Asp312Asn polymorphisms, including 2097 cancer patients. Primary outcomes included objective response (TR) (i.e., complete response + partial response vs. stable disease + progressive disease), progression-free survival (PFS) and overall survival (OS). We calculated odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) to estimate the risk or hazard.

Results

We found that none of the ERCC1 C118T/C8092A and ERCC2 Lys751Gln/Asp312Asn polymorphisms alone was statistically significantly associated with objective response, PFS and OS in NSCLC patients.

Conclusion

There is no evidence to support the use of NER ERCC1 C118T/C8092A and ERCC2 Lys751Gln/Asp312Asn polymorphisms as prognostic predictors of platinum-based chemotherapies in NSCLC.     

TS expression predicts postoperative recurrence in adenocarcinoma of the lung

Background

Not all patients with lung cancer require postoperative adjuvant chemotherapy after a complete resection. However, no useful markers for either selecting appropriate candidates or for predicting clinical recurrence exist.

Methods

Tumor specimens were collected from 183 consecutive patients who underwent a complete resection for lung adenocarcinoma from 2003 to 2007 in our department. We analyzed the thymidylate synthase (TS) and dihydrofolate reductase (DHFR) expressions in the primary lung adenocarcinoma by immunohistochemisty.

Results

The strong expression of TS and DHFR was identified in 39 (21.3%) and 120 (65.6%) patients, respectively. The strong TS expression was identified in 11 (39.3%) of 28 patients and 28 (18.1%) of 155 patients in patients with and without recurrence, respectively (p = 0.012). The strong DHFR expression was also identified in 23 (82.1%) and 97 (62.6%) of the patients with and without recurrence, respectively (p = 0.045). Logistic regression models indicated the strong TS expression to be an independent factor for tumor recurrence. The strong TS and DHFR expression was associated with a poorer disease-free survival (DFS) according to the survival analysis. A multivariate analysis demonstrated the strong TS expression to be independently associated with an increased risk for poor DFS.

Conclusions

The strong TS expression may be a useful marker for predicting postoperative recurrence in patients with lung adenocarcinoma following surgery.